Fouling a Plug after one Ride?

[Cleric]

Hey guys im new to this forum and new to working on jetting. Now i know theres a lot of posts about jetting but honestly i know nothing about what the numbers mean or what to turn in or out on the carb. All i can see on the side is the choke which you can turn either way and one brass screw which i think is the idle screw but again im not sure.So if some of your smart guys could help me out it would be greatly apreciated.

Heres whats happening. I bought a brand new plug and went riding here in arizona and within about 1 1/2 of riding not slow or putting around we came in and ate lunch.She was running perfectly fine no problems but After lunch (10 mins) she fired up but after riding about 100 yard away from the truck i hit second and she just died. Took the plug out cleaned it with a wire brush and she started again but died within 30 seconds. I brought it home and did the same thing with cleaning the plug and same this happened. The plug was brand new and the center of it was light grey when i took it out. No big deposits or anything. I dont want to keep going through plugs cause its getting expensive so i need your help.

What are your guys 2 cents?

Thanks

Cleric

 

[The_STiLe]

that brass screw is the air srew, from memory the idle screw is the one with the locking nut

 

[Cleric]

ok thanks. does anyone know what it would be stock? cause i dont have my manual yet and dont know what stock setting on it would be for my 98 yz250

 

[fretslider51]

Sounds like you are running lean from your spark plug description. The dying could be some other things too. I would say to check your air filter, but if that was dirty you would have carbon all over your plug. Once you get your manual make sure you have the right plug as well.

 

[Cleric]

well what do you think i should do with the air screw?Would that do anything? I was wondering cause i dont have the money for a manual and it will be about a month till i can get one. My filter is clean cause i just cleaned it. And i got the right plug cause i looked it up and confirmed it with the books at a local MX store.


Any other suggestions are welcome.

Thanks

 

[Nathan Rubin]

Fouling plug.

Hi dude.
How dude you do? :laugh:
Before you tweak anything, try o understand that is carburetion and how it works.
Anyway start the engine with clean plug; keep it working for 10 minutes then screw it out; take pictures and send me.
[email protected]
I will do my best to help you dude.
KR
:cool:

 

[Cleric]

ok i will do that but will adjusting the air screw help any?


Will it help the Idle cause right now my bike will not just sit and idle on its own. If i let go of the throttle it will just die.

What can i do to fix that?

Thanks

 

[Cleric]

anyone else have any ideas?

i think the plug might be getting messed up due to oil? you think 32:1 is to rich for here in AZ?