Jog bogs past 1/2 throttle?????

[CuRbO]

after a really hard ride my bike started to bog past 1/2 throttle. it bogs hard and dies. its weird cuz it runs normal up until the 1/2 throttle mark. i've gone through the carb twice, it seems really clean. i replaced the spark plug, no use....

can anyone help? thx.

[xraydino]

Clean your airfilter to. What did the plug look like and have you done any aftermarket mods?

[str8dum]

sounds likes its over heating and seizing.

[CuRbO]

No mods other than some holes in the exhaust to let it breath. The plug looked a little on the lean side.

I dont think its the air filter. I cleaned it not too long ago and when ive test ridden it after cleaning the carb, i leave the air box off, and it bogs down past 1/2 throttle just like when the air box is on.

What do u mean it sounds like its overheating and seizing? It boggs even when the engine is cold.

[xraydino]

The holes are your problem, JB weld them closed. Two stroke exhausts work on back pressure, holes will not give you any gain.

[CuRbO]

But it ran great with the holes for some 400 miles until recently. And i dont think that explains why it runs perfect up until 1/2 throttle and then cuts out past the 1/2 mark.......

[Zuma-Zuma]

Did your variator come apart? OR...since the pipe holes will cause a loss in performance, and a lean condition, so will removing the airbox cause it too lean out even more. Plug all the holes, run the stock box, and try it. If it runs the same, see if your variator has something crooked in it.

[StepVino]

But it ran great with the holes for some 400 miles until recently. And i dont think that explains why it runs perfect up until 1/2 throttle and then cuts out past the 1/2 mark.......

Hi curb, I don't have any input over the advice that has already
been given. However, I am curious about your exhaust holes.
Can you give any more specific info on that? Did you actually notice
an improvement that you can be fairly sure was due to the holes?
In what part of the exhaust did you make them? How much louder
is it?

thx

[CuRbO]

StepVino,

I bought the scooter about 6 months ago and it already had the holes drilled into the exhaust, so i can't compare it. I do know that a lot of people seem to be trying to get their 50cc's to do 40-45mph, which mine does without any modifications (other than the exhaust holes). It probably is a little louder. I was surprised that someone said the holes would slow you down- i read somewhere that those holes will help you go faster. Oh, and the holes are on the side of the exhaust, behind the exhaust protector plate. I think there are about 4.

[StepVino]

Thanks for the info, will try Googling for more and see what comes up,
if anything.

All I know is that it's definitely slower with the stock pipe loose on the
cylinder head. Not fully sold on the back pressure business, except for
the above. Last year I hooked a vacuum cleaner to the exhaust, at idle,
and it revved up... At this point I'm not sure how these facts fit together.

As far as you're bogging down, it definetely sounds like lean symptoms.
However, why would it take 400 miles to show up? Could it be the symptoms
of a blown engine? Never had one, so don't know. I would immagine that
if the compression were low, it would run better at higher rpm. That's
my experience with 4 strokes, but so far everything seems to work the
opposite on 2 strokes.

You could try riding with a timing light, and make sure your ignition isn't
cutting out. Another thing you could try is bypassing the fuel pump,
maybe it's not working properly. I have a bad feeling though that it's
something more serious.

[graham2]

Sounds like your main jet may have clogged with something (eg. +half throttle). Open the bottom bowl of the carb (only), discard the gas, and unscrew the center gold thing. Make sure the center hole in it is clear of obstructions by blowing through it. You can get at it by removing the airbox and the bucket-front and side panel, just pop loose the air intake clamp and pull the airbox out of the way. (Replace it with a Tekei #71 main jet while your in there if you are lean.) -G

[graham2]

Last year I hooked a vacuum cleaner to the exhaust, at idle, and it revved up... At this point I'm not sure how these facts fit together. Dude, you are too much. :smokin:
Keep us posted, -G

[CuRbO]

GUYS! Great news, i got my Yellow Jog back to perfect! You're gonna laugh, but i think most of it had to do with my airbox being off during the test rides. I'm almost positive it was on correctly when it had problems, so maybe it was something in the carb and then after i cleaned the carb and test rode it without the airbox, it needed the airbox to run correctly....i dont know. Another thing, the tube that runs from the engine to the carb (i think it might carry the 2 stroke oil) might have been a little loose after i took the carb off initially.

So basically, with a good carb clean, the air box on tight, and the oil tube reaching the carb, my Jog is back to pimp riding and wheeling. MAkes sense, right?