Need help. BOG!

[Logan #34's Dad]

Okay fella's, i've been at this game a long time and I cant figure this one out.
My 90 runs very strong. But if i stab the gas it bogs to the point that if I kept the throttle pushed in it would stall and die. This seems to happen when i come off the throttle then stab it. Not good for motocross! It also seems to get worse as the engine gets warmer.
We just replaced the complete ignition - not it.
adjusted the float - not it.
changed jetting up and down - not it. (i believe)
Definately not clutching cause it does it w the wheels off the ground.
This is a new deal with this engine - and I've changed nothing.
Any educated guesses would be great!
2fast, Haggerty, 30mm carb.

[Ryko racing]

ck the vent for the gas tank.

if thats not it ck all of your overflow tubes on the carb ( or remove them one at a time)

lastly if you run a oko carb it may be time to replace it.

good luck

[Logan #34's Dad]

Thanks for the input. The vent tube is not it either. The carb itself maybe the issue. I believe it has to be a carb area issue but I can't figure it out. I'm hoping someone else may have had this issue and it turned out to be something different.
Driving me crazy and killed us at Loretta's! Did not even make a lap in one class but made the whole earlier moto BUT was bogging.

[Ryko racing]

airleak?

Do these have reeds ?

did u ck compression?

just brainstorming.

CK flywheel it may be rusty and grounding.

[riding4fun]

Rocky, When I cleaned my carb out one time I forgot to put back the little brass piece that the needle goes into. It would idle but as soon as I mashed the gas it would die.

Another thing did you take the air screw out and clean it.

[Logan #34's Dad]

Vent tube is good.
Airleak is a possibility.
what if there was a lil water seeping in the cylinder would this cause this? I don't wanna really tear the engine apart unless.....
The flywheel thing I will check.
It does have reeds.

[hwf-racing]

We just had an issue with our reed valve and it had the bog and ran like a turd. R&R petals good to go!!!!! Hope it helps! Good luck, Derek

[Logan #34's Dad]

Okay, I'll check the reeds. Thanks
Keep the input coming.

[Ryko racing]

be careful with the water issue, on cobras even a small drop in engine usually blows the lower rod bearing.

i bet the reeds are bad...

[Logan #34's Dad]

I SO hope it is just the reeds!

[travis rimmer]

we had a oko 28 carb and our quad would do what your saying not all the time but at the times it matters most like on race day it would drive me crazy i kept trying to figure it out with no luck just went ahead and bought a new carb no problems since dont know if this relates to your problem but i hope it helps

[zach R 7x]

Hey Rocky, We are running the same set up and ran into the same problem! Mine is not quite as bad as yours.

I believe it is the carb.

Now I got carb and slipper sprocket problems!!!

[Logan #34's Dad]

Yeah Tim, I'm gonna pull off the carb and go through it and hope for the best.
As far as the slipper sprockets....... they have cost Logan multiple moto/overall wins this season. I believe these motors are just making too much power for the equipment to handle. One thing I have learned - the replacement pads are not as good as the original ones that come on the new sprockets.
If someone comes up with a transmission that would not break they would get rich!
How about a single steel bar running from the clutch to the sprocket? Obviously the sprockets would be the issue as far as the right sizes but ......... 1:1 ratio tranny would require some wacky sprocket sizes.

[fish-d-fish]

Hey Rocky, We put a new carb on ours when we had the same problem. I also fixed the one we were having trouble with. Pull the choke lever assembly out and check to see if the rubber stop on the choke has rings worn into it. It will allow fuel to slip by it when its turned off under a load. This can happen from wear or from carb cleaner getting on that softer rubber. As for the tranny and such, message fullthrottle00 and chat with him about what they do to make bullet proof trannys. They are west coast riders and have it figured out pretty well from what he says in his opinion. I also have some questions for you on clutching and the Malossi Big bore porting. We work very closely with Rich and Michelle and race TT..my number is 724-612-3831. Hope you get the bog figured out!