can't reach max rpm help!

[Thumper3322]

I've done so much to this thing and still won't hit near 7000 rpm. The max I can get to is 6360.

Just fixed the water regulator bellow, no more leak. But didn't really change my max rpm. Low end to high end seems better.

I'm at a loss, please help.

 

[Dr Honda]

Are the RAVE's opening?

What's the compression?

Have you verified that the carbs are opening all the way? With some aftermarket grips, they don't.

 

[Bills86e]

If you ever had any water in engine, that may have worn the RV clearance, and the manifold pressure excapes into the opposite lower case. Your shop manual has the proceedure to check its tolerance specification. If you previously had the RV plate off, it may have gotten
re-installed backwards, and that could make timing a 1/2 tooth off.

 

[Thumper3322]

Are the RAVE's opening?

What's the compression?

Have you verified that the carbs are opening all the way? With some aftermarket grips, they don't.

I have new raves, housing, gaskets, o-ring etc. They seem to be as around 4000 mark you can really feel a difference in pick up and rpm change. Any other way to check?

MAG is 151, PTO is 143 so ok

Don't have aftermarket grips... I adjusted them so they stop just before the stopper and look to be set perfect. Did the exact same thing on my brothers for set up and he is running 7000 no problems.

Anything else I can check?

Thx!

 

[Thumper3322]

If you ever had any water in engine, that may have worn the RV clearance, and the manifold pressure excapes into the opposite lower case. Your shop manual has the proceedure to check its tolerance specification. If you previously had the RV plate off, it may have gotten
re-installed backwards, and that could make timing a 1/2 tooth off.

Not me personally, but used so I don't know. I have never taken it out, nor do I know how to. Is it a big job, I'm getting SO tired of this. I have spent more time than anyone should have to on this stuff.

 

[Dr Honda]

I adjusted them so they stop just before the stopper and look to be set perfect.


Anything else I can check?

Thx!

That's right... we just talked about the carbs a week or so ago.



UMMMMMMMMMMMMMM...................


Just for giggles... try turning the RAVE adjusters all the way in... and go for a ride... and then try them flush with the housing.

 

[Thumper3322]

That's right... we just talked about the carbs a week or so ago.



UMMMMMMMMMMMMMM...................


Just for giggles... try turning the RAVE adjusters all the way in... and go for a ride... and then try them flush with the housing.

If you remember, they seemed to be in a little which I fixed. URG!

Ok... thanks I will do that tomorrow. They should come out at a higher RPM correct? My water regulator valve is set flush with the housing fyi. I never adjusted this, just replaced the bellow. Was SO hoping that was the issue.

Using the TTO for RPM reading as well btw.

 

[Thumper3322]

So did that doc, running 6450 at the most. So a little more now. Screwed in or out same rpm.

when hitting a wave
it will rev up to 6900, as when I shut off it gives me max rpm.

Anything else I can check?

New plugs as well in it and the solas xo impeller.

 

[Thumper3322]

What if I took my old rave valves and cut them off so the exhaust port is completely open and see if it will reach max rpm?

I know my low end will be gone, but just a test to make sure they are opening.

It feels like they are cause at around 4000 on the throttle a little more throttle makes a big difference.

Thought?

thx!

 

[n3k0de]

Do you know if your water regulator Bellow is Stuck? or Moving? If it is stuck it could be flowing water non stop and not letting the pipe Dry out and you will not get full RPM's @ WOT..

 

[Thumper3322]

I just replaced the bellow, and no water is leaking out of it. How else can I check it?

 

[Thumper3322]

The water regulator housing you screw all the way down on the exhaust right?

 

[Dr Honda]

I almost hate to say to try it... but lets dry out the pipe for a short run. Clamp the hose between the regulator, and the head pipe. DO NOT run that way longer than just a test. You will burn out the couplers.

No... don't take the RAVES out totally. You could make a bog, big enough to never get past 4500~5000.

 

[Thumper3322]

Ok... For the safest way, I would assume warm it up first etc, then dock it, pinch the hose, start and wot and see what it reads? If it is going to work would I see it spike to full right away, or would it take like a minute to dry out?

I attached a pic, is this the hose I'm suppose to clamp?

Thanks doc!

 

[Dr Honda]

Yes... get it warm first.

Pinch the other hose, going to the pipe. We still want the water in the water box.


One other thing... have you pulled the big rubber hose off, and check to see if it's deliminating? It can happen, and block the exhaust.

 

[Thumper3322]

Ah ok the other small one. I will have to wait till next weekend to test it.

The hose from the head to the exhaust? #2 in the pic? I have pulled most hoses including that one and they look ok.

 

[n3k0de]

I did this... You can run it for about 300 feet than it gets super hot.. I ran Mine with the seat off just for a little air cool... anything helps.. check back with progress!!

 

[Thumper3322]

300 feet isn't very far.

What doesn't make sense to me is the water regulator shuts off the water to the exhaust at high rpm, so why pinching that hose and running at wot would cause problems?

 

[Thumper3322]

Did it work for you n3k?

 

[Dr Honda]

300 feet isn't very far.

What doesn't make sense to me is the water regulator shuts off the water to the exhaust at high rpm, so why pinching that hose and running at wot would cause problems?

It doesn't close it off totally. But... if the water Regulator isn't working... you will have a full load of water, and it will hurt the top RPM's. Without any water... the pipe will overheat.


The hose I'm talking about, is the exhaust hose. The big, 3" hose that goes from the waterbox... up and over the driveshaft... and out the hull on the starboard side.

 

[Thumper3322]

I will test it this weekend. thanks.

Lol... Nope I haven't taken that one apart, probably the only one left that hasn't been.

 

[n3k0de]

Well mine was stuck open always flowing water, I to had a leak and put a new bellow in it also I put a clear hose on mine for testing and yes it always flowed. I purchased a used WPR on ebay and put the new bellow in it and i hit 6930 - 7k on WOT... I did the same thing replacing the RAVE but they were so perfect i Ruled them out.

 

[Thumper3322]

Weird why the housing would cause the problem. I used a zip tie to hold the bottom of the bellow down. It seems to move freely.

Good idea on the clear line to check. What size is it and how long did you buy?

 

[n3k0de]

Not sure I cut it off a hose pump i had lien around and used a hose clamp and screwed it tight.. I took a black magic marker and made little lines like this | | | | | | | so I could look down and see water flow... other wise you are going to fast and you dont need to focus as hard to tell... its a simple look and done... water is clear .....

If you take apart the Water Regulator.. Does the fitting just pop out ? Or is it in there like it is almost snug or just fits?? Than Did you screw the screw all the way tight? Test the Bellow if there is movement? by Blowing and sucking why holding your fingers over the holes... I had the zip tie as well the one off ebay had the OEM clip in there with a little rust so I wire brushed it and greased it up..

 

[Thumper3322]

Thanks good ideas. I don't have any clear lines on me, why I was asking earlier in the week. If the rain stops sometime this weekend I will give it a go cutting off the water supply.

does the fitting pop off? When I take the top clip off the spring pushes up hard. With that off the bellow seems to expand up to just past flush with the housing. If that makes sense. Yes I screwed it in tight. The bellow seemed to move up and down with out problems. I have not tried blowing into it.

I will try running with it clapped and see. If it does make a difference then I guess I will have to take it apart and see what's up.

one thing tho... The top cap, when I put the clip on to hold it down it doesn't sit tight flush against the bottom housing. I can kinda rock it from one side or the other because it isn't right tight. Should it be? Would this matter?

Thx!