RG150 gooey powervalve and random broken spring [Archive]

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beanz

28th March 2004, 21:43

Hi, took the exhaust valve (power valve) cover off, and found my poor power valves covered in thick gooey black stuff, with 2 bits of broken spring sticking out.

I'm guessing the spring bits (which look like they were once one spring) are not meant to be floating around aimlessly in there, so does anyone know where they're (its) meant to live?

Also, where has all this black crud come from? Anything to do with my dead spring? The stuff looks like its a chunky mixture of carbon and oil.

Cheers!

Two Smoker

28th March 2004, 21:50

Common fault with the RG150's. DOnt worry about the carbon and shit because it does get exhaust gasses etc in there... just clean it out,

If you undo the top centre screw, this releases a small piece of bent metal which holds the 2 springs down (on either side of the screw), take this out and check if the other one is there, if not, well then you powervalves cant be working too well as the springs help push the powervalves out....

Mine is currently running off 1 spring as a temporary fix until i buy i new set....

DEATH_INC.

29th March 2004, 21:07

Also, where has all this black crud come from? Anything to do with my dead spring? The stuff looks like its a chunky mixture of carbon and oil.

Cheers!
That's what it'll be orright,a mix of carbon and oil.Run decent oil and get the premix setting checked,you could have too much oil getting in there....

F5 Dave

30th March 2004, 13:12

Guys be careful.
The powervalve assembly should be stripped & cleaned every so often or it will crud up, but worse if the sliding bit holding it all together chatters away the valve will fall into meet the piston & it will get real unpretty quick.

This is not an unheard of problem on the 250s (like not if – when) I believe the 150s are similarly affected.

beanz

30th March 2004, 17:22

Pulled it all apart today, and yep, the middle bit of one PV is pretty shagged. The nut and bolt had come loose, and the middle bit was floating around munting itself. I've heard they're $300 EACH for new PV's so I'm not about to get new ones. Will prob fill it with weld metal, then machine it up.

And both the springs had broken off too. Man, it was like a used grenade in there.

Anybody with a pair of PV's for me? :whistle:

Two Smoker

30th March 2004, 17:54

Yea a couple for me too :msn-wink: although im hoping the nicks in mine can be polished out..... $300 sounds good, COlemans quoted me $400 each there :wacko:

beanz

31st March 2004, 10:56

Sounds like a really common problem on RG's. I'm sure gonna check mine every 6 months from now on. Just need to pull them out, check the springs are still springy, and the bolt is still tight, and clean out the carbon from everywhere.

It seems like a 2-fold design flaw. 1st, the little nut and bolt which forms the sliding stopper for the middle blade can work itself loose, wearing a decent hole in the middle blade, and allowing it to protrude too far into the cylinder and hit the piston. 2nd, the spring can goo up with hard carbon, turning it into a rod rather than a spring, which breaks the spring retainer plate when the valves try to open.

Instead of welding it, I'm going to either get a new middle blade, or if thats too expensive, just fix (countersunk bolts, or pins) the middle blade to the fixed blade, as it doesn't seem to serve much purpose anyway. The big blade does all of the "valving" anyway. I think the middle blade just helps the piston rings stay in the right place as the piston passes the exhaust port.

Hope this helps any other RG owners out there, as if left unfixed, this problem could hand grenade your whole engine.

F5 Dave

31st March 2004, 17:24

Yeah I had a friend making valves but it became uneconomic. Regular cleaning will stave off the problem & a decent machinist my be able to recon them by sleeving them perhaps. Oven cleaner should help clean them but don’t leave it on for too long & clean off after.

jimdaworm

29th June 2005, 08:15

Does anyone have a photo diagram/how to for pulling out and cleaning the power valves?? :yes:

beanz

29th June 2005, 09:31

Yeh, I've got the service manual in pdf, but its like 100Mb or something. Its divided into a separate pdf per section, so I'll dig out the right one and stick it up on my website. You'll have to give me about a week tho, cos I'm living in london and in the process of getting a fast internet connection set up. My email is keeweechris@hotmail.com. Email me in a few days to see where I'm at.

Cheers
Chris

jimdaworm

29th June 2005, 17:59

That would be wicked, then I can print it out at work :devil2:

Aiolos

29th June 2005, 18:29

Oooh, could you also put up the bit about adjusting the oil thingo?

FROSTY

29th June 2005, 18:33

I know its a different power valve setup but I used to pull the power valves out of my TZR after every second meeting. That goop will make a fair difference to the bikes performance.
I used to use oven cleaner then a buff then autosol to get a mirror finish on the valves

ZorsT

29th June 2005, 21:05

Squiggles

1st July 2005, 18:36

jimdaworm

2nd July 2005, 09:12

Thanks a lot beanz. :)

F5 Dave

5th July 2005, 09:19

anyone know if the 1989 rgv250's are affected by the powervalve problem that the older ones seem to have had...i think it was the 91 and 92 models in which they placed the not so good pins...but im not sure...

They all have issues if not pulled out, inspected & cleaned every so often. Do it now, check that rivety thingy & clean.

jimdaworm

6th July 2005, 08:16

Hey F5 Dave, I might have to get you around here next time I have it appart sounds like you know what your talking about :devil2: I was just worried about mucking stuff up especially after someone else said if you don´t put them all back right they can go into the piston, making the bike VERY slow :oi-grr: