xkevenx

Member
Dec 4, 2007
95
0
hi everyone, i am rebuilding my friends rm 250 from 1986 and it wont start! it has been ridden one time 2 months ago and when i want to start it now it spews out feul! now the spark plug works, the carb is clean and OK, and he has some very good compression, now after taking off the cilinder and stuff there was some black fluid in the crankshaft tranny i think its oil with a little bit of fuel in it. it isnt oil from the gearbox or water from the cooling system. just oil from the feul; the engine has flooded a time ago and i think its that feul from when it was flooded. could it be that the feul was evaporated and the oil just sank to the bottom of the engine? i have checked everyting in the carb and everything is fine now do i need to drain that feul from the crankshaft? and could it be fine after that? i am out of ideas... everything works fine exept that it spews out that black substance... realy weird
 

Jeromeo

Member
Feb 26, 2007
187
0
Tranny oil turns black right away after riding so I don't think that's a problem. Have you drained the fuel and put fresh premium in? How well did you clean the carb??? And is the air filter clean??
 

xkevenx

Member
Dec 4, 2007
95
0
everything is clean and the fuel is new with oil in it... i have opened up everything and cleand it very well its a freggin mistery... maybe its the timing of the ignition? but i realy doubt it the engine fired up about 3 seconds after putting some alcohol in the cilinder to try it out, it works but its defenetly a feul problem it seems to be flooding but i dont know how, the floats work fine and it has everything it needs to have.. i have experiance with mx bikes and riding so i dont know how the hell it keeps flooding... but there was a bunch of feul in the tranny so that seems to be the freggin problem i just dont know it drives me crazy!
 

magneto

Member
Nov 14, 2001
179
0
If you think there is fuel pooling in the crankcase, perform the following:
1. Turn off gas at petcock.
2. Remove spark plug.
3. Put bike in gear.
4. Turn entire motorcycle upside down.
5. Turn rear tire which will in turn spin engine and blow excess fuel out of engine. (be careful not to cause any sparks or you may burn down Belgium!)
6. Flip bike back upright.
7. Clean plug (a propane torch works well to burn off oil and gas.)
8. Re-install plug and crank bike.

Don't forget to turn off gas when you cut the motorcycle off!
If your bike keeps flooding I'll bet that you either have a bad float, float needle, misadjustment of the two pieces or possibly trash in the gas holding the valve open.


If you are getting gas into the transmission area, disregard everything I listed above.
 

xkevenx

Member
Dec 4, 2007
95
0
i have done everything and checked everything, the floats work fine and the bike still wont fire up! and there is no gas in the transmission tranny so i realy dont know... but when i blow on the boot where your carb needs to fit with the reeds in i can blow and suck air into it... maybe its the reeds but they are closed and stuff... i think a air leak is cousing my problem. im checking it out right now.

and thanks for the advice magneto!
 

magneto

Member
Nov 14, 2001
179
0
You shouldn't be able to suck air back through the reed block toward the carburetor if the reeds are good. Damaged reeds will make an engine hard to start. Pull the reed block and inspect...

You can always tow the bike to see if it will start... :nod:
 

xkevenx

Member
Dec 4, 2007
95
0
it ran today, i rode it in the garden, i needed to kick my ass off and when i janked the throtle it started now it ran good, but when it stalled i could'nt restart it, now it works thats a relief. and aperantly its a 500! now i know why i cant kick it like my old 250 :p
i am going to do some research tommorow, not today i am sick of it :p:p
 
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