ST1300 HT Lead Observations

[jfheath]

Removed. (In error by me). But the same info can be found here.

ST1300 Poor Running - HT Leads & Plugs - Solved | ST1300 Related

Describing an issue with poor running on my ST1300. Symptoms were engine seemed to be running fine except with little low end power and a sensation of always riding on a rough surface. Revs had to be kept up in order to set off safely. It turned out to be HT leads and plug caps. Details...

www.st-owners.com

 

[SupraSabre]

That's what I call determination and detective work in finding a problem! Good work there John!

And good advise to all to double check if a problem like that is happening!

 

[Scooter]

Maybe these photos can help. This is the number three wire from a set of spare wires and coils that I picked up on eBay several years ago.

 

[BakerBoy]

John, with marginal contact between coil 'pin' and wire, I'd expect some arcing and heating... did any of the insulation melt? Or was there corroded/blackened conductor wire at the end where it contacts the coil 'pin'?

 

[shands]

Apologies for the bump - but did you discover anything drastically different with your new #3 lead?

Mine (a 2004 plate/A2 model) has got 92k on it now and has long suffered the same symptoms as yours and "feels" like an intermittent cylinder loss. Plugs were changed as part of recent service - no difference. Coils were replaced by me last year to address lumpy behaviour. Slightly better, but not perfect. If I'm honest, I didn't pay attention to the grommet/glue. Fairly certain that each coil socket had a recessed pin.

Anyway, HT lead replacement was my next move. However, after reading your write-up and at ?43 (each!) for the caps and then between ?15-?20 each for the leads from Mother Honda (bringing the total to about ?240 for a complete set!) I'd rather dig a bit more first!

For the #3 coil lead, there are two part numbers: 30733-MCS-G01 and 30733-MCS-G02 (second being the most recent). From what I can gather, A4 models onwards had the -G02 (revised) part as standard. Just wondering what differences you noticed? My main concern is the length of the cable. Sod's law the new one will be a couple of centimetres too short!!

 

[shands]

Wowee! Thanks for the detailed reply - very much appreciated. Thank you.

Surface rust between the frame and coil is a possibility actually. When replacing the coils, I can't recall if I gave the frame contact area a good going over with the wire brush or not. Good suggestion either way..

I've just got off the phone to Hunts Honda in Manchester. The #3 cylinder G01 part number has been discontinued and unavailable for order - which suggests volumes. With the tight fit you describe, it wouldn't surprise me if the replacement is slightly longer with a beefed up grip mechanism. ?14 for a Honda original lead isn't too bad to replace as a matter of course anyway. Lasting 12 years with 90k+ miles is fair going for the original set of leads - common fault or otherwise. I think I'll leave the ?40/each plug caps for now though.

Hopefully I'll get a chance to tear down the bike in the next few days and will post how I get on.

Cheers - I'll buy you a drink!