Power Flatspot

[jimdaworm]

Anyone know what might be causing a flat spot in my power at exactly 8000rpm and it doesnt go away until 8500rpm.

After 8500 it pulls fine and the power valves seem to kick in nicely around 9-10.

Its just really annoying as its just around the speed I normaly travel that I hit 8 in top gear and I can feel it surge and then stop pulling and then surge again.

[Racey Rider]

Surging means it's running lean doesn't it?

I'ld be asking at a bike shop.

a small 500rpm dull spot is not a big deal on a two/ , if it dies at those rev,s I'ld be trying to sort it out. But definatly surging is not good. Can lead to sezier.
See what others think.
Racey.

[vifferman]

Surging means it's running lean doesn't it?.

Yup, it does.
EDIT:
Oh. It's a two-smoker.
All bets are off then; conventional logic doesn't apply here - it's all black voodoo magic, evil mojo, and various sorts of witchery.
Time to find a tame witchdoctor or exorcist.

[Motu]

Sounds like a broken powerband to me,not so common these days as modern bikes don't use the old fashioned powerband.I have some here,but they are old and have lost their snap,but I don't mind as it suits my riding style.Try Mitre 10,they used to have an assortment.

[Ixion]

Oath. Its a two smoker. So whaddya doing trying to run at under 8000 rpm anyway. Keep it at 10000+ where two smokers are supposed to be , and you'll never notice. Seriously. Almost.

[Aiolos]

Its your powervalves trying to decide between the closed and half open positions, and failing.
Its a real pain in the ass.

[jimdaworm]

Do you have that too Aiolos? Anything I can do about it? It didnt used to do it... or maby I didnt notice it sooo much. Its just really annoying as its just aroudn the speed I like to travel at.

Motu please explain I dunno if your joking or not!

I wondered about the adjustment that I remember seeing for the power valve actuator/servo....

Ixion if I were to travel at those rpm I would be severly braking the speed limit in top gear

[SlowHand]

Is that lurching and other stupid annoying crap? I get that every now and then - thought it was just a 2 smoker thing? - cant decide whether to go balls to the wall or not?

[avgas]

Small mission to get those power valves working properly.
a) Run an iriduim plug
b) Take the bike to a race person, and get them to tune the valves for ya (in your case, ask for a linear power setup.
c) Run nice oil.
thats about all i remember from my ol' RG...for now anyhow

[Ixion]

..
Motu please explain I dunno if your joking or not!


Ixion if I were to travel at those rpm I would be severly braking the speed limit in top gear

And? It's a two smoker. Doesn't understand these "ringa dinga waddya callem ding ringa speed limit dinga dinga" things.

Oh, and Mr Motu NEVER jokes. Believe him, after all, he's a professional

[jimdaworm]

Thanks for all your info! I cant find any information on these power bands moto is talking about so I wouldnt even know what to ask for


I run it on Shell Advance VX2 ... not the flashest oil but fully synthetic. I might try changing the plug before I try other things as it will be an easy fix if it works!

[Racey Rider]

Motu is pulling your leg about the powerband.

Yes the RG150 has a powerband, but that is a 'way the motor works' not a specific 'item in the motor'. The powerband can be 'ajusted' by changing items on the bike, (ie. exhaust, or carb size), but that is only for experts to play with and totally unnessary for you..

>Its your powervalves trying to decide between the closed and half open positions, and failing.
Quite possably just this. Is the bike getting up in the km? (20 000+ for these)
Things could be starting to wear, causing a bit of slop in this area.

The type of fuel you use can exaguate (sp) issues like yours. Are you running it on 91?
91 would be the norm for a Rg150.


If you find it doesn't run at it's best at that speed in top gear,,, don't use top gear! Cruise around in 5th if you have to to keep the rev's higher.

[Motu]

Spoil sport...

[Str8 Jacket]

The type of fuel you use can exaguate (sp) issues like yours. Are you running it on 91?
91 would be the norm for a Rg150.


If you find it doesn't run at it's best at that speed in top gear,,, don't use top gear! Cruise around in 5th if you have to to keep the rev's higher.

Sorry to jump in here Jim, but RR do you think that my KR would run better on 91 then say 96 or 98? . . . Or no different?

On a side note I have found it quite hard getting used to keeping the revs up too. The KR is sure different to the mighty GN, im usually sitting around 7-8000 revs around town, should I be keeping them higher? . . . .

[Ixion]

Sorry to jump in here Jim, but RR do you think that my KR would run better on 91 then say 96 or 98? . . . Or no different?

On a side note I have found it quite hard getting used to keeping the revs up too. The KR is sure different to the mighty GN, im usually sitting around 7-8000 revs around town, should I be keeping them higher? . . . .

Probably no difference running a ringa-a-ding-ding on 91, but if it did anything it would be an improvement. No point in high octane on a two smoker. Keep the revs as high as they'll go. You gotta wring the neck off a two stroke. And being a two stroke, the revs won't do any harm (they will wear out quick of course, but that's cheap to fix)