Plug Chop On 4 mill

[norcalrhino]

4 mil engine, flat side 33's, timing +5, race fuel,v-force 3, pingel fuel valve, pod's, 20cc domes, 170 mains (on rich side).... ALL PARTS From Jeff at F.A.S.T.... Carbs sync'd, could only get to 4th pinned with amount of room i had... did twice got the same reading on plug chop...Did leak down after build, passed fine..... this is the reading i get... When sitting on the bike the left cylinder has the dark ring (Rich) and right cylinder has nothing? (Lean) Is it possible theres either a Air Leak? (leak down passed though) or is it possible that one carb needs to be jetted higher than the other??? Please help..Heading out riding in 3 days... Motor rips, no bog, nothing

 

Edited April 24, 2010 by norcalrhino

[TNTS355]

4 mil engine, flat side 33's, timing +5, race fuel,v-force 3, pingel fuel valve, pod's, 20cc domes, 170 mains (on rich side).... ALL PARTS From Jeff at F.A.S.T.... Carbs sync'd, could only get to 4th pinned with amount of room i had... did twice got the same reading on plug chop...Did leak down after build, passed fine..... this is the reading i get... When sitting on the bike the left cylinder has the dark ring (Rich) and right cylinder has nothing? (Lean) Is it possible theres either a Air Leak? (leak down passed though) or is it possible that one carb needs to be jetted higher than the other??? Please help..Heading out riding in 3 days... Motor rips, no bog, nothing

 

 

When you did th leak test did you have your boots on? If so did you take the boots off at anytime?

[norcalrhino]

When you did th leak test did you have your boots on? If so did you take the boots off at anytime?

 

 

yes the billet intake with Boots was on during the leakdown test, and i haven't touched since

Edited April 25, 2010 by norcalrhino

[Snopczynski]

you cant read plugs on a motor that runs full race fuel. The toluene in the gas washes the plug down.

 

You have to jet it on a dyno or by feel.

[norcalrhino]

you cant read plugs on a motor that runs full race fuel. The toluene in the gas washes the plug down.

 

You have to jet it on a dyno or by feel.

 

 

interesting.... why would only one plug show the ring and the other be washed? shouldn't they both be washed down? just Curious

[Snopczynski]

Your getting inconsistent results, that tells me right there the fuel is messing with you. Anything like variance in squish, compression, etc.... can cause a difference in reading between both cylinders as well. Trying to jet off what the plug is tellin you on full race gas is gonna make you crazy, because you wont be close.

[norcalrhino]

Your getting inconsistent results, that tells me right there the fuel is messing with you. Anything like variance in squish, compression, etc.... can cause a difference in reading between both cylinders as well. Trying to jet off what the plug is tellin you on full race gas is gonna make you crazy, because you wont be close.

 

 

Thanks for the info, I'm heading up in elevation so i will be able to knock down the fuel to 50/50 and jet sizes... I'll test and plug chop at that elevation

[sleeper06]

I think stick to one thing,jet for what your running in fuel because diffrent fuel,diffrent jets

[RadarRacing]

i've had race gas mess with me as well. Even had yellow rings not brown. If the plug on the right was a pretty new plug it wont show color sometimes til it's used a mile or two. If you want to switch carbs from one side to the other. Then switch plug wires might have a bad sparkplug boot as well. different things to try.

[papa_smurf49319]

also had race gas throw me for a loop to, at 175 mains i still couldnt get a 2mm smoke ring, also had air leak on right side with no signs of it on the plug.

Me and my buddy were both having the same problems trying to dial it in on the race gas, (110 octane)

 

 

Cody