can't reach max rpm help!

[Dr Honda]

The thing is... down in the regulator... there is a valve. If it's not sealing (Because of corrosion) it won't do it's job. The regulator can bee disassembled, and all the internal parts can be checked.

 

[Thumper3322]

The bottom housing can be disassemble more than just taking the bellow out? It looked like one solid piece.

 

[Dr Honda]

If you look up inside... the valve has a slot. That can be unthreaded, and the internal valve will come apart. I think it's shown in the manual.

 

[Thumper3322]

Huh... The manual does show separate pieces, but not really how to take that apart.

So I guess I the best place to start is block the water and see if I get max rpm and if I do take it apart?

 

[Thumper3322]

UPDATE!!

That didn't do anything lol. Ran about 300 odd feet with it pinched and still max rpm 6450.

So... For S&G's I took off pto rave valve cover and pulled on the plastic cup (not sure what it's called) and could tell there is a problem. Pulled it out and the plastic cup threads were gone, so the valve wouldn't screw into it. They were shredded. The mag side same thing. What would cause this?

I'm guessing this would stop the valve from opening and causing it not to reach top rpm?

Replaced last year - race valve housing, new valves, new I o rings, new plastic cups. Only
thing didn't replace was the rubber bellows. Could not replacing the bellows cause this? They seemed fine with no holes.

 

[n3k0de]

I wouldnt take it apart... If its sealing leave it...

 

[Thumper3322]

Don't have to. what about above?

 

[Thumper3322]

I just read... that if rpms never get up enough to fully open the valves, the excessive heat from the exhaust will melt the bellows. I'm guessing in my case it melted the threads first as that would be the weakest part.

My only guess would be because my water regulator was leaking and not working right, it would have stopped my RPMs not getting to their max and the extra heat melted the bellows. Would that make sense?

 

[Thumper3322]

I cleaned up the rave valves and found that there are scratches/gouges on the edge sides to the just the top. What would cause this? When I had the cylinders off at the end of last year everything seemed fine.

pictures to come.

 

[Dr Honda]

Hum. That's not good.

How's the track in the cyl look? If they are gouged... then the RAVE's could be hanging up. Does the valve stem seem bent compared to the guillotine.

 

[Thumper3322]

That's what I was thinking.

From what I remember when I had them off, they looked fine. I cleaned them out and when using a rag it didn't get caught on anything. By hand they move in and out freely. Ya I wonder if they are hanging up causing extra tension on the exhaust valve and why it stripped the threading. Other than the slight scratches/gouges they are straight and fine.

Only thing I was thinking was there is a couple of rough spots in the bottom of the cylinder valve slots. Was thinking, take the head off (URG) push the piston down, and try and file away anything that might be sticking out on the wall?

What do you think?

Thanks for getting back!

 

[Dr Honda]

If you want to pop the head off... that may not be a bad idea. That way you can see if there is any piston damage too.

 

[Thumper3322]

I will check, but I don't think so. Last time I had it off everything seemed fine. No gouges etc in the cylinder and the pistons and rings looked fine.

What you think about trying to shave/file off the inside of the valve slots to make it a but smother? Any potential damage I could cause?

 

[n3k0de]

hijacking...

Ha hey I was out on the water yesterday for about 4 hours... I slowed down to a no wake zone and after I got out of it Mine would only hit 5100 - 5200 for about 30 seconds then went to about 6300 - 6400.. than topped out... I bought a temp / clock thing at walmart and had it near my engine and saw the temp go out about 10 degrees,, so i pulled over to a beach area and open the seat and my lower half of my pipe was a little over heated?? The coupling didnt melt because I caught it time.. Is this from the water regulator getting stuck???

 

[spx800]

To add to this, i think the TTO trailtech tach might be the issue. It's very sporadic in it's max rpm readings for me. Best i saw on it was 6720. Right before that it said 6000 and 6500; these were all after a wot run. It has a brand new wear ring, pump seal, 17/22 skat swirl, the raves are cleaned with new gaskets, my water regulator opens and closes smoothly by hand, compression is 150/150, new fuel lines, water seperator, fuel filters and a clean fuel selector valve. I can hear my rave valves open when i go from half throttle to full and there are no hesitations or bogging at wot. Since it's wrapped around the spark plug wire and receives a signal fromt he coil, maybe the coil is the issue, but i can't see that being true for every person using a TTO. The ski runs great from a stop to WOT, so I think I'm going to leave it; it's nice to have an hour meter at the least. The only other thingi can think of is the carbs aren't opening all the way since my finger throttle hits my odi grips. I may cut a notch out of the grip and see if that helps.

OP, did you ever get your issue resolved?

 

[Thumper3322]

To add to this, i think the TTO trailtech tach might be the issue. It's very sporadic in it's max rpm readings for me. Best i saw on it was 6720. Right before that it said 6000 and 6500; these were all after a wot run. It has a brand new wear ring, pump seal, 17/22 skat swirl, the raves are cleaned with new gaskets, my water regulator opens and closes smoothly by hand, compression is 150/150, new fuel lines, water seperator, fuel filters and a clean fuel selector valve. I can hear my rave valves open when i go from half throttle to full and there are no hesitations or bogging at wot. Since it's wrapped around the spark plug wire and receives a signal fromt he coil, maybe the coil is the issue, but i can't see that being true for every person using a TTO. The ski runs great from a stop to WOT, so I think I'm going to leave it; it's nice to have an hour meter at the least. The only other thingi can think of is the carbs aren't opening all the way since my finger throttle hits my odi grips. I may cut a notch out of the grip and see if that helps.

OP, did you ever get your issue resolved?

I was just going to update this thread thx.

If you have read all the post, I was on to the rave valves as the plastic exhaust valve threads melted. Got those back together. I took the head off to check cylinders and pistons, they look fine just like last time I took them off. The only thing I did notice, was in the slots for the valves where some grooves on the sides. So I did what I could and filed and sanded them down. Not sure if it did much.

Put everything back together and went for a ride.

Before new exhaust valve, I was running 6450ish with the TTO. First wot it hit 6480ish, and at times 6500. This wasn't making sense to me.

I then took the seat off for a wot run, tightened the tto wire around the plug wire, and as soon as I got going it hit 6720, for a few seconds or 2 before I slowed down. Turned around to shore, wot 6500ish. URG.

NOW get this... My luck with this thing... I decided to try and turn the red cap flush and go for a ride with the seat back on. Didn't start right away, tried again turned over didn't start, NOW it doesn't turn over FML!

I figure the starter is jammed (2nd time this has happen, so replaced the starter last year). A few or more hours later I got it out and unstuck and back together. Those bolts are so dumb to get to. Well same thing, still running around 6450 - maybe 6500. But I raced my brothers (97 spx hits max rpms and has always been faster than mine) and we were side by side. He use to walk right past me, so I figure all is good.

WELL screw it... had a awesome (rough water for my lake today) ride to day, with my gf riding mine, and I was on my brothers. Well after getting soaking wet and having some fun, I went for a rip on mine, and now the rpms are only reading 6200. Which doesn't make any sense, as before the rave valves were fixed and after I fixed the water regulator bellow, it was running constant 6450-6480. URG!

Yes spx800 I was thinking the same thing about the TTO, not being the most reliable way to tell I guess. I think I'm going to try and zip tie it to the plug wire in a few spots to see if that makes a difference. I will also have to try more wot against my brothers, as that seems to be the best way to gauge where it is at.

One last thing (sorry for this being so long), I notice the engine is hotter now, you wouldn't want to keep your hand on it to long. Before with the WR problem and RV problem, I could hold my hand on the engine with out even noticing it was hot, only warm. This normal?

By the way spx800 how do you 'hear' your rave valves open? Neither mine or my brothers I can hear them open.

Thanks for your input!

 

[spx800]

Well, i can't hear the valves open per say, but i'm almost positive when they do since the tone of the exhaust changes after a certain rpm. I also removed that sound reducing cone that's in the rear.

 

[Thumper3322]

Well, i can't hear the valves open per say, but i'm almost positive when they do since the tone of the exhaust changes after a certain rpm. I also removed that sound reducing cone that's in the rear.

Weird, I never really hear a sound difference, only thing I have ever noticed on mine and my brothers was the jump in rpms from 4000-5000ish. They don't like to sit anywhere in between. NOW mind you mine did the exact same thing when the valves weren't opening which is weird, and the same after.

I guess I'm going to have to pop the top cap off and see if the rave valves are still attached to the exhaust valve still. Kinda a pain. All skis should come with an accurate rpm gauge damn it!

 

[spx800]

I was reading through another thread and lou said depending on the trim setting his rpms would be different. Now, when i was out yesterday the best the tach said was 6300, but my trim was all the way up. However, the ski was screaming wide open and had lots of pull, but i didn't hold it wot very long. I wonder if doing a run with the trim in the middle would show proper rpm? I think this is getting a little ridiculous since the ski's running awesome this year and this bugs me so much.

 

[Thumper3322]

Lol.... I know your pain... Bugs the crap out of to. My ski seems fine, then before my brothers walks past me, pissed lol.

I wouldn't think it should really affect it, but possibly. But full up I would think it would run higher rpm.

I wish I tested the tto on my brothers first before I mounted it to mine with the sticky pad. Just to see.

is it zip tied down, try onthe opposite plug.

I can't test for another week booo.

I'm glad I'm not alone.

 

[spx800]

Lol.... I know your pain... Bugs the crap out of to. My ski seems fine, then before my brothers walks past me, pissed lol.

I wouldn't think it should really affect it, but possibly. But full up I would think it would run higher rpm.

I wish I tested the tto on my brothers first before I mounted it to mine with the sticky pad. Just to see.

is it zip tied down, try onthe opposite plug.

I can't test for another week booo.

I'm glad I'm not alone.

I think trim did have something to do with it, or maybe it was just a coincidence. We were racing on the bay this weekend, so my trim was at times full up and in the middle approximately (sending unit is faulty, so I have to guess), but I was hitting 6960 consistently and at one point 7200! Checked the service manual and the rev limiter is between 7150-7250, so the prop must have been out of the water at some point.

 

[Thumper3322]

Interesting... That's great. Now did you zip tie down the wire to the plug wire? Which plug did you run off of?

What were you hitting when you trimmed it all the way down?

My trim stopped working after last winter, so I'm just above mid position until I fix it I can't test it. However I can't really see it making a difference, only on speed. Hmmmm

Thanks for the feedback.

 

[spx800]

It's not zip tied, but wrapped 6 times tightly, and then tied using the remaining wire. To my rec-election it's on the PTO wire. Like i said, the trim position could have just been a coincidence, but i found it odd. I don't remember if you stated earlier, but do you have a finger throttle?

 

[Thumper3322]

Well that's good. I'm sure it was just a coincidence. But it sounds like you gut it tight and not coming loose. I will be trying that this weekend to see, with my fingers crossed I'm good.

No... I have the thumb throttle.

And shouldn't matter cause your would only have to adjust the throttle cable.

 

[spx800]

Sometimes, depending on the grips used, the finger throttle doesn't allow the carbs to open fully. It was just a thought.