Bike cuts out every mile... leave it and it re-starts?

[1340evo]

Hi All.. just had the bike in bits and replaced the gearbox output shaft and fitted a better 1990 clutch.. works a treat.. but I still have the issue I was looking for in the first place when I found my 1989 clutch (taper) to be split.

So.. I have a digital meter strapped to the bike... anything over tickover and its showing 14.7 volts... so that sounds okay if maybe a bit high (did see a 26 for a second flash up but onlt once?)... Not opened it up much but think 14.7 it a typical running charge... its a new reg also?

so the bike will run for about 1 mile and then starts poping and banging.. and stops.. you can feal it go weak coming onto power and then it just cuts out... leave it 10 mins and we are off again.

Now I'd say that was the coil.. but its only 2K old?.. the pickup is the same, where as the CDI is 35K I think.

any thoughts?.. do CDI's play up.. or just go dead?

Am I getting too many volts and have I part cooked something?

All earths are good and double checked

any thoughts appreciated before I start buying and trying

Cheers

[Mule]

Sounds like the ignition, What ignition is it?

[1340evo]

its the std HD CDI box...

This coil... https://www.motorcyclestorehouse.com/product/502941
accel supercoil

and a 741882 Zodiak pickup plate....

[Mule]

http://www.ebay.com/itm/Ultima-Programmable-Ignition-Module-for-Harley-EVO-Sportster-and-Shovelhead/332319123404?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649

[Mark222]

Sounds like a coil I have go south before.

Mark

[Evo160K]

Have you ruled out fuel?

[1340evo]

Ultima Programmable Ignition Module for Harley EVO, Sportster and Shovelhead

yes.. did look at that £210 in the UK... are they reliable??..

[1340evo]

Have you ruled out fuel?

Just taken the pipe off the carb and run about 2 ltrs in 1 min... so nothing there
Also carb new and set right.. so that should be fine...

[1340evo]

Sounds like a coil I have go south before.

Mark

That was my thoughts but its new... and Accell or so it says on the reciept... does this look like an Accell coil?

[attach=0]

[Deye76]

Any paperwork with that coil? If using a Ultima programmable ign., coil primary resistance should be in the 2.5 to 3.5 ohm range. 

[thumper 823]

Old trick-
Pack a can of electronics cleaner or anything that gets instantly cold..
When the bike quits,  spray the suspect part, and try starting.
When you cool off the right item it will fire up.

[JamesButler]

Seems like it could only be one of four issues: fuel flow, ignition coil, ignition module or ignition switch.

Maybe a fuel issue, if there is debris in the carb float bowl that gets sucked up to the mouth of the needle jet and blocks the flow. I had a piece of a leaf do that to me once.  Bike would start, get it up to full speed then half speed at full throttle as the leaf got sucked up to the jet.  Would settle back down to the bottom of the bowl once the bike shut down.  Then, the whole process would begin again.

Might also want to check your tank to make sure not rust chips are swirling around and blocking the fuel line to the petcock.  Also, check the petcock to make sure it is not clogged.

However, my guess is that it's an ignition coil (wire) connection problem.  Check the three wires behind the coil to make sure they are tightened down and clean.  Or your coil could simply be failing.  I've experienced both those scenarios, as well.  Often, when the coil fails, it begins to internally melt down and you'll see some sticky residue substance leak from it down onto your cylinders case and case.  Stock Coils often fail after a bike has been hopped up; too much strain on it.

Could be your ignition module, but it seems to me that the bike wouldn't start let alone run properly albeit for a mile or so, if the module crapped out.

Lastly, check behind your ignition switch (not the coil and not the module) where your key inserts.  Make sure those three wires are not only connected to their posts but also securely connected.  I've also experienced that issue where one wire actually was fraying and hanging on by a thread.

Oh yeah, maybe a fifth issue: check to make sure the battery terminals are secure.
 

[1340evo]

Seems like it could only be one of four issues: fuel flow, ignition coil, ignition module or ignition switch.

Maybe a fuel issue, if there is debris in the carb float bowl that gets sucked up to the mouth of the needle jet and blocks the flow. I had a piece of a leaf do that to me once.  Bike would start, get it up to full speed then half speed at full throttle as the leaf got sucked up to the jet.  Would settle back down to the bottom of the bowl once the bike shut down.  Then, the whole process would begin again.

Might also want to check your tank to make sure not rust chips are swirling around and blocking the fuel line to the petcock.  Also, check the petcock to make sure it is not clogged.

However, my guess is that it's an ignition coil (wire) connection problem.  Check the three wires behind the coil to make sure they are tightened down and clean.  Or your coil could simply be failing.  I've experienced both those scenarios, as well.  Often, when the coil fails, it begins to internally melt down and you'll see some sticky residue substance leak from it down onto your cylinders case and case.  Stock Coils often fail after a bike has been hopped up; too much strain on it.

Could be your ignition module, but it seems to me that the bike wouldn't start let alone run properly albeit for a mile or so, if the module crapped out.

Lastly, check behind your ignition switch (not the coil and not the module) where your key inserts.  Make sure those three wires are not only connected to their posts but also securely connected.  I've also experienced that issue where one wire actually was fraying and hanging on by a thread.

Oh yeah, maybe a fifth issue: check to make sure the battery terminals are secure.

thanks James.. its not fuel, and its not the switch (I've linked it out)... I'd say 3 things.... pickup / coil / module. All rest is tight, clean, flowing etc... question is which one.. do you bin the lot and go for the Ultima fix.. or try find it?

[1340evo]

Old trick-
Pack a can of electronics cleaner or anything that gets instantly cold..
When the bike quits,  spray the suspect part, and try starting.
When you cool off the right item it will fire up.

Now.. why didn't I think of that... so obvious... great, thanks... I'll take the covers off (and then it wont do it).. and go for a spin.... thanks

[Mark222]

Buddy had a 1996 Sporty, same issue.  Ignition switch change as all was well.

I was surprised when tracing wires, didn't figure the switch would have been the culprit. 

Mark

[dogger]

Circuit breaker.

[1340evo]

Thanks all.. had the switch in bits and its fine... no breakers in that part of the line......
think it must be electrical breakdown?...

[hanger]

It's in your ignition or coil. If you can get your hands on a spare coil change it or buy one as I don't recall them costing that much. I had the same thing happen to me whenever I ran into rain....coil was bad.

[JamesButler]

Circuit breaker.

Do circuit breakers work intermittently?  I thought they either work or they fail completely 

[1340evo]

It's in your ignition or coil. If you can get your hands on a spare coil change it or buy one as I don't recall them costing that much. I had the same thing happen to me whenever I ran into rain....coil was bad.

I agree.. its typical coil... but its Accel with only 2000 miles on it... though Accel were top quality... used to be.. maybe not these days.... I have a Duna coil... will make so connection post so I can use it with my leads and give it a go!.... Cheers

[thumper 823]

Circuit breaker.

Do circuit breakers work intermittently?  I thought they either work or they fail completely 

Then open if they get hot (short) and close when cooled dwn.

[JamesButler]

Circuit breaker.

Do circuit breakers work intermittently?  I thought they either work or they fail completely 

Then open if they get hot (short) and close when cooled dwn.

Got it.   

[1340evo]

well the Dyna works okay in the garage.. will have to wait until it stops raining to test..... 

[Hossamania]

Going back to fuel, is the vent working properly? Try opening the gas cap if it fails again.
Have you checked for spark when it dies? If it has spark, try shooting some fuel into the carb and restart.

[mr. pitts]

IIRC, you need a coil with the ohms range suitable for your ignition system. A points coil will have a different range to an electronic ignition coil. They will both work initially, but the incorrect coil will overheat & break down & leave you with the symptoms you have. Just work on ONE thing at a time. If you fiddle with half a dozen things at once & it ends up not running, you'll be chasing your tail for ever.