It used to fire a bold blue yellow spark but when I spent a bunch of $$$ to rebuild the '11 Hupp engine, the spark produced went from non-existant to very minimal. Probably condenser, huh? Anyway, I've researched the old threads on several forums pertaining to the DU-4s and have concluded I want to send it off. Any recommendations from experience? Thanks to all, and I'll see ya' at Chickasha
Howdy George! I have a DU-4 firing my '14 speedster. Steve Belanger at Mainely Magnetos does excellent work (up in the state of Maine). www.mainelymagnetos.com
Are your plugs gapped correctly? If they're gapped too wide it will burn the mag out. I believe Steve recommended .018", which is much tighter than normally seen on a T or similar - it's just how the high tension mag prefers to work.
Theres a guy named Marks Magneto that rebuilds mags. He's done a tractor one for me. Mark's number is 1-860-537-0376. He is in Colchester, CT.
Has an entire chapter on the DU, and is good overall
Really amazing - the answers that appear on this Forum.
Just ask and an answer appears...no need to scroll through a whole litany of sub sets of ancillary sub-forums to get results....
just saying that this Forum is very nice!
(Thread Drift coming???)
If your magneto was good and is no longer good, check the points, they must be clean, flat and with a gap of 0,016 inch
Check also the distributor, the contact that sends the spark to either 4 terminals.
That's all you can do yourself.
If it is the condenser or insulation of the coil or if magnet needs recharging you have to give it to a rebuilder.
The problem could be also that you don't crank the engine fast enough to have a good spark ... (I had this problem)
Don't forget it needs a very good ground to the mounting base.
Geo., I have a couple DU's for parts. If you find you need something, let me know.
I will second the make sure the point are clean. Even a little oil or oxidation from sitting will mess them up. Clean then pull a piece of clean card stock through the points to wipe them off.
Here is a bit, I have the complete chapter from Dyke's 1918 issue. Send me your e-mail and I will send you the chapter. Is is all you need to know about a DU4 I MADE THIS TESTER from a page in the chapter. You run the mag on a bench with a rubber hose connected to a 1/2 inch drill.
Be aware that the condenser for the DU4 is built into the end of the armature. Not a conventional condenser like you see in a WICO or others. So it is not a "do it yourself repair" I had an armature/condenser rebuilt by Bill Lampoloplis (sp)he doesn't have the best reputation. Although I had no complaints. Check the Smokestack forum, either in hit/miss engines or magnetos, you will find out who are your best bet.
I HIGHLY RECOMMEND STEVE AT MAINLEYMAGNETOS.COM. DOES GOOD WORK AND STANDS BEHIND IT. TREATED ME MORE THAN FAIRLY WITH A LAST MINUTE PROBLEM.
Its absolutely incredible to me the wealth of knowledge out there and the quickness with which its shared. Thanks again! Frank, for some time now I get a little yellow explosion thingy outlined in red when I click on a name seeking a profile. The computer clicks and its an icon thingy where I can't see either the member's profile or any other I Net reference - like a eBay reference. . . . Would you please send the complete Dyke's chapter? Mine is a brass base. Many thanks!
I get the same little explosion thingy.
If I right click on the name I get a menu and click on OPEN at the top.
Works for me.
Try left click
Bosch mags are dependable HOT magnetos.........right up until they quit.
They have wound armatures, the condensers are part of the armature assembly and it takes an act of congress to remove the bakelite collector ring without breaking it.
Unfortunately the symptoms of a bad condenser and a weak coil are identical......in most cases a good spark or two which dwindles to nothing.
As mentioned above the condition of the points is paramount and the points opening is specified in Bosch literature as being 1/64" (.015") or "the thickness of a worn dime" in old speak.
That opening isn't carved in stone and many times it takes some playing around to find a points gap that provides the best, all around from retarded to advanced, spark.
Marks Magneto Service in Conn has done several mags for me including aDU4. He always rewinds them so that they are good for many years! He even setup in the Red field AT Hershey every year and seems to be a great Guy!! John - Very cold In Iowa
Ha! Thanks Bob Gruber! I did the right click on the name thing, then 'Open' and I can again see ya'll's profiles! . . .Yes, it is acceptable to use two apostrophes when referencing a southern contraction ;o)
Glad to help George.
I'm no computer geek...my daughter showed me that some time ago.
How is the project coming?
Saw this, and wondered if you want another:
I know nothing about it - I just saw the ad.
Thanks for the continued interest Dave. I called Mark's Magnetos yesterday to confirm their receipt of my DU 4. The lady answering the phone said they did, indeed, receive it. Before I sent it Mark asked when I needed it back and I mentioned a local car show toward the end of April and he said he 'might' have it back home by the end of March !