Motoring High RPM Engine Miss

[Dukat]

Hi

I have a 2002 Honda CBR 600 F. When I attempt to go any higher than 3k rpm in seemingly any gear, the engine begins to miss and stutter, I can't seem to get the thing to go higher than 5k rpm - to be honest I'm reluctant to try to do this too hard, incase it causes damage.

I'd assumed it was just water in the fuel, but after buying fuel additives to absorb the water and trying it, and still getting the same problem, it seems like this isn't the problem. Atleat it doesn't "feel" like it is - the problem only seems to occur at 3-5k rpm in any gear.

Does anyone(throd?) know where I should start looking for the problem?

Any help much appreciated

 

[Shagrat]

I had a similar problem with a Fiat, fine until you hit high revs then it stuttered.

That was getting through loads of water as well though.

Turned out to be a head gasket problem

 

[Dukat]

Turned out to be a head gasket problem

ah ****

Anything specific? How much of a drama to sort out?

 

[milou]

I had something similar in a newish Fiesta (in about 1485 though) and it was caused by the HT leads breaking up.

 

[Shagrat]

ah ****

Anything specific? How much of a drama to sort out?

well it had to go in to have it skimmed down. not a drama, but not cheap...

hopefully its not that in your case, could be any number of issues, turbo kicking in etc.

 

[throdgrain]

OK.

I very much doubt it's water in the fuel mate.

If you want to check your cylinder head gasket check your oil - if there is water in the oil that is a very good suggestion that the head gasket has gone. I find it unlikely on your bike though.

Give me more symptoms, when did this start? Had you done anything to the bike when this happened? Or had it been laid up for a while?

Generally with mechanical problems the place to look first is the last place you went

Actually. Get on vent

 

[Trem]

Have you checked the plugs pikey?

Are the 2002 CBR's carb or fuel injection?

Aye I'm with throd on the gasket idea, bloody unlikely on a Honda of the age yours is. Its to do with ignition/fuelling etc.

 

[throdgrain]

From what you've said on vent all it needs is a clear out. You've said it revs fine in neutral, so it's breaking down under load.

As I said , but just to reiterate, you need to ride it round the camp again, till it's reasonably warm, then see which of your exhaust downpipes is hot, and which is just warm. Be careful, this will burn your fingers if not done properly! Spit on em then just tap your finger on the pipe, if it is good and hot the heat will evaporate the spit and not your finger. The bike needs to be properly warm for this test, i.e showing a reading on the temp guage. Quite frankly you'd be better off riding it a few miles round the town. You may well find that the problem has disppeared by then anyway.

If it hasnt, check the exhaust downpipes. The ones that arent as hot are the ones causing the problem. If it's a coil problem you will know because you have two coils on a bike, and 1 provides sparks for cylinders #1 and #4, and the other does sparks for #2 and #3. So, for example, if #1 and #4 are cool, you might well look at the electrical connections to the coil for those cylinders. If however they are all cool, or #1 and #2 are cool, you can pretty much rule out a coil problem.

This isnt a big deal, if it worked when you parked it up not a lot will have gone wrong on its own. check the conections. To everything. There's not a lot more I can tell you without more info, frankly looking at the bike is easily the best way.

If this is all a bit daunting I think you might want to take it to a bike shop to have a look at. It may cost money, but it will get it fixed. The first thing you need to do though, is ride it for a bit and see if it clears out.

 

[MrHorus]

Had a similar problem with my old VFR 400.

Turned out to be the carbs fucked