250r jetting?

[ZRider400]

My friend has an 86' 250r .....the only motor mods it has is a bills pipe, fmf powercore silencer, uni filter, and a mikuni tmx carb......


does anyone know what jetting to run with them mods?..... we are leaving the lid on. right now it has a 400 main jet and seems really rich.

heres a pic of the R

[ZRider400]

another pic:)

[spliffy]

a 400 main jet??? I don't even know if they go that high. Check it again.

[R-Crazy]

i know mikuni is a little diff that keihn(sp?), but it is still in the same range (100-250 about for normal bikes). 400 would have a HUGE hole
i would guess a 175 and work ur way down. the do ur needle and then the crew and the pilot

dave

[spliffy]

I didn't see that it was a mikuni carb in your first post. I Have Mikunis In My Sleds & They Run Around 300's For Mains, So I suppose it could be 400.. but I think that is way to high still.

[ZRider400]

ok thanks for the info....

[powerslider]

Try this;
25 pilot
needle 2nd groove from top
380 main

[ZRider400]

Originally posted by powerslider
Try this;
25 pilot
needle 2nd groove from top
380 main

ok will try tomorrow:)

[ZRider400]

ok i did the jetting you said, it was perfect! did plug chops and it showed brown every time.

then after a while of riding we started it....it gave its self wide open by its self..........hit the kill switch, still didnt shut off.......... then we were like OMFG WTF so we like pulled the plug cap off the plug so it dont get spark....still didnt shut off!!!!:huh then we pulled teh fuel line off still didtn shut off.......then after like 2 min of idlin wide open it finally shut off...i think it blew lmao.... o well not my quad .:p

[powerslider]

OUCH!! Sorry to hear that, did it run out of fuel? You should have tried to switch to reserve or it may have developed an air leak. Check the compression to see if it's smoked or not.

[ZRider400]

ya im pretty sure it ran out of fuel.......once we pulled the fuel line off, it was just burning up what was left in the bowl of the carb..... i dunno what to adjust/check before i start it again...... because i dont want that happening again:ermm:

is it possible for a motor to run with the spark plug cap off the plug , and kill switch off???????? wierdest thing i have ever seen!:huh

[powerslider]

Yes they will do that, it gets so lean that the heat generated is hot enough to ignite the fuel and it will rev to the moon. I'm afraid it's got internal damage but check the compression first, 150# minimum.

[ZRider400]

o and what plug should it have in it?........ it has like a br6es or something right now. isnt that a tad toohot of a plug?

[powerslider]

Yeah cripe throw that plug away, BR8ES, B8ES, BR9ES,B9ES any of those will work fine.

[ZRider400]

ok thanks for the info...... its so wierd what happened...it was running awesome, then all of a sudden it like falls appart lmao...... o well

[powerslider]

OK, Good luck with it.....

[Bean]

think maybe that plug coulda heated up the head to ignite the gas?

[powerslider]

It sure didn't help matters any...

[ZRider400]

the person that had it before my friend obviously didnt know what plug to run in it:( o well.....we will check compression , and get the right plug. hopefully for his sake (his first quad....) its not messed up too bad.