2-Stroke fouling right cyl. plug.

[Jfishsolevibe]

Yo yo yo!

So the GT380 keeps fouling up the plug in the right cylinder - Obviously I need to adjust my carbs and oil pump, but any advice from the smoke riders up in here?

Its just my right cylinder - All my throttles are synced up - carbs are tuned to the same spec as eachother... Bad injector oil?

Thanks as always dudes!

p.s. - Is this something I can expect to experience frequently due to stop and go city driving?

J

 

[crazypj]

need to check 'wet' side seal, behind primary drive gear.

PJ

 

[chrisf]

And the timing on the bad side

--Chris

 

[Jfishsolevibe]

Thanks guys - gonna get to it now!

 

[boingk]

You could also simply have a dud plug - swap with one known to be good and see if it still fouls. If it does, then check all the more fiddly stuff.

Cheers - boingk

 

[Jfishsolevibe]

So I noted that my right headpipe was a bit loose and had a leak at the manifold. There was some oil/fuell leaking out - and at idle, confirmed an exhaust leak. I tightened it up but havent ridden much since - Could this have been causing that wet plug? Incomplete burn?

 

[crazypj]

no.
could be points or condensers but, it's probably seal

 

[Jfishsolevibe]

Cool - thanks PJ - it's Gas fouling so I'm inclined to believe it's not the seal. Spark issue then?

Thanks again guys!

 

[interceptor]

Just a thought here, but have you checked compression? You say city riding? Stop and go? I don't think city riding is good for a 2 stroke. May need to rebuild top end? But I'm no expert...
And then I just thought: Why would there be gas coming out of your exhaust leak? Personally, I think it could tie in with the low compression somehow. JMHO ???

 

[Jfishsolevibe]

Thanks interceptor! Compression is good - a little lower than spec but good through all cylinders. The plug is gas fouled - indicating a rich mixture or incomplete burn. I'm sure I could benefit from a top end, but as PJ said, a seal in the bottom end may be bad. I'm going to clean the points, check the rest of the ignition system and timing. I'll doublecheck compression, but it seems like it's a spark thing since the plugs aren't oil fouled...

PJ - what am I in for if I need to replace that seal? :-[

 

[crazypj]

I havent done one since 1985~86 but I think its pretty easy.
Pull clutch cover, pull primary drive gear, couple of wood screws through seal, pull it out, press new seal in place.
I don't think you have to do full engine strip on that particular motor?
Get seal first then you'll know
I did a bunch of different bikes, Suzuki, Yamaha, singles, twins, three's, etc tends to blur into just another bike

 

[Jfishsolevibe]

Haha! Thanks PJ! Youre the man!

Ill give it a look - Tonight I tried something very simple that I hadnt thought hard on until after a good push of the bike back to my house after it lost power - I put it on the charge for awhile and seem to be getting much better results. I filed the points as well, so I should be getting optimal spark at this point - Gonna check out the seal tomorrow.

Thanks again!

 

[chrisf]

I still think it's the timing--probably due to the points. That is the first thing I would replace. I fouled plugs a bit whilst I was tuning. Since switching to an electronic ignition, no trouble at all. I would also consider swapping out the stock coils with at least those from MikesXS.

Regarding the seal, you have to yank the motor and split the cases on the RD.

--Chris

 

[crazypj]

Yeah, RD250/350 kinda sucks to do seals. (and transmission )
Generators tend to 'stick' on crank, you have to pull them because one bolt on backplate is on bottom and two on top half of case (or maybe other way round, I forget)