how do you foul a plug in 30 minutes?

[PureMetalKorey]

for all of you reading my last thread, i've had a heck of a time getting my 83 trimoto 175 running right, i replaced the plug and put a fresh tank of gas with a good mixture in and it seemed to be running fine. I rode it for about 30 minutes and put it back in my buddy's garage, went and picked it up today and went to start it and....NOTHING.
same thing as before, it would run off of a shot of starter fluid then die. so i took the plug out to take a look at it, and it was just as black as the last one i took out. so how do you foul out a plug in 30 minutes of riding, and what would cause it?

[cr480r]

Poor jetting

[SYKO]

well.... my old air fooler 300 fouled plugs after about 30-50 mins of riding, even solid on the gas riding, and the plug wasnt all sooted up either, what may have been the problem is that half my piston was missin! You can do a search to find out more about my poor air fooler. Really every 30-50 mins of rid time would equal a fouled plug, and I fooled with the jetting and had it spotless.

[PureMetalKorey]

yeah, i just put a brand new piston in there, i'm afraid it might be a mechanical problem. hope i don't blow another piston.

[NINJA]

Sounds like what is going on is a jetting issue for sure. Your plug is getting carbon fouled while you ride. The engine continues to run because you have a stronger spark at higher rpms. When you shut the motor off and try to restart it the next day it won't start because you can't kick it over fast enough to generate a hot enough spark to burn through the carbon on the electrode.

[PureMetalKorey]

what would you all suggest i do? would moving my needle up or down help any?

[pickleweasel_00]

Try this out

http://www.3wheelerworldforums.com/s...t=carb+jetting

[cr480r]

Is the air filter dirty? Any rat nests hiding in the air intake? Does your bike have a oil injection system? or do you pre-mix your fuel? Does the choke shut off properly?

[PureMetalKorey]

new air filter, no rat nests, oil injection system is blocked off, i premix 40:1 chock is broken so the plunger is just in there engaged all the way.
i heard if you've recently bored out an engine that it's common to go through lots and lots of spark plugs at first?

[Billy Golightly]

Not really. If the airfilter is clean, the carb is internally clean (IE, no orifices or jets are clogged), and the pipe isn't full of trash, then your gonna have to look at your carb jetting (Check the sticky) and if you can't get it after tuning the carb your looking at a possible crank seal (Are you losing trans fluid too?)

[XL-erate]

Could it be your ring expanders? There's various types requiring correct installation and if you happen to get it wrong it causes problems. Also ring gaps have to be staggered around bore. Reason I ask is I recently followed my normal install method on expanders only to find out the particular engine was an exception to the rule, naturally.....

Here's one Wiseco example, but may be different from yours:

http://www.wiseco.com/PDFs/Manuals/TabbedOilRail.pdf

[TeamGeek6]

Verify the fuel level in the carb before wasting weeks on jetting. I screwed with my PJ for months till I figured out the float needle was leaking.

[DeePa]

does this trike have oil injection?

[PureMetalKorey]

if these particular oil rings are required would they be in the box with the new piston? i think i compared pistons and they were identicle i made sure i read directions a few times before i installed it.

DeePa, yes i have oil injection but i have disconnected and blocked the fittings and i premix my fuel.

[InPiEcEs]

Most 2 stroke pistons have 2 rings, both compression rings. Some only had one ring.
You might check your float level, and take a good look at your inlet needle as TeamGeek6 said. If your float is set too high it will cause the engine to run rich, even though the jetting is right. Check those 2 things before condemning the jetting.
Another thing.....be absolutely sure that the choke is not letting fuel into the engine, and remember that the choke plunger seal can go bad, too.
Also......how is the compression?