Poor starting - bogging down - coil problem?

[Lump]

Looking at the vehicles in my signature and the issues in the topic - you'd probably assume this is the Jag playing up but no its the trusty old Honda GL400 (basically a CX500),

 

Basically the issue is it will start and run fine when its sunny and it will start and run fine when its raining but if the weathers in between, misty or overcast or starting to blow up into a storm I just get a whole heap of cranking with little ignition.

 

If I can get it to fire up it requires a lot of throttle to keep it running and it won't rev past about 5k. It can be driven like this but it needs full throttle and a lot of riding the clutch to get it moving and it ain't quick - sometimes it will snap back to running correctly but not always.

 

I have had ignition problems in the past with this bike - the following parts have been recently replace - plug leads, spark plugs, ignition switch, ignitor boxes (these tell the coils when to spark). In an effort to help with this issue I've cleaned up the kill switch and re-taped the ignition leads but it desn't seem to have made a difference

 

I have tested the system using the info in the following link when its running and everything seems fine - this bike has the transistor ignition 

http://www.genebitsystems.com/david/MotorcycleElectrical/IgnitionProblems.htm

- although the spark appeared to be pretty weak and the plugs a bit fouled.

 

Could this be a coil issue? - I've heard of them stopping running after a few minutes but never like this - an old mechanic once told me they ran better during a Norwester does that mean they could stop working enough to effect the bike in other conditions?

[Willdat?]

I hate spark issues - no opinion on what's happening, but remember the stator/magneto is another possible source of your issue.

[h4nd]

My Daihatsu started more and more poorly at one time, and I replaced lots of bits. The actual problem was indeed the coil. It had started "tracking" from the tip (HV output) down to the case of the coil. I tried cleaning it, but no go. I replaced it (check for proper type, ballasted / vs not), and it solved immediately.

 

I've heard they can break down internally, though I've not seen it.

 

Avoid running the ignition without a spark plug connected, which will cause over-voltage, and may cause insulation breakdown.

 

You should get a good fat strong spark from that kind of system. What's the battery voltage? Kick start or electric starter?

[Lord Gruntfuttock]

Checked your earths...?

I always have dedicated solid earthing points on any bike build, cos it sucks replacing parts to fix a problem caused by poor ground connection...

[RevDWC]

Just going from memory here, but some earlier CXs have high and low speed ignition ciruits. Sounds like one is failing.

Not sure if the Ignitec units are still around, likely superseded by now, but is fully tunable after market system. Wasn't cheap, and earlier bikes require bodging or later spec stator.

[Lump]

 

 

 

You should get a good fat strong spark from that kind of system. What's the battery voltage? Kick start or electric starter?

 

ah the mythical fat blue spark, battery is well charged  12.8V from memory - drops to around 11.5 when cranking - Bike has an Electric starter

 

 

Checked your earths...?
I always have dedicated solid earthing points on any bike build, cos it sucks replacing parts to fix a problem caused by poor ground connection...

RevDWC, on 14 Mar 2016 - 8:57 PM, said:

 

Earth is just under the seat it looked pretty good already and I had given it a good clean up as part of the other fixes but it doesn't seem to have helped.

 

 

Just going from memory here, but some earlier CXs have high and low speed ignition ciruits. Sounds like one is failing.
Not sure if the Ignitec units are still around, likely superseded by now, but is fully tunable after market system. Wasn't cheap, and earlier bikes require bodging or later spec stator.

 

 

I hate spark issues - no opinion on what's happening, but remember the stator/magneto is another possible source of your issue.

 

 

I think those are the earlier CDI ignitions (mine has the TI system which is 'apparently more reliable') I have discounted the stator as a possible issue as the charging system seems to run well when the bike is running.

 

 

Its starting to look like I should try swapping the coils out to see if this fixes things - can anyone recommend somewhere to buy aftermarket coils for bikes?

 

[kicker]

I have used Dyna coils on a few bikes, I usually get them from ebay

[h4nd]

 

ah the mythical fat blue spark, battery is well charged  12.8V from memory - drops to around 11.5 when cranking - Bike has an Electric starter

 

 

Should be tons unless it's a strange ignition system. Dai alt wore through its brushes earlier in the week. Ran fine for 2 days on total loss, down to a battery V of ~8V. It's kettering  ignition, with no starter / ballast system.

 

Again, make sure you get the right kind of ignition coil, ballast Vs non. I suspect electronic ignition systems may be more fussy in that regard. If you're still having troubles with correct coil, bring it round, I'll have a looksie.

[Lump]

Cheers for the pointers guys, I've found some possible replacements but I've left the coils at the auto sparky's to be fully tested before I order them

[Lump]

Coils tested as being fine.

Thought maybe the plugs were fouling makng it difficult to restart - I tightened up a few of the intake clamps which got the plugs reading nice and clean and took it for a decent ride to recharge the battery and everything looked good - but then it nearly left me stranded in town not firing properly - though I managed to baby it home.

 

- Ive had a look at the battery with a hydrometer tester and it looks like I've got a bad cell. The ignition systems in these bikes win't run without a battery and a dud one will cause all sorts of problems(apparently) - I'll look into replacing this and see if it helps

[Lump]

Finally traced this problem down - a lot of people had suggest bad ground so I thought I'd double check that but they all turned out good.

 

I was then thinking about running a 12v source to bypass the ignition switch - kill switch etc in case any wiring was shorting out in that area - I was trying to work out where to run the power to and I thought I'd just check the resistance from the positive battery lead (the battery was out being recharged at the time) to the 12v wires that lead to the coils.

 

Everything read as expected but then I noticed that the resistance shot up if I moved the positive battery lead around - up down left right etc. I removed the lead (which lead to the starter solenoid) and all the braided metal is breaking down at the starter solenoid end (weirdly the starter has never given any issues) the 12v lead to the rest of the loom branches off where the main positive lead attaches to the starter solenoid. 

 

Knowing that the starter motor is still getting enough juice somehow I took the lead for the rest of the loom and attached it straight to the battery positive terminal and goodbye ignition troubles - she's been running fine for three days now! Theres a few pics of the lead below the smaller red wire was leading the the main fuse / rest of the loom before I bypassed it.

 

So all in all it kind of was a bad ground - only on the other side of the battery - I'm a new lead made up for it and hopefully she keeps on trucking as its been pretty bloody irritating getting to the bottom of this problem.