So after I ride and let the bike sit I notice black goop coming from exhaust, where expansion chamber attaches to cylinder. What generally causes this?
Black goop
- Thread starter Fast6hand
- Start date
Hope it's not the seal I just rebuilt a month ago. I thought it might be running rich. I haven't plug chopped yet, I just got through 2 full tanks. I'm running a #330 main. I'm sure it's rich.
Sometimes, this is a sign of over-revving the engine. The return wave doesn't meet the exhaust port before the piston closes it off and the mixture will stay in the pipe, soaking the packing after a little while.
In this case I don't think it's the that, only because I've only ran it at 3/4 throttle and below.(on the needle)for break in period. I'm gonna be pulling exhaust and leak testing anyways. I just ordered crush washers for exhaust. I can inspect more at that point.
- oil block off
- 32:1
- LRD chamber and silencer
- CFM airbox/uni pod filter
- .20 over/ wiseco pro-lite
- lightened flywheel
- boyseen pro series reeds
Yeah, that would make the 330 way too big. 290-300 is what I'd run. I'd call that your problem.
How do you like the lightened flywheel?
How do you like the lightened flywheel?
When mine did it, it was because it was running way too rich. I backed down the main jet. Pull the plug. If its soaked and black, its running rich
Id say the 290-300 is still likely too big, I have a LRD adjustable an TRENGA silencer, with aggressive trail ported cylinder, head mod, boyesen pro series reeds, lightened flywheel, stock box no lid an a uni, 68mm bore an 32.1, an im running a 280 main an one size smaller pilot which LRD recommends an clip in middle, a/s 1.75 out, my plugs look great maybe even a light touch rich like half a main size, it like mocha colored, an no carbon build up at all, I just rebuilt the bottom end this weekend, cause crank was getting loose, an the top of piston looked perfect nice light soot layer you could rub off with a rag, thats after about 80hrs of use without being apart
It is pretty normal for a header pipe that is held on by springs to ooze spooge.
Providing there is an airtight seal at the cylinder, live with it.
A #290 main would seem to be a good choice.
The #330 main would not be the reason for the black spooge as below 3/4 throttle the jet would not have been operating and not adding any extra fuel to the mix.
You could have a #500 main jet in there, but at 3/4 throttle the needle jet will control the amount of flow and still not run too rich.
A black, wet plug is not really a good indication of a rich mixture on the needle or main, it could be an indication that the idle is set incorrectly.
The way to find out if the AFR is correct is to do a plug chop.
Providing there is an airtight seal at the cylinder, live with it.
A #290 main would seem to be a good choice.
The #330 main would not be the reason for the black spooge as below 3/4 throttle the jet would not have been operating and not adding any extra fuel to the mix.
You could have a #500 main jet in there, but at 3/4 throttle the needle jet will control the amount of flow and still not run too rich.
A black, wet plug is not really a good indication of a rich mixture on the needle or main, it could be an indication that the idle is set incorrectly.
The way to find out if the AFR is correct is to do a plug chop.
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Well I'm gonna be plug chopping this weekend coming up. The smallest main I have is a #310. So I may be stopping there. I'll see if I can get the smaller mains by then, a 300,290. My air screw is within spec and my needle is in the middle. It actually runs great up to 3/4 throttle. I will report back with findings.
After my rebuild, I also had a spooge leak, it actually blew it all over and took some time to clean up.
Replaced exhaust gasket and problem solved! I dont even get any leakage from the slip on/spring clamp.
I think the small gap on the slipon coupling wouls anyway carbon up quickly and seal the leak, unless it gets disturbed.
I have absolutely no leaks on the exhaust side, and dont have to bother cleaning up the goop...
Now cleaning up the mud, after a fun ride, thats another story...
Replaced exhaust gasket and problem solved! I dont even get any leakage from the slip on/spring clamp.
I think the small gap on the slipon coupling wouls anyway carbon up quickly and seal the leak, unless it gets disturbed.
I have absolutely no leaks on the exhaust side, and dont have to bother cleaning up the goop...
Now cleaning up the mud, after a fun ride, thats another story...
Are you running a 30 pilot? And is the non adjustable LRD the same? Curious because I can't seem to get the a/s perfect with the 32.5.
Yes im running a 30 pilot, which is recommended by LRD, Idk if the adjustable is the same but i would assume they are, the pipe is designed identically, besides being able to change the length of the expansion chamber, which is only to custom taylor the powerband to your style an machine,
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