still fouling plugs after new wiseco top-end

[kawicam125]

hey guys, i just got my top-end rebuilt and its still fouling spark plugs, before and after the new wiseco top-end. before: messed with air screw, needle, pilot jet, main jet, kind of spark plug. the spark plugs weve been running is BR9ES,BR9EG, and one BR9EIK. im riding high rpms in 2nd, mid rpms in 3rd. i have been riding at TNT only ( just the tracks). we have to get a new water pump seal installed because water keeps leaking into the oil. weve also been running 32:1, going to change to 40:1. thanx for any replies.

 

[+30]

I know Im going to get it from the 40:1 crowd, but I think with the new top end you would be better off staying 32:1 on a 125. I wouldnt try to fix a jetting or seal realated problem with cutting the oil back. If your bikes been running with low coolant levels its getting hot. I would want enough oil in the gas to handle it all. After the water leak is fixed, If jetting didnt do anything for the plugs then you may need to pressure check that right side crank seal.

 

[souphmars]

have u checked ur float level? what does ur plug look like?

 

[kawicam125]

after it fouls, its all black and oily( as youd expect). and when it fouls, you can tell. whats the standard PSI for the right side crank seal? if its low, how do you get the compression back ( buying a new one maybe), and will this ( do you think) solve my plug problem?

 

[nikki]

Try a BR8ES - hotter plug. Works well in 125's.

 

[kawicam125]

we used to use those nikki, ive heard that those BR8's are for low-mid rpms or trail riding.

 

[nikki]

Did you foul plugs when you used the BR8ES?

I know several MX'ers who ran 8-heat range plugs in their 125's. Even A riders. As long as you check the plug once in a while, and it's a tan/bronze color, not white-ish, you're fine. Now if you're a desert rider, and riding in 4th-5th gear WFO for extended periods of time, I wouldn't recommend it.

 

[+30]

Have you check float level? If you cant get any luck from jetting/float/airscrew you may want to look at that right side seal. http://www.dirtrider.net/forums3/showthread.php?t=97952
if you build your own tester, measure your exhaust opening and intake just to make sure before buying the pvc and expansion plug everyones bike is different. dont exceed 8psi during your pressure check or you could blow out the seals possibly.

 

[bikercrazy99]

.

if it foils everytime you start it, like get it started then 2 secs it cuts off and foiled, check the ignition system, i had this problem b4 n they put new coils, cdi unit in etc

 

[kawicam125]

we fouled plugs using the BR8's and the BR9's. i dont ride wide open, just 2nd and 3rd gear. were going to put in the water pump seal tonight and possibly new grips. it fouls after about 20-45min. of riding. i really want to fix this problem and soon! +30, we own a compression tester measuring in PSI's. do you just put that in the exhaust and start the bike? ive heard about float level for a long time, but i dont know what your float level is. there is only one other thing i need to say/ask, whether the plug is fouled or not, if i take it out, it'll always be black with oil, fouled or not. and if you look into the cylinder, you can see oil. to explain that( possibly), when i first got this 125, i didnt know about down-shifting and clutching. i used to have a good bit of oil come out of the silencer, but know, since i mastered those two techniques( im only 13y/o), almost no oil will come out of the silencer. do you think that i did something to the bike other than it always fouling plugs? i know that i ride right and im not the one fouling the plugs, ( it's all the engine's fault!). if you guys know can think of anything else or help me with problems already stated, ( right side seal, float level, etc.) i would appreciate it very much! thanx!

 

[ellandoh]

jet the bike

 

[+30]

jetting

http://ericgorr.com/techarticles/carbtuning.html

this like covers almost everything you need to know about jetting, still you will need a service manual try repairmanual.com if you cant get one locally, also double check your fuel oil ratio just to be sure your not chasing your tail.btw (your compression tester should thread into the spark plug hole on the cyl head, kicking the bike over will show peak compression only use a few kicks, there is no oil to lubricate the cyl when doing this.) - that just checks your ring seal anyway, which may not be your problem. You need different jets to experiment with try www.bikebandit.com go to oem parts finder, and look for smaller numbers for leaner jets and vice-versa.

 

[kawicam125]

nice read +30. were probably going to check the float level (know that i know what it is) and the right side crank seal. but dont stop posting replies, this thread isnt done until this problem is solved.

 

[1994WR250Chad]

http://dirtrider.net/forums3/showthread.php?t=133064

Jetting Thread... it may help... enjoy!