Dual Carbs on 4 valve Rajo

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Model T Ford Forum: Forum 2016: Dual Carbs on 4 valve Rajo
Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth in Alabama on Friday, April 22, 2016 - 12:58 am:

I like different stuff, I want my speedster to look and be different but go really really fast and handle well and stop well. Here's my latest updates. I have been working on swapping from a low head with a single Zenith S4BF carb to a Rajo 4 valve with twin S4BFs.

Started out wanting to keep my two carbs in roughly the same place as when it was mounted as a single with a stock head. So I made this dual intake really long and sweeping and while it looks cool it sucks.



Absurdly hard to get the car started. After talking with some folks the general consensus was that the intake was just took long and my fuel was probably going from a nice fine mist to fat droplets (those don't explode well) before getting to the engine. The car did start like this though and runs and sounds very mean. Even though it didn't run what I consider very well, a short test drive revealed a DRAMATIC increase in horsepower and acceleration. Once I get the bugs ironed out this girl is going to be scary fast. I may need some slightly smaller jets in the carbs but that's a separate issue for another post.

After some input and suggestions I have moved on to iteration number 2.



This dramatically shortened the intake and brought the carbs a lot closer, along with a much beefier tube to balance the two carbs front and back. I haven't gotten a chance to try it like this yet, need some new fuel line to get the gas where it now needs to go.

Which brings up an interesting issue I wanted to ask for some input on. Based on my current carb location, if I were low on gas and tried to climb anything steeper than a 10% grade, I'd be in trouble and run out of fuel. I have a 6 volt battery and alternator but I'd really prefer to stay away from an electric fuel pump. With my high tension magneto the engine is entirely self-contained and my battery only runs lights and horn.

Does anyone on here run something like a Stewart Warner vacuum fuel pump? It looks like a good solution for me from the little I've been able to find out. It's a small fuel tank that would be mounted on my firewall (it'd be inside the body as I don't have room under the hood, not to mention it would be terribly ugly) but it gets filled from the main tank via intake manifold vacuum and then feeds the carbs.

Would it even work? If I got one off eBay and rebuilt it would my engine create enough vacuum to make it work and it keep the carbs fed?

Is there something similar that would work better? This isn't a pressing issue as I don't even have the car quite running, much less low on fuel up steep hills. But it looks like I could get a fuel pump/tank like this and rebuild it for less than $100.

Lastly, if you don't like my car or what I'm doing cause it's not "stock" then please keep the sarcastic and non-helpful stuff to yourself. I don't berate the purists who run NOS air in their white tires.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jeff Hood -Long Beach, California on Friday, April 22, 2016 - 01:11 am:

Hand operated air pump to pressurize the tank? Many old cars used these, and some even pressurized the fuel tank with exhaust. Sounds dangerous, but there is little or no oxygen in exhaust to support combustion.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Donnie Brown North Central Arkansas on Friday, April 22, 2016 - 01:55 am:

Seth, I have had a little to do with the Stewart vacuum tanks. They work good, when they are working. They are somewhat of a trick to get to work reliable, but lots of folks run them. The main problem is with the top casting on the tank. Most are made of pot metal and are cracking. I have seen a few steel top tanks, but they are kinda scarce. When you get the bugs worked out and you are sure you need a vacuum tank let me know. I have a couple extra. I may even have a steel top version. But I need to look for it. I guess that's all I can say for now. I had some real sarcastic, "smart ass" remarks but since I can not use them, have fun and be safe..... :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Thomas on Friday, April 22, 2016 - 03:55 am:

Seth, i run a SW vacuum tank and it works with no problem, so far. Ofcourse i have restored it and one can find new gaskets and spring on ebay.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Walt Berdan, Bellevue, WA on Friday, April 22, 2016 - 01:23 pm:

If you want to avoid an electric pump, I'd go with a hand air pump. Pretty simple and a common practice back in the day.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth in Alabama on Friday, April 22, 2016 - 01:33 pm:

That looks like a sweet ride Thomas, would you post more pics of the rest of it?

Donnie, definitely let me know if you have one or can put together a complete one from the ones you have. If it works like I think it should I can get it going and then just not worry about it.

Jeff I think I'm too lazy to have to pump my car to keep her going. The exhaust to pressurize the tank is intriguing but seems like it would take some careful plumbing and I might need more back pressure on my exhaust. I won't rule that out though.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth in Alabama on Friday, April 22, 2016 - 06:44 pm:

New intake works great! Much easier to start the carb. Idles down nice and smooth. Just need to tweak the throttle cable a little so it pulls both carbs evenly. Also going to drill and tap the intake so I can test the vacuum at both carbs and balance them.

Hopefully I'll get her all back together and go for a test drive soon.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Chad Marchees _____Tax Capital, NY on Friday, April 22, 2016 - 07:37 pm:

Seth, it is unfortunate the long setup did not work well as it was very unique. It reminded me of the old Chrysler long ram intake.

The new setup still looks good to, so hopefully the shake down run will prove to be the same as the garage tune. FYI, when you settle on your design, you can smooth out all your welds and have it ceramic coated for a long lasting finish. They make it in different finish colors nowadays.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Donnie Brown North Central Arkansas on Friday, April 22, 2016 - 08:52 pm:

Seth, Ill try and remember to look for the vacuum tanks tomorrow. If you do not hear from me in a day or two, you may need to remind the "old man" Looks like you should achieve a pretty good "plenum effect" with the setup you have now. Have you figured out how to attach and deploy the parachute for stopping yet.... :-) :-) Looks good.... Have fun and be safe....


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett - Australia on Saturday, April 23, 2016 - 12:38 am:

Seth, your carbs are ideally lined up to use a single cable to the pedal. That way you will not have adjustment problems getting them synchronised.
I would be looking to fit longer throttle plate shafts and interconnecting them with a solid linkage. The synchronising is done before the linkage is tightened. You might even be able to bypass the cable and go with the standard rod linkages.
The twin carburetor setup on the early Mini Coopers had a brilliant setup like this.

Hope this helps.
Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth in Alabama on Saturday, April 23, 2016 - 01:12 am:

Allan, I would love to be able to run solid rod linkages. At the moment though I'm just not sure how I could go about it. I kind of played with it at first but it was going to be an engineering undertaking I wasn't ready for in order to get both carbs to pull evenly. If you look at the picture, the throttle arms start out towards the passenger side and pull across the car to the drivers side as they open up. I can swap them front and back and that will put the arms a lot closer together, but I'm still not sure how to design a solid linkage that would be adjustable for the individual carbs but still pull both evenly. I'm not opposed to doing it this way, in fact I'd prefer it. I just can't picture how to go about it.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth in Alabama on Saturday, April 23, 2016 - 01:14 am:

Wait a minute. I might be tracking now on what you're talking about. Have a longer shaft through the front and rear carbs and then use that to connect them, an arm off of that center arm would be easy to hook up.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth in Alabama on Saturday, April 23, 2016 - 01:26 am:

Something like this - if the shaft through the throttles is longer toward the center I can make a center shaft with one end locking on to one carb and the other end with a sliding collar that will lock on to the other throttle shaft.

You're a genius. That's so much simpler than I was imagining.



Just a 90 degree arm off that center adjustable shaft will let me run a single rod with a couple simple bends to the stock Ford location.

Just need to pick me up some 1/4" brass rod to make some new throttle shafts. Thank you sir!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Erik Barrett in Auburn Ca. on Saturday, April 23, 2016 - 02:50 am:

Seth, the shorter intake runners look good, will give you better starting and drivability. A vacuum tank is a reliable fuel delivery system if in good order. They were used successfully on many cars of the era. I use them on Buick and Dodge Brothers cars myself. I think the downside for you is that it should be quite a bit above the carb to provide adequate gravity fuel pressure. This could look out of place on a speedster above the body line. If you have a battery and alternator, you could use an electric fuel pump and have a hand pump as emergency backup. They look cool on speedsters anyway. You would need a way to close up the fuel tank vent when using the hand pump, if you ever need to. Just some thoughts, opinions will vary.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett - Australia on Saturday, April 23, 2016 - 07:50 am:

You've got it Seth. What you meed for the connection is what we call W clips. As the name says, they are shaped like a W. There is a hole drilled clear through so the clip will go on over the shafts. The end legs of the clip are split and there is a pinch bolt to tighten the clip around the shaft.
Once the carbs have been synchronised, the clip is tightened to make the solid connection. Let me know if I can help locate them if you cannot find them locally.

Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett - Australia on Saturday, April 23, 2016 - 07:58 am:

Now you've got it Seth. The linkage can be connected to the throttle plate shafts using what we call a W clip, so named because of the shape. There is a hole the size of the shafts drilled clear through the clamp. The end legs of the W clip are slotted and a pinch bolt locks the clip around the shaft. The carbs are synchronised first and then the clips are done up to make the linkage.

Let me know if you cannot find them locally and I will see if I can get some here.

Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Frank van Ekeren (Australia) on Saturday, April 23, 2016 - 08:09 am:


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth in Alabama on Saturday, April 23, 2016 - 02:28 pm:

I've been trying to google some W clips but I'm not finding anything I can buy. The only thing I've seen so far is on eBay in Australia and they're really expensive, like $26 each. Does anybody have a source for these that is a little more reasonably priced?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Walt Berdan, Bellevue, WA on Saturday, April 23, 2016 - 03:49 pm:

A little less but not cheap from a Volvo parts place - http://212.247.61.152/us/main.aspx?page=article&artno=71676

I suspect most of the 50's and 60's vintage 4 bangers with dual carbs used these. If there is a shop near you that works on British, Japanese, Volvo, other European or other 4 cyl cars they may have them. I've found a guy in my area that just works on the older stuff, maybe you can find one near you.

Random thought, might work but not as pretty - if there is enough of a stub of the shafts exposed on the carbs you might be able to use a piece of fuel line and tiny hose clamps to link the intermediate shaft to the carb shafts. Shaft ends should touch or be very close to each other inside the piece of line to limit any flex in the linkage. Maybe an interim thing while you are testing your options?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth in Alabama on Saturday, April 23, 2016 - 05:40 pm:

Walt the shafts on the carb throttles are 1/4", do you know what size the hole is on the clip that you linked?

I'm pretty sure I can just make me some instead of spending $20 each on them. I'll get some thicker sheet metal and then just bend it over some flat bar, drill my holes and then cut the groove on top, 4 nuts and bolts and 8 washers and I'll be set. I'm waiting on my 1/4" brass rod to show up in the mail anyway.

The center section I'm going to make steel so that I can weld on what will be my actual throttle arm that will get linked to the Ford lever. I have 4 final exams next week though so the speedster will just have to wait for more attention until next weekend.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett - Australia on Saturday, April 23, 2016 - 06:20 pm:

Good one Frank. They could be made from sheet steel, but I have always thought they were of harder material than that. There's your guide Seth.

Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ed Archer Hayward, CA. on Saturday, April 23, 2016 - 06:21 pm:

Seth I have cars with vacuum tanks and hand pump systems, both work great with no tinkering issues and I never have to worry about my battery being too low to run a modern electric pump or the pump failing while on a trip. As Eric says the vacuum tank has to be higher than the carbs. Your comment about being lazy not wanting to pump all the time. No one is lazier than me. Normal driving you pump a few strokes maybe every 10 to 15 miles. On a warm day the sun expands the air in the tank and you seemingly go forever without pumping. Typically You should have an air gauge on the dash and a half to one pound of pressure is all you need. I run quite a while with the gauge reading nothing which tells you you don't need much air.
Ed aka #4


Top of pagePrevious messageNext messageBottom of page Link to this message  By Harold Schwendeman - Sumner,WA on Saturday, April 23, 2016 - 06:35 pm:

Ed Archer - Correct me if I'm wrong, but from what I've read in the past, I think another indication that very minimal pressure is needed is the fact that the very slight pressure produced by using the exhaust pressure system seems to be quite sufficient.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Frank Harris from Long Beach, CA on Saturday, April 23, 2016 - 06:44 pm:

With both carburetors in line both throttle shafts are in line and you must use a push-pull rod to the accelerator lever. Using this system will get the front carburetor out of adjustment because the rod will grow as it warms up and the front carburetor will be advanced or in other words the butterfly valve will be more open than the back one. You could adjust them while hot and then they will start out wrong but will self adjust as they warm up

I always run my dual carburetors turned sideways so you simply lift the rod connecting the carburetors and it will make no difference in you synchronization as they warm up and grow and they will.

The picture below is of my 1951 Ford flathead six with dual carburetors actuated by the lift rod connected between them. The rod is located just under the fuel line in the picture right above the fender line. They are in front of the finned aluminum intake manifold.




ford 6


Top of pagePrevious messageNext messageBottom of page Link to this message  By Les Schubert on Saturday, April 23, 2016 - 07:05 pm:

This has turned into a really informative a thread (at least for me). Lots to think about and learn from

Thank you all


Top of pagePrevious messageNext messageBottom of page Link to this message  By Jeff Hood -Long Beach, California on Saturday, April 23, 2016 - 07:49 pm:

Seth, a couple of sleeves with some set screws would work too, and if you can't find any, they would probably be easier to make than the "W" clip.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Les Schubert on Saturday, April 23, 2016 - 08:14 pm:

The problem with set screws is typically they make a indentation in the shaft and then always want to return to that. The external clamping sleeve deals with that issue and so will allow small adjustments to be easily made and then remade as needed!!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett - Australia on Sunday, April 24, 2016 - 08:20 am:

The beauty of the W clip as Frank shows is that it can handle changes in length of the connecting rod due to heat expansion. The ones I am familiar with are made of spring steel, and you can squeeze them between your fingers, so they soak up any changes in length of the rod. The clamping bolts allow the clamp to be fitted in any orientation. On twin SU setups, one is tightened first, the carbs are synchronised, and then the second clamp is tightened to maintain that setting.

Hope this helps.
Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Frank Harris from Long Beach, CA on Sunday, April 24, 2016 - 08:38 am:

But that problem go's away if you rotate the carburetors 90 degrees and use a lifting rod like my picture shows.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Walt Berdan, Bellevue, WA on Sunday, April 24, 2016 - 12:50 pm:

Seth - I measured the shaft for the Volvo link I sent. It's 5/16 so no help here. Should have checked that first, oops.
Walt


Top of pagePrevious messageNext messageBottom of page Link to this message  By Rob Heyen - Eastern Nebraska on Sunday, April 24, 2016 - 01:11 pm:

Seth,

I've read a few posts, not the entire thread.

A few thoughts...... Our Model K has an incredibly long intake riser to the manifold, and it takes a few chokes even when warm, or richen the mixture to start. It seems your setup shouldn't be any more difficult to start from than the K.

We've talked about pressurizing our gas tank (just a pound or two) with a regulator and line from the exhaust to the tank.

Neat setup, I think you'll have a great time, and lot's of quick power with the two carb overhead setup. Thank you for sharing the pics and info,

Rob


Top of pagePrevious messageNext messageBottom of page Link to this message  By Thomas on Sunday, April 24, 2016 - 03:40 pm:

Seth, itīs a -23 T with a -28 chevy OHV head. Model A steering and rims.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett - Australia on Sunday, April 24, 2016 - 08:15 pm:

Seth, I forgot to mention that the W clips will also compensate for some mis-alignment in the shafts too. They flex if they need to.

Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth in Alabama on Monday, April 25, 2016 - 06:03 pm:

Hey Allan, I sent you a PM. Does anyone know where I could purchase some w-clips? I'd like to get some that are already made and ready to go if possible. the shaft hole needs to be 1/4".


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett - Australia on Monday, April 25, 2016 - 07:18 pm:

Got it Seth. Been on line to find some. Will advise findings. It looks like 5/16" is the only size hole, but one site shows a split bushing to get 1/4" throttle shafts up to 5/16" linkage size.

Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Erickson on Tuesday, April 26, 2016 - 04:38 pm:

Do you have access to a lathe? You could take a 1/2" or larger rod and drill the center out to 1/4" then drill and tap a couple of set screws from the side.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett - Australia on Tuesday, April 26, 2016 - 05:23 pm:

Seth, go to www.revheads.com.au and look under SU and Stromberg carburettor accessories. Twin pack of W clips, AU$20.95 about US$15. You will need to make the split bush to get your shafts up to 5/16".

Hope this helps.
Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Ed Archer Hayward, CA. on Wednesday, April 27, 2016 - 05:18 pm:

Harold, you're right. The exhaust pressure system is enough for single or duals.

Ed aka #4


Top of pagePrevious messageNext messageBottom of page Link to this message  By Joe Meakin on Thursday, April 28, 2016 - 05:59 am:

You could always take a look here on the SU Carb Website where they seem to have what you're looking for. As Allan said the clips are 5/16 but they do 5/16 to 1/4 adaptors.

http://sucarb.co.uk/linkage-parts/couplings.html


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett - Australia on Thursday, April 28, 2016 - 09:38 am:

Joe, I found them on the SU site first, but didn't like the price!!! The pair on the Revheads site are much better value. The split bush illustration shows how the adaptors could be made.

I've had them in my stuff before when working on twin SU setups. When the motors went east-west, the twins setups had opposing fuel bowls and the linkage setup did away with the W clips and went to a much better system. I have no doubt chucked them out!!

Allan from down under.

Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth in Alabama on Saturday, May 07, 2016 - 08:44 pm:

Well! It's taken a while but I think I'm getting somewhere. The car starts much easier. My only concern is I might need to get some smaller jets. I have the idles on both carbs adjusted to the extreme end. I'll see if I can get a couple sets made that are a little smaller and then a little smaller than that, then play around with what works the best.

I do need to make my throttle linkage adjustable as its a wee bit long, although that's better than a wee bit short.





I also need to make some small metal pans because the carbs drip a little gas when choked and I'm having to wipe it up off my hood shelf. I'll probably replace the hood hooks with a small post and pan so the gas drips outside.

HOLY SMOKES! I only drove around the neighborhood but the acceleration and power is just downright scary. I'm going to keep slowly but surely taking longer trips but I'm excited to get out on the highway and let her rip. I'm confident that the top end will be somewhere very far above 70 mph and I'll never find out what her top speed really is.

Even with the shorter intake, she is crazy loud now. Used to be about the same as a stock T when I had the exhaust flap closed. Now I think she might be louder with it closed than when it was open with the low head. Definitely breathing a LOT better. Also, I'll probably end up with a half hood at best. It looks too wicked to cover that engine up.

Thanks to everyone for your input and help.


Top of pagePrevious messageNext messageBottom of page Link to this message  By John Noonan - Norton, MA. on Saturday, May 07, 2016 - 08:55 pm:

Looks fantastic Seth...zoom zoom. :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Chaffin......Corona, CA on Saturday, May 07, 2016 - 10:28 pm:

Looking good Seth! Keep us posted regarding your progress. Maybe a YouTube video is in order!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stan Howe Helena, Montana on Sunday, May 08, 2016 - 01:13 am:

Seth, I have a whole chingo of jets for those, tell me what number you are running and I should be able to find some smaller, some bigger. Whatever you need. The real trick, of course, is to make an adjustable main jet. It's pretty simple.

They truly are great speedster carbs!!!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Donnie Brown North Central Arkansas on Sunday, May 08, 2016 - 01:47 am:

Seth, looks good, we need a video.. :-)... But I want to also hear about the Rajo 4 valve. Any problems with it. ???? I heard all the horror stories about the 4 valve heads, but I have found no issues with mine so far, and seems like yours went on OK ... Im not sure which airplane it was (I think the blackbird) that leaked like a sieve out the fuel tanks and such, till it was flying at over the speed of sound and then it quit leaking. Maybe you just need to go faster to get the fuel leak stopped .:-) have fun and be safe ....


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth in Alabama on Sunday, May 08, 2016 - 09:30 am:

LOL yes! THAT is definitely the answer Donnie. If I go fast enough the engine will suck all of the fuel up before it can leak. I really did laugh out loud. And you are correct, the SR-71 Blackbird was made with titanium (I think) skin - the panels were loose when cold but once it got up flying they'd heat up and expand and seal. That plane is wild. The faster it goes the less fuel it uses. I wish my cars worked like that.

Uncle Stan! Here I was thinking I'd need to take the ones out I've got and hope my machinist could replicate them and it turns out to be loads easier than that. I will pull the ones I have and let you know. That adjustable main jet sounds like the ticket. Is that something I could buy from your or would I need to send my carbs to you for that? I'll probably see if I can play with the jets for now and hopefully drive a lot while the weather is nice.

I'll make a video for everyone, both of the car running and then the absurd acceleration.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Stan Howe Helena, Montana on Sunday, May 08, 2016 - 09:38 am:

You could buy an adjustable jet from me but right now I don't have time to make one. I am buried, buried, buried in work with people trying to get the cars ready for touring season. I've been out of the shop some, too, we have a couple good auctions coming up and I've been spending some time working on those. I'm headed out today to get the only unrestored 1915 REO close coupled roadster in the world running and driving for the auction. There are, by the way, a few pictures of it on frontrangeauctions.com and will be more + a you tube video by tomorrow or Tuesday.

Anyway, if you can pull the main jet and tell me what the number is I'll see what I have.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth in Alabama on Sunday, May 08, 2016 - 10:04 am:

Okay, I appreciate you digging me up some jets. I'll get the numbers off mine today and send them to you. No problem on being busy. When things slow back down a little (if that ever happens for you) put me down for two adjustable main jets.

Thanks!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth in Alabama on Sunday, May 08, 2016 - 01:30 pm:

Wooooo holy mackerel! I forgot to make a video but I cranked her up and went and got gas and then jumped on the interstate for one exit and zoomed up to 60 like it was nothing. Gobs and gobs of power.

So - here's what happened. I'm gonna change the oil and double check but the faster I went the hotter she got, slowing back down would bring the temp back down. Which makes me think she's running lean? I'll try again later today after I change the oil. It was pretty noticeable though. She'd heat up on the moto meter whenever I'd run faster, but she'd cool on down once I got back to idle. Also, she ran hotter in general. Normally my motometer is about halfway between the bottom and the center line, now it stays right about the center line.

Stan - the main jets in both carbs are marked 19. Both of the idle jets are marked 18 and 3. The 18 is on one side of the screwdriver slot and the 3 on the other. I'm not sure which way means what but on both carbs I get the smoothest running with the idle adjustment knobs turned almost completely in. I'm out of my depth here. I don't know if that means I need smaller jets or bigger ones. Lol in my mind smaller jets means less fuel thus more lean. Or, I'm essentially reducing the whole carburetor with smaller jets and that should bring me back more in the middle of the adjustment. I have no idea what I'm talking about though.





I welcome your input on what I should try next.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Seth in Alabama on Sunday, May 08, 2016 - 04:42 pm:

Also, I wrote that backwards. The mains are the 18/3 and the idles are 19.


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