I have a 93 cbr600f2, i got the bike second hand been running great but now its jerking at low rpm say under 5k..

what could be the cause of this?
i have been running 89/93 octane fuel right now it has 100octane in it kinda weird my pinging didnt go away till 100octane.

it has a yoshi slip on and soon to have a BMC filter i plan on re-jetting it(stage 1)

thanks


Mitch

 

You got clogged jets or too much carbon buildup in the intake or combustion chamber. The high octane is needed to reduce pinging because the compression has been raised so much over time because of the carbon build up. I would get the fuel system cleaned out.

 

will running the higher octane help to clean some of it out? also whats all involved in fuel system cleanin that i can do when i change the jets., sorry for the newb questions but im FI spoiled


Mitch

 

I got the same problem 1st thru 3rd gear it does it at about 4000 to 4500 rpm above or below that it doesn't do it. but ifI go to a higher gear say 5th and 6th itsmooths out, thought since I have an old chain plus when I took it off to clean oncewhen I 1st got the bike I pressed the master link a little on the tight side soits got a slight kink ( been too lazy to pull it back apart plus I don't have a chain tool [:@]) soooo when the chain travels aroundI can feel it more when the chain is a little dryand needs adjusting, so my thoughts were the chain[&:].Is it wishful thinkin, its the chainor do Ineed a carb job ?

 

i just put a 520 conversion chain/sprokets on about 600miles ago, no change in this problem but it rides smoother at high speed.. i think im gonna just rebuild the carbs when i do the re-jetting, anyone know where i can get a syncing gauge? and extra carb parts? (stuff that isnt in the re-jet kit)

as for the carbon build up in the combustion chamber/intake, what can i do about it short of rebuilding the engine?

thanks again, mitch

 

well after running the bike hard on 100octane its starting to run better and some days worse, all these problems came up after changin the oil and goin on a 250mile ride. any ideas , WTF is goin on plugs are only 1000miles old. is the 100 octane gonna hurt the engine at some point?

 

Clean your carbs. If that doesn't cure it put new plugs in.

 

What type of oil did you put in? If you used a different type/weight than the bike is used to, it could cause some problems.
As far as cleaning goes, I would use SeaFoam. Before doing the SeaFoam, I would do a compression check just because it sounds like your compression is really low.
SeaFoam can raise your compression some, and you might be able to use lower octane gas... plus your carbs will be clean. Maybe you should also put some in the crankcase, ride 100-200 miles, then change the oil and filter again.
You should also go ahead and sync your carbs.