Power valve again

[moped]

I have the '01 Yamaha GP800r.

I took it to the dealer to get winterized, the mechanic called and said that he "heard a noise" during the process. He then told me that this model has been known to have probelms with the power valves and that they wanted to pull the head to make sure there isn't any damage. I'm familiar with the power valve issue, planned on replacing the clips before next season.

The last ride I had of the season I did notice a loss of power.

Should I have him do the work, or is there something else that I should consider?

Thanks!

[Technical Support]

Re: Power valve again

He's absolutely right.

[moped]

Re: Power valve again

Thanks for the quick reply.

I'll have him check it out.

[moped]

Re: Power valve again

Spoke to the mechanic and asked for a ball park quote of repairs. He said anywhere from $700 to $1500, depending on damage done.

At this point, I'm going to park it for the winter without repairs, but am seriously considering a new motor if repairs prices are competative with just replacing the engine.

How easy is it for someone with limited mechanical skills to to the insall (I fix computers, a slightly different world)? I have decent mechanical aptitude, but have never attempted anything of this size.

Any suggestions?

[ISLANDRACING]

Re: Power valve again

If you can use a 10mm wrench, you can pull the pv covers ( 15 min job )and check if there is a dropped valve--- also was the compression checked on the motor?---
try the simple things first -- may avoid costly repairs.--- pull them covers and report back on what you find.

[1fastski.com]

Re: Power valve again

if all you endup needing is a topend job your looking at maybe 300 bucks in parts . you could do the work your self if you take your time and use the fourms for help .and dont mind getting dirty :-)

[moped]

Re: Power valve again

Thanks Islandracing and 1fastski.com.

I'll pull the covers first chance and report what I find. Thanks for the help!

[SP]

Re: Power valve again

In regards to prevention, waveeater clips and.....

Let the ski cool down, don't gun it on the way back to the ramp, go slow and let it cool down. Once on the ramp if you rush to put it on the trailer and then start it up and gun it to remove the water you are asking for problems, then engine is cooling and changing size at different speeds and lean siezing and powervalve dropping results.

Also start warming up slower too like 10 minutes when you take it out.....

[moped]

Re: Power valve again

OK, after a long crappy winter, we finally got to inspecting for the engine problem, and we found...

We pulled the head and the pv covers and found the infamous pin popped out on the front cylinder. Luckily it didn't fall in or allow the pv to slip into the piston. BUT, the shaft to the pv was snapped IN HALF!

Here is the new problem - now we can't get the rest of pv out. It currently has about 1/4 play moving up and down, but that's it. Isn't it supposed to easily slide out through the pv opening? My thought is that it's hanging up on some sort of "lip" and doesn't have enough room to get it passed (sorry for the laymans terms). I thougt about drilling it out, but any and all suggestions are more than welcome (even taking it to a qualified mechanic).

There appears to be no damage to the piston or cylinder.

Thanks in advance!

[ISLANDRACING]

Re: Power valve again

Moped---If there is still a piece of the shaft left you can grab it with a needle nose vice grip--- a little bit of WD-40 will help to loosten up the carbon build up ( use only a little otherwise all the sludge will go down into the cylinder )

When you do get the rest of the valve out check to see if it is worn on the piston side---If it is this means it already contacted the piston. Look into replacing both valves with R&D Billet Valves ( since you need at least 1 anyway ) or at least the updated OEM valves ( but then you will have to add in the aftermarket clips )

[moped]

Re: Power valve again

Thanks Island.

Should I remove all the carbon build up while doing the repair or just enough to get the PVs out/replaced?

Would it hurt to leave the other, undamaged PV in and just add the waveeater clip? At $120 per PV and other parts, trying to stay low on expenses. Of course, I'll spend the money rather than go through this again if I have to.

[ISLANDRACING]

Re: Power valve again

moped- if you have the powervalves with the bronze colored bushings these were the early style ( junk ) PV's and both should be replaced. if you have the later ones then you could be fine with just replacing the one and adding the clips. my guess is that you have the early one and the top broke allowing the valve to drop rather than the pin walking out-- if the pin just walked, then most likely the shaft would still be ok.
another thing --- concider yourself lucky---MOST of the time a dropped valve leads to cyl replacement. a little investment now could prevent a future failure.

[moped]

Re: Power valve again

I agree, I got real lucky on this deal (so far knock on wood). That is, provided I can get the rest of the PV out.

What PV replacement do you recommend?

[moped]

Re: Power valve again

OK, stupid question...

Do you pull the pv out through the pv cover end? I got the vise grips locked on and pulled for an hour with very little movement. Is it common/possible for there to be enough build up cooked on that it won't fit when pulling through the cover opening?

Thanks again for all your help, Island!

[ISLANDRACING]

Re: Power valve again

Yes, everything comes out through the top. Did you remove the screw that holds the PV sleeve to the cyl??? You will also have to slide the shaft out of the cylto get the PV passed it. Probably so much crud on it you didnt even see it. The screw uses a 4mm hex key to remove.
If you want give me a call and I can talk you through the job.