1991 Honda CR250R

[Nappy]

Hi Guys,

I am new to this group and hope someone can help me. I bought a used
1991 Honda CR250 off of e-bay. I was under the impression that the bike
ran good, but it doesn't. I have a really hard time getting the bike to
crank. It wil only crank if I spray so carb. cleaner in the cylinder.
When it does crank it smokes really, really bad. When I ride it the low
end seems to be good, but when it gets about mid -throttle it bogs
down. Ihave checked the copression and it has 140 psi. I have also
removed and clean the carb. I am running a 50:1 ratio on the oil/gas
mixture. I rode it yesterday,and when I got off hte bike to check for
leaks the engine started reving up on its own. The engine went to full
throttle and ran that way until the fuel ran out of the carb.(the kill
switch is missing, i had to turn the fuel off). Anybody have any ideas
as what is going on?

[oldfart]

First thing, fix the kill switch. Next, find out why it is reving out
on its own. It could be an air leak between the carb and cylinder or
more likely, a stuck throttle slide. Welcome aboard and Merry
Christmas. OF

[Dave Garner]

Post by Nappy
Hi Guys,
I am new to this group and hope someone can help me. I bought a used
1991 Honda CR250 off of e-bay. I was under the impression that the bike
ran good, but it doesn't. I have a really hard time getting the bike to
crank. It wil only crank if I spray so carb. cleaner in the cylinder.
When it does crank it smokes really, really bad. When I ride it the low
end seems to be good, but when it gets about mid -throttle it bogs
down. Ihave checked the copression and it has 140 psi. I have also
removed and clean the carb. I am running a 50:1 ratio on the oil/gas
mixture. I rode it yesterday,and when I got off hte bike to check for
leaks the engine started reving up on its own. The engine went to full
throttle and ran that way until the fuel ran out of the carb.(the kill
switch is missing, i had to turn the fuel off). Anybody have any ideas
as what is going on?

You have a bad clutch side crank seal. All the symptoms are classic.
Hard to start, smokes bad, bogs or sputters at throttle, air leak.

You can replace it yourself but you need to get a shop manual so you
understand what you are doing.

The reason it ran at full throttle is because it is now low on
transmission oil and instead of sucking oil it is sucking air. Fix the
seal before you ride it again or the repair bill will go up dramatically.

[Wudsracer]

Post by Nappy
Hi Guys,
I am new to this group and hope someone can help me. I bought a used
1991 Honda CR250 off of e-bay. I was under the impression that the bike
ran good, but it doesn't. I have a really hard time getting the bike to
crank. It wil only crank if I spray so carb. cleaner in the cylinder.
When it does crank it smokes really, really bad. When I ride it the low
end seems to be good, but when it gets about mid -throttle it bogs
down. Ihave checked the copression and it has 140 psi. I have also
removed and clean the carb. I am running a 50:1 ratio on the oil/gas
mixture. I rode it yesterday,and when I got off hte bike to check for
leaks the engine started reving up on its own. The engine went to full
throttle and ran that way until the fuel ran out of the carb.(the kill
switch is missing, i had to turn the fuel off). Anybody have any ideas
as what is going on?

I think the compression is low and the carb jets are not as completely
clean as you might think. . If you don't know the accurate history of
the top end, you ought to do the top end to check everything out.
A set of rings is in your future. A new piston kit would be good
insurance against metal fatigue..

Kill it by putting it in gear and gently letting out on the clutch
while holding down the rear brake (or, install a kill switch).

Killing the fuel supply seriously leans the carburetion before it
dies. This is causing the revving you are describing.

Jim Cook
Smackover Racing
Gas Gas DE300
Team LAGNAF
www.smackovermotorsports.com