2 stroker carby issues...

[Fireproof]

Not sure if this is the right area for this question but anyway...,
I am having trouble with my rgv150 which i think is a carb issue. It seems to get to certain revs, ie between 5500-8000 and the engine will start to stutter and 'bog down' for a few seconds before picking up again and continuing on to redline. It is less noticeable if you accelerate slowly through the rev range, but get to say 6g and then give it a bit of gas and it will happen. It seems like the engine is 'leaning out' at this point or something similar.
I am coming to think it may be happening at a consistent point in the rotation of the throttle rather than set revs. I have asked for help to no avail so far.
I have taken the carb (mikuni vm26ss) off and cleaned it out with no change, the bike has only done 2500km, 1000 of which i have done in the last 3 weeks of owning it. And no it doesn't have powervalves(!) Anyone got any clues??

[k14]

A spluttering like you tend to indicate normally means it is running rich. Has someone else altered the needle settings? Do those rgv's use reed valve's? If so there could be a chipped reed. If not then I'd say the needle is running lean.

That is if infact it is a carb problem. Could be something else, maybe electrical? Have you changed the spark plug to see if that makes a diference?

[Fireproof]

Yes i replaced spark plug. The old one seemed in relatively good condition, so i had assumed it wasn't running rich but i guess it had only done 1500km. I have not played with the carb internals. On the specs sheet it says...
'Intake system : Piston and reed valve SSS, SIPC'

[curious george]

Actually at that rev range, I would suspect something with the powervalves.
That is assuming nothing has been changed with the carbs, nothing blocking them, clean filters etc....
Check your cables operate freely, adjusted correctly, check static opening on startup.
Maybe just clean them out.

[F5 Dave]

Just to clarify an RG150 is the watercooled Powervalve equiped bike

the RGV150 (oddly a single) is the aircooled non Powervalve equiped bike.

As an aside these seem to like to kill thier oil pumps. I would seriously keep an eye on the oil level to ensure it keeps going down. Most oil pumps are totally reliable. These seem to have issues. Sadly a conversion to premix is a little difficult as the pump feeds the RHS bearing, which is an odd setup. Some oil in the petrol wouldn't hurt though.

I assumed when you cleaned the carb you blew through the small pilot jet & changed the sparkplug(said you did)/cleaned the airfilter?

[Fireproof]

I assumed when you cleaned the carb you blew through the small pilot jet & changed the sparkplug(said you did)/cleaned the airfilter?

Yea, did the basics when I first got the bike. I have also been keeping an eye on the oil level and seems to be ticking through ok but am not sure of the exact ratio it feeds in. When is the pilot jet coming into play? Is this around half to 3/4 open throttle or is it in use throughout the range?

[F5 Dave]

Pilot jets works throughout the range but really only has much affect in small throttle openings. With slide carbs yes it is best to think of them being throttle position rather than rev related. If you do block one or another jet this is the type of symptom you get (often along with dicky starting).

Would be good idea to check sparkplug cap.