carbon buildup on plugs

[sketch96]

2013 pro, bpr9eix plugs. new motor with mtn tek drop in kit with head, hps can, legend oil, kurts clutch kit, c3 2.52 ratio.

have about 120 miles on it now and pulled the plugs to have a look as it wasn't pulling the rpm I felt I should be able to pull. Plugs had a lot of carbon on them, small puddle of oil in the Y pipe. I have the oil pump turned up 2 full turns and was running 1 oz oil per gallon fuel premix. I did this same thing with my 2012 and no problems at all. I did have this on the ethanol mode for the first 70 miles approx. as per mtn tek recommendations with the leaner 2013 mapping. It wasn't pulling more than 7900 with 64 gram weights at about 4500-6000ft elevation. with the mods done I was sure I could pull at least 8200.

I am not sure why the plugs have so much carbon on them in such a short time. could running in ethanol mode cause it to run that excessively rich? it ran better in the non ethanol mode but possibly the plugs were already too carboned up to pull more rpm?

starts and idles great. no misfires or anything just wont pull past 7900. any ideas? was gonna blame the clutch kit but seeing the plugs I thought it may be something else.

 

[Frankenytro]

Does your sled still have the oe Polaris cap on the oil res?

 

[Frankenytro]

I am just guessing the Pistons went in with oil during assy, plus I would imagine you heat cycled it a few times (possibly ran the pump at wide open for a bit). Add that to the 2 turns plus possibly a non oe cap and I believe you would have the makings of an extremely oil rich environment..

just thinking out loud

 

[sketch96]

I have the passo vented oil cap. I have talked to a few people about that cap and I did see a big increase in oil usage. That along with pump turned up and oil in the fuel etc etc. I have decided to go back to the stock oil cap after talking to a few people about the one way check valve passo uses in the vent line. Some opinions are that with increased under hood heat the oil tank could build some slight pressure that cant be released and possibly force the oil thru the pump and that could be the increase in oil usage. with the Polaris or the doo cap pressure/vacumn can be released either way when the vent opens. just some different ideas that I have heard. I will put new plugs in and leave the pump turned up and keep mixing some oil in the fuel for the next ride or 2 and see how things go. Then I may try the passo cap again.

 

[Frankenytro]

That is right where I would start too. Report back and let us know if the fouling continues.

 

[sketch96]

Will do!

 

[ken.gee]

For what it's worth sketch, I found the same "oil" residue in my y-pipe (stock 2013 Pro). It matched the goo I found built-up in the exhaust valves as well. I didn't have any carbon build-up on my plugs or noticeable performance decrease, so I'd think that you could probably eliminate that as a cause or symptom!

Sent from my SM-G900W8 using Tapatalk

 

[Frankenytro]

Any 2 stroke will have excess oil pass threw it and out the pipe as long as it isn't being run excessively lean in order to make power. With the growing trend of turning up the pump (and my Pro's are both turned up) or using an aftermarket cap, there is just that much more oil being consumed for the same amount of fuel. Now Just turn up that pump, plus add a free flowing cap, and I think it is close to the same as about 4-5 turns on the pump adjustment. How come nobody is going past the 3 turn mark??? I believe (in my uneducated opinion in this matter) that with the pump turned up, as well as the cap, that the plugs are going to be destined to fail/foul.


How did the sled react to new plugs??


no posts is a good sign usually lol.

 

[gdhillon]

Mine seems to puke oil out of the exhaust if it sits on a deck or in an enclosed for a long time. I have my pump turned up 1.5 turns and a doo cap. Iirc the ratio has to be pretty rich to affect performance?

 

[sketch96]

I have yet to get out for another ride since i put new set of plugs in and the stock oil cap back on. I was in the ethanol mode for about the first 70 miles of riding also. Im now back to the non ethanol mode. Will update when i finally get done with christmas and get out there for a ride!