RG150 short on power

[Sharft 6]

I recently bought an RG150 because I had already test ridden someone else's and I thought the extra power would keep me entertained for a while.

Unfortunatly though, mine is really sturggling to get to 100km/h.

Petrol
It came with very little fuel in the tank. It now has fresh (4day old) fuel.

Oil
It had an oil leek and very little oil in it when I got it. The oil leek is fixed now and the tank is full of fresh (about 3 weeks old) oil.

Battery
It came with a flat battery so I have replaced it with a brand new one.

Spark plug
I replaced the spark plug with a new one that happens to be colder. I think it prefers the old hotter one.

Power vavles
I have spent hours on the power valves because from what I've read, I thought this was by far the most likely problem.
The right power valve is somewhat 'flogged out' in the middle but I can guarantee the valves are fully actuating under the power of the pulley system. I did a test with the valves left as is vs stuck open. It accelerated a little faster when the valves are left as is. When the valves were stuck open, there was no kick of power in the high end. Instead, it ran out of puff at exactly the same way as it did before.
If I leave the bike in neutral and rev it up, I will see the pulley turning and notice the rpm increase when this happens. When it's under load, I don't think it has enough power to reach the power band. It's quite hard to see the pulley directly from the side while riding the bike, but from what I can see, the pulley doesn't move while riding.

Warming
It's quite hard to warm up but I got it to 1/8 on the temp guage for testing.

Carbretor
I opened it up to find the cleanest carbretor I've seen yet. And I've seen 3.

Cylinder
I did a dry compression test and it's blowing about 100-105psi. I have no idea what the compression should be though.
I'm about to open up the cylinder and clean off the carbon deposits.

Exhaust
I'm about to decoke the exhaust.
Either the expansion chamber is a strange shape or it has dents in strange places. Will take some pictures later and post them if necessary.

In case you're wondering why I haven't posted any RPM figures, it's because the rev counter doesn't work. I don't think I'll need it after the bike is fixed anyway.

I'd really like to have the bike ready for the trackday next weekend so if any of you have suggestions, please send them my way.

[Sharft 6]

Ok so I finished cleaning out the carb, exhaust, piston, and head then put it all back together again.

None of the above really required much cleaning so I had my doubts. (which were confirmed with no performance change later)

Then I filmed the power valve pulley while riding and noticed something that might be useful. Every time the valves open, there is a drastic power loss instead of a gain.

http://youtu.be/7mWgjDSl9U8

Any ideas what could be causing that?

[Ocean1]

I'd say it's hugely out of adjustment, but I don't know much about such things.

Good work so far, though, you'll get it in the end.

[Sharft 6]

I tested them while adjusted correctly to the marker but when I had the valve cover open, I noticed there was room to open them more. So I over adjusted them which seemed to make things slightly worse if anything.

Will try under adjusting them tomorrow and see what happens.

[Asher]

You would be best checking the adjustment by taking the chamber off and feeling the power valves by hand and using the grey wire test.
Compression sounds decent.

[Sharft 6]

by grey wire do you mean connect the yellow and white wire to the negative terminal on the battery?

Also, you say feel by hand. What should I be feeling for? The valves fully open with a tiny bit of play?

Cause I've already done that.

[iranana]

I don't know much about RGs but did you check your jetting while you had the carburettor open? Cause if it's still sputtering even with the valves open all the time, seems like it could be a carburettion issue. Someone might have messed with the jetting and muddled it up at some point... perhaps it's worth checking? Check the needle jet to make sure it's not worn and running rich too.

[Sharft 6]

I tried under adjusting the valves about 2mm but I didn't really notice much of a difference. I didn't want to adjust them any further because I'm not sure what part stops them from touching the piston.

The pilot jet is 20 and the main jet is 185. The air screw is 5/8 of a turn out.

The needle still looks symetrical so I think it's fine.

The RG150 is definatly the easiest of my bikes to start and one of them is eletric start, so that's saying something!

I think it runs ok too, until the power valves kick in.

[riffer]

Might be stupid question but you do have it all connected the right way around? As in the power valve is actually opening, and not closing? Not sure if you can do that, but with two cables connected to it, it seems a possibility.

[Sharft 6]

heh, i supose it would be a possibility with longer cables if you crossed them over. But no the vavles are definatly being pulled out when the pulley turns.

maybe I'm not using the word open and close how I should be. I mean open when the valve is being pulled out, creating more space in the exhaust.

[koba]

Make sure the battery is in good condition, you say the rev counter doesn't work - normal for a bad battery which will also stop it running well up top.

[Sharft 6]

Battery is 4 days old. It's also been charged.

[speeding_ant]

Unrelated, but quick tip for getting the RG nice and warm in our NZ climate: block off the front 1/3 of the radiator with aluminium plate or similar. They were made for Thailand climates, made a big difference for my old one a few years back. Never overheated, just got warm like it should.

Can't help with your problem though Unless of course you haven't warmed it up properly before giving it a good fang.......

[eelracing]

The pulley in your youtube vid barely looks like it is turning...maybe 1/8th max.

Are you absolutely positive they are fully opening because it doesn't look it

[oyster]

Comp tests unfortunately are all a bit subjective. I have a special screw in version for rg's and i'm normally looking for 140-150psi. I had one recently, running ok but slow. It had 100psi. On inspection major seize damage to piston rings. If your piston looks in tidy order, ie not seize marks etc, it should go ok. A worn out one will be down a few hp, that means 150km'hr, rather than 160. A low comp one also usually revs out ok, but really misses out on the "roll on" drive from 9000 to 1100rpm.
Re power valves, to isolate your problem. Disconnect at the pulley and turn them wide open, wire in this position. Then start and run OK like this, but run pretty flat and rough from bout 3000 to 8000rpm. From 8000 up to red line they go like a bullet, as per normal one. If you do this and can't get it to go at the "top end", you have another problem. Very rare to have an RG with good comp, valves wide open and not go well at the top end.

Never heard of it, except on a KR150, but check free flow of chamber. The baffling/silencing inside may have come loose and run to the back, blocking things. Take off and shake it to test. Loose bits, big prob! Final place to look is crook carb/airbox. Swap out with one that works to trial. If you are in chch i can look at the bike, should get to prob ok if that helps