Ignition Coil Refurbishment Possible? Fuel/Ignition Issue

[dkenn]

Hey y'all,

Finally got my bike up and running and pretty much finished last month and she was riding good for a while then I started having fuel and idling problems---so unique i know. I ended up cleaning the tank rust out and carbs completely and cleared out the jets. The bike then ran decent after that, but now won't sustain an idle again with or without choke. The spark plugs get flooded/fouled easily it seems. Idle screw adjusted correctly. Float bowls good. Etc etc. The left muffler has a weaker pressure coming out of it when compared to the right muffler.

TLDR: found out my ignition coils, spark plug caps, and the cable in between them are all corroded on the left side. The right side coil is a bit rusted at where the cable screws in. On the left cap, the multimeter reads 30 ohms, compared with the supposed 5 ohms.

Two questions:

1. Do you think my "fuel" problem is really an ignition problem due to the corrosion in the spark plug cap and ignition coil? Would a weak spark cause a struggle to idle?
2. If this is the case (or maybe I should anyway) can I refurbish my ignition coils well enough to avoid buying new ones? See attached images.

 

[dkenn]

Okay. I finally got her in a good place to idle with the carbs. But i guess the question now is — do I save the ignition coil replacement/refurb for winter? Lol

 

[CaptChrome]

the question now is — do I save the ignition coil replacement/refurb for winter?

Cleaning the coils up, testing them and replacing the high tension leads is a one hour project, two if you use it as an excuse to be in the shop drinking a beer or two. Why wait?

 

[dkenn]

Can't argue with that! Thank you

 

[Peter B]

I have had a recent experience of being convinced the coils on my 1981 XS400SE (which has been modified to cafe racer) were causing me misfiring issues. Initially I believed it was CV carbs with Airpods giving too much air. Then I found the LH cylinder (which was the intermittently firing cylinder) carburetor diaphragm had a small hole. I had pretty much decided at that point to put flat side Mikuni's on the bike so I went ahead and did that expecting a plug and play performance improvement. Alas LH cylinder still skipped beats. Swapped coils over still issues but not consistently tracking cylinders and coils...properly confused I spoke to a bike mechanic (48 years in the trade) and said I suspected both 44 year old original coils were creating issues. He responded "48 years in the trade and I've only known three motorcycle coils to fail - much more common with car coils" and went on to say "I would suspect your electronic ignition or a wiring problem from it to the coils". I have Newtronic electronic ignition so I spoke to their customer support folk who explained light sequence etc and mine appeared good they too suspected dodgy wiring issue. So too late I started getting more intimate with the wiring and lo and behold there was a poor connection on the red white wire i.e. the common link wire to both coils. Remade connection and now seemingly discovering the Mikuni Flatsides really are plug and play. Excellent and yes the 44 year old coils seem fine. Apologies this is somewhat long winded but I clearly made a schoolboy error of not thoroughly checking the wiring was all solid before blaming the diaphragm / coils ect. If reading this far helps someone to avoid making the same "rookie" mistake its been worth the few minutes it's taken me to jot it down....

It would be remiss of me not to also heap praise upon "Yambits Limited" here in the UK who refunded me for the two coils I purchased within their 28 return policy. A copy / link to their website below.

https://yambits.co.uk/parts_for_yamaha_xs400se.html

 

[kebabs]

Hey y'all,

Finally got my bike up and running and pretty much finished last month and she was riding good for a while then I started having fuel and idling problems---so unique i know. I ended up cleaning the tank rust out and carbs completely and cleared out the jets. The bike then ran decent after that, but now won't sustain an idle again with or without choke. The spark plugs get flooded/fouled easily it seems. Idle screw adjusted correctly. Float bowls good. Etc etc. The left muffler has a weaker pressure coming out of it when compared to the right muffler.

TLDR: found out my ignition coils, spark plug caps, and the cable in between them are all corroded on the left side. The right side coil is a bit rusted at where the cable screws in. On the left cap, the multimeter reads 30 ohms, compared with the supposed 5 ohms.

Two questions:

1. Do you think my "fuel" problem is really an ignition problem due to the corrosion in the spark plug cap and ignition coil? Would a weak spark cause a struggle to idle?
2. If this is the case (or maybe I should anyway) can I refurbish my ignition coils well enough to avoid buying new ones? See attached images.

View attachment 38793View attachment 38794View attachment 38791View attachment 38792

change the coils.i had the same issue.