Weak Spark

[Witterings]

Has anybody had any issues with a weak spark or are they just like that in comparison to other bikes?

If not, wondering what it may be, the stator's 1993 so maybe could do with a refurb, new coil or possibly the bike was stripped and powder coated by the previous owner, I wonder if maybe he's not made a great ground connection onto the frame.

If anbody esle has ever suffered the same be interested to hear what it was and the what cured it or maybe these just don't give a big spark?

[Gammakeith]

They do look a little weak but that doesn't really mean much. A big fat spark that doesn't cope with combustion pressures is no use. If some engines with magnetos are not used for a long time the magnetism in the rotor can start to fade away. However, it should reenergise itself if used regularly. Does yours start OK (ish) and run without misfire? If so, I wouldn't worry.

Keith

[Witterings]

They do look a little weak but that doesn't really mean much. A big fat spark that doesn't cope with combustion pressures is no use. If some engines with magnetos are not used for a long time the magnetism in the rotor can start to fade away. However, it should reenergise itself if used regularly. Does yours start OK (ish) and run without misfire? If so, I wouldn't worry.

Keith

It's certainly getting to start easier (was awful at 1st), it sat for a long time with very little / no use while the previous owner refurbed it and then he didn't use it for ages after he'd done it.

It came with a heap of other minor ish issues which have been resolved, it was running as rough as but overall has improved and the starting has got a lot better but the guy that looked at it for me said the plug's still getting pretty gunked up which can be a symptom with what appears to be a low ish spark.

Maybe I'll just run it some more and see what happens, it's also blowing a load of thick oily crud from where the front / rear exhaust pipes meet ... I stuck that in a facebook forum and a few people said that can be caused by it sitting idle for a long time, take it out ride it like I stole it and it should clear.

[Gammakeith]

Yes, you need it well blown out before you can really read the plug. You need to clear the crankcases of residual oil after a rebuild and it sounds like that is starting to happen. A misfire would have to be pretty bad to gunk up a plug. Have you confirmed you have the correct plug fitted? Its worth being aware there are a lot of fake NGK plugs circulating and they can cause problems. Also, have you checked your oil pump adjustment?

Good luck!

Keith

[Witterings]

Yes, you need it well blown out before you can really read the plug. You need to clear the crankcases of residual oil after a rebuild and it sounds like that is starting to happen. A misfire would have to be pretty bad to gunk up a plug. Have you confirmed you have the correct plug fitted? Its worth being aware there are a lot of fake NGK plugs circulating and they can cause problems. Also, have you checked your oil pump adjustment?

Good luck!

Keith

Thank you again ..... I just bought the plug from Halfords and I guess everything they sell should be genuine and yes have checked the oil pump adjustment as well, it was marginally off (maybe die to new cable) but only a tiny amount and is now corrected.

By chance do you happen to know how much 2 stroke oil they actually hold (Itried googling it and couldn't find anything), I believe there's still a lot left in there after it's dropped below the level of the indicator and in which case that's only really useful for telling you when you're close to getting full as opposed to needing a top up.