Gas In Oil, WHAT!

[82CSMiata]

Okay, just rebuilt top end of 400ex, Timing chain tensioner broke causing 4 bent valves. Rebuild consisted of Timing chain tensioner, timing chain from 450R, over sized intake and standard exhaust valves with three angle valve job, new valve stem seals, new rings, and new gaskets everywhere one was removed. Been putt'en around on it for a few hours off and on, loaded it up once by lifting front then rear. I checked the oil in it and it was full to the max, very thin and had a gassy smell to it. Any ideas on what is going on. I drained and refilled with fresh oil, hope this was a one time occurence. My 400ex has a K&N filter, 11:1 wiseco piston, Stage 2 Hotcam, new valves, no choke in stock carb, 42 pilot jet, can't remember main jet, on third needle ring, Fmf powerbomb header, Fmf powercore 4 muffler, and new stuff previously listed. Did not smoke at all before rebuild, does not smoke at all now, but has always had trouble idling. If you set the idle after 5 mins running, it will be way to high 45 minutes later. it also back fires a bit at idle and on deceleration while in gear. I am also in Louisiana with 80 degree weather. Any input is grateful, on any of my problems. it also has a new sparkplug.

[rooster300ex]

I notice that when I run 10-40 honda oil in my quad. Its real thin and smells gassy. I think its normal. I run 20-50 in the spring & summer and notice its not as thin,but still has a smell to it. I've never had any problems with the motor.

[Wheelie]

Sounds like the needle valve in the carb isn't seating properly.

[mr._bowtie]

If your getting gas in the oil then its washing past the rings, which isnt good. but first things first. I would take the carb apart and try a #40 pilot, sounds to me with all the idle trouble and low end problems that you are running way to rich down low. Does it want to cut out at low rpm everyonce in a while? And is the inside of your pipe all suited up and black? Id clean the needle and seat up and make sure its seating properly. If that dosent fix it then sounds to me like its time for rings.

[HPIcamaross]

I had the same problem when i changed my oil...it was so strong that is how i noticed. I know my carb isnt that great either cause when its cold it wont star running...should i get a whole new carb or just rebuild it?

[82CSMiata]

I just put new rings in it, so I guess they are possibly not seating, but the carb has been sitting unused for about 6 months so I will put the 40 pilot back in it and clean it good and go to 20/50 oil. Man I hope that works, I know I put the rings in correctly. Does anyone know what size gap should be for a stage 2 hotcam, I set it to .004 I and .005 E. But those are stock settings. :ermm:

[mr._bowtie]

By gap I am assuming that you mean your valve lash, or the space between the rocker and valve. If so then you did the right thing. The last cam I setup was a Web cam, biggest one you could get without modifying valve guides and so on. I was told to set that to stock lash numbers.

[daman02]

The #1 cause for gas in the oil is that the fuel valve in the carburetor is not shutting off and it is overflowing with fuel and it is flowin down the intake into the valves then down into the oil. I bet if you look at your air filter box you might have a little bit of gas in there to. If this is the cause pull the carb off and have it soaked and cleaned.