SXR won't rev out...

[Watty]

Hi guys,

I thought I would run this by you SXR guys in case you've seen the problem before...

Setup is a stock SXR engine with wet pipe, Jetinetics flywheel, VF2 reeds and Hooker 11/17 prop...Have dual cooling from the pump with one circuit running to the head pipe and dumping overboard, and the other running into the manifold and out the head dumping overboard.

The problem we are having is that the engine will only rev to 6050 rpm, and nothing more. It revs straight to 6050 against the dock and doesn't move from there.

Jetting is per fpp specs, but I have dropped the main down to 150 and adjusted to the point of the engine making more heat and no more rpms, so I'm thinking the problem lies elsewhere.

The ski hits good off the bottom, but just will not rev. We've switched out the entire e-box for a bog stock sxr that runs perfectly, but we have the same issue.

I've checked all the obvious things, but am open to suggestions.

Anything come to mind? Prop pitch is the one thing that may be an issue, but I would have thought that the hooker 11/17 would still turn more rpms than this.

Cheers.

Leigh

 

[Bigfish]

Might check the pitch we had the same thing going on with a sj turned out it was the prop .It was a brand new one that was marked wrong.Also may be the amount of water going in the pipe .

 

[djkorn1]

Put on a stock prop and see what happens... What are the stock RPMs?

 

[Watty]

Will check the water in the header pipe, but last time I adjusted it was 1/4 turn open on the bottom and the top and middle closed.

I think stock rpms are around 7000 but without the top end revving its a pig to ride! I thought it may be an electrical problem, but prop pitch is the only thing I keep coming back to.

 

[Scorn800]

I'd say prop pitch or exit nozzle size?
Box stock sxr's rpm is between 6600-6800

 

[Watty]

Yeah, leaning towards that myself. I don't think I've seen anyone running this pitch in an sxr before, but then again, this is a new Hooker prop from Impros.

What should the nozzle be bored to? I also forgot it has a stubby pump cone...anodized green, I'm thinking it might be Blowsion.

Thanks for the help

 

[X2Pilot]

I would start by taking the stubby cone out and reinstall the stock cone.

80mm reduction nozzle is good.

Was the flywheel on it prior to the revving issues?

 

[Watty]

Ok, here's a new twist....

Even when it is free revved out of the water, it still won't rev past 6k.

It doesn't seem to be hitting a limiter either, so I'm now thinking it could be a fuel delivery issue.

The flywheel was fitted about a week ago, but as it isn't my ski, I'm unsure if there was a problem previously. I seem to recall a timing issue with some flywheel brands, but I haven't been able to find anything.

 

[X2Pilot]

What happened with this? Was it the flywheel?

 

[Watty]

Ah...turned out to be the fuel filters...

They were a brass insert style motorbike filter. Changed them out for some bigger ones and away she went. It was funny as it would only rev straight to 6050 and that's it. I thought it would lean out the mixture a little, but seemed fine. I haven't put the tach back on it yet, but I think it has a lot more in it. Pretty sure it's still rich on top now.

 

[Shonuff]

Had a similar issue when my TBM flywheel hated my 2003 electronics.