i have a 97 formula 500 that has a bad off idle bog, it bogs up until about 3000 rpm but then runs fine once your moving at above 4000 rpm, any ideas on where to start??

"it bogs to 3000 rpm" ? what is it supposed to engage at? i would venture to guess around 4000. unless i misunderstand you post i would look at the primary clutch.

If its at idle and you try and give it gas it just bogs, once u get it revved up past 3000 the bog is gone, yes the clutch engages at 4000.




"it bogs to 3000 rpm" ? what is it supposed to engage at? i would venture to guess around 4000. unless i misunderstand you post i would look at the primary clutch.[/b]

i think i understand, your saying its bogging before the clutch engages. so...i would check for a lean condition in the idle curciuts of the carbs, loose carb boots, maybe a bit of sludge growin inside the carbs. the pilot screws and or the carb needles may not be set right. carb sync, (both slides opening at the same time) did this start after it sat for a long time or did ya buy it like that? was the air box modded? i just touched on the most common reason for "the bog" , start there.

I think this "bog" condition happens to atleast every sled one point in it's life.

Last year, my dads sled was bogging the first time we started it. I installed new plugs and took it for a couple of WOT runs in the field. Problem solved.

While the above post may be reasons to cause a bog, I think you should eliminate the obvious. Do a couple of WOT runs and see if it improves. If not, then pull out the carbs and give them a good cleaning. If it STILL doesn't run well, check all the fuel filters, carb boots (do the whole run-around).

Does it run any better (not bog) with the choke on (1/2, full)?

i bought it a couple of years ago and it did it then, i took it to a guy last year and he claimed he cleaned out the carbs but it still did it, its all stock, maybe ill take the carbs off and clean them myself. It doesnt have a choke it has a primer.



I think this "bog" condition happens to atleast every sled one point in it's life.

Last year, my dads sled was bogging the first time we started it. I installed new plugs and took it for a couple of WOT runs in the field. Problem solved.

While the above post may be reasons to cause a bog, I think you should eliminate the obvious. Do a couple of WOT runs and see if it improves. If not, then pull out the carbs and give them a good cleaning. If it STILL doesn't run well, check all the fuel filters, carb boots (do the whole run-around).

Does it run any better (not bog) with the choke on (1/2, full)?[/b]

I took the carbs off today and cleaned them out real good, problem solved. The only thing i really saw in there was some gelatin like stuff in the bottoms of the bowls!?!? thanks for the help guys.

Great to hear, make sure you add fuel stabilizer to the tank during your last run of the season to help eliminate the 'gelatin' problem.