sferrero

Member
Sep 25, 2012
11
0
my 1997 cr80r will bog from about a quarter throttle to WOT and by bog i mean to the point of stalling. if I ride the clutch I can get it to ride but i have to clear out the carb like it is loading up..I cleaned the carb and also have tried every jet combo and needle combo i can think of, I even swapped my r&d exhaust for one stock one I had lying around. still nothing, i've checked the packing in the silencer, changed the cdi box, the coil pack, and even changed my jets to stock and everything in between. im to the point of just giving up.
 

_JOE_

~SPONSOR~
May 10, 2007
4,697
3
Top end time? Leaking crank seal? Sounds like you need to run a compression and leak down test.....
 

sferrero

Member
Sep 25, 2012
11
0
well, i had just recently put a top end in the bike about a month or two ago, and the guy i traded bikes with says he did a bottom end rebuild. is there a way to if it is the crank seal leaking??? also it did not do it as much on my old top end, i am a bigger guy riding a small bike and i know its going to bog but not like this..
 

_JOE_

~SPONSOR~
May 10, 2007
4,697
3
A leak down test will tell if a crank seal is leaking.

My buddy has a 98 and if you go easy on it for a while it loads up. Once you let it rev for a second it rips though. It never wants to stall, just gets a bit blubbery and lethargic. If yours is almost stalling there's an issue somewhere. How are the reed petals? Is it easy to start?
 

sferrero

Member
Sep 25, 2012
11
0
it starts on 1st or 2nd kick, and the reeds are brand new fmf. it doesn't stall so to say but if i'm in the low rpm of any gear and I dump the throttle to wide open it bogs down and kills the bike. now if I rev it up and get it in the higher rpm I can hold open the throttle to wide open and it revs up instead of bogging. also when I rode it I would have to take off and ride the clutch revving it up (almost like it was getting too much fuel.) and keep feathering the clutch all the way to the power ban. once in the power ban it rides fine.
 

High Lord Gomer

Poked with Sticks
Sep 26, 1999
11,790
34
If it is a true bog, that is a lean condition. If it stumbles, stutters, or loads up, that is most likely a rich condition.

I would suggest moving the clip on the needle to a lower position. This will raise the needle in the main jet, allowing more fuel. If it gets better, you have a lean condition. If it gets worse, you have a rich condition.

If the right side crank seal is leaking, you will be blowing a fair bit of blue smoke. If the left side seal is leaking, it will be sucking air in to make it leaner. To test that, you can take off the left side cover and spray WD40 behind the flywheel while it is running to see if changes. If it changes, you have a left side leak. You can also spray WD40 around the reed housing and front side of the carb to make sure there are no leaks there.
 

sferrero

Member
Sep 25, 2012
11
0
I have already moved the needle in every clip setting (3rd/middle is stock) I've also tried every jet I have for this bike (main 120,125 <stock.. and pilot 48,50,55<stock... the I will try spraying some carb cleaner in the left side crank seal to see if it revs up. And also around the boot around the reeds. it dose not smoke much when warmed up. I cleaned the carb hoping it was just gunked up. my buddy has a cr exactly like mine but small wheel and he just got a carb rebuild kit for his and we slapped it on and it did the same, so i think I've pretty much eliminated the carb.
 

sferrero

Member
Sep 25, 2012
11
0
It dose not smoke much when warmed up. I cleaned the carb hoping it was just gunked up. my buddy has a cr exactly like mine but small wheel and he just got a carb rebuild kit for his and we slapped it on and it did the same, so i think I've pretty much eliminated the carb.
 

sferrero

Member
Sep 25, 2012
11
0
I did what High Lord Gomer said to do...and for some weird reason it seemed to clear it up. I sprayed around the magneto with carb cleaner and around the reed boot and it now will rev from a dead idle to max rpm. but what I noticed is around half throttle when riding it wants to sputter very little bit. I think it might be a main jet. but 125 main and a 55 pilot which i have in it is stock for my elevation (FL) any ideas???

*and thank you Gomer!! for your advice
 

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