90 SJ 701 running hot week pisser

[undieingbreed]

Hey guys, posting this since I don't think I found my problem yet.
Background, 1990 SJ with a 701 and factory pipe. Always ran well for 2 seasons since I put the 701 in. Last few times I noticed pisser was weak on idle, it was always pretty steady. On throttle it was better but not the 6" stream it used to be. Also running hot, can't hold head pipe or block, and 3 head pipe bolts sizzle and head pipe sizzles when running harder.
I googled and found that it could be.. blocked hoses, blocked adjuster screws, bad head gasket.
I pulled the hoses while on ski and flushed with water and 40psi, found no blockage. Put back together, ran it, same deal. Not running lean, even tried to richen it up more didn't seem to help.
So now I pulled it head, gasket and metal rings seem good, pulled head pipe, adjuster screws, 90s and housing clear, ran paper clip through adjusters too, flushed with water and air. I ran air through the manifold, same thing no blockage, filled jacket with water, water drains out of block right away.

Never had a heat issue with this ski and actually always ran it with adjustment on no sizzle at all.

 

[undieingbreed]

Forgot to mention, always ran on single cooling in and out. With pisser tee on the branch with main line going to the exhaust, always had good stream.

 

[SteveC]

Is the feed from the pump blocked?

 

[undieingbreed]

Is the feed from the pump blocked?

Nope, checked that before tool anything off, posted a picture back feeding from hose can see nice stream out. Also shot 60psi through it several times..

 

[undieingbreed]

I'm

My guess would be that you have a Cylinder Head leak caused by either a warped Head, a bad Gasket or loose Cylinder Head Bolts.

Check the Cylinder Head for warpage.

Those Cylinder Head Bolts should be re-torqued every season.

Hoping that's what it was but the gasket looked to have no carbon marks, metal rings were intact, the head came off with no prying that's all I can hope for as far as it being bad

 

[Harbor]

Jc may be in too something, your rear piston looks cleaner than the front piston, and what you’d expect to see on a leaking head or gasket.. another tell is the pisser starts spitting the cooling water out the pisser (not a constant smooth stream) did you notice that?

Question, was looking at your pics, do you have hose off head going to the top of head pipe and lower head pipe feeding the stinger?

People do run that, but if ( cyl head feeds lower head pipe and top of head pipe feeds stinger area. Then air won’t Potentially get trapped in the head pipe...may want to switch it up after you find your issue... if running it that way

 

[undieingbreed]

Yes I think I did notice a bit of sputtering but I think all my skis have done that till they fill up the bead pipe.
Put it together and took it out today. May be a bit better, head bolts still sizzle a bit but the head pipe didn't today so I guess that's a partial win. Air and water were a few degrees cooler but nothing special.

I do have the head, feed the top of the head pipe then bottom to the stinger yes, always ran like that but people do say to change it. I'd have to buy more gates barricade hose to do so.

I don't visually see any leaks on the outside of the head gasket. Cleaned it best I can without decking it so hopefully that's good enough. Hopefully it seals.

My plugs never had any white residue like water in the oil.

 

[undieingbreed]

Also noticed today that the pistons are .50 over as well. I don't think that would all of a sudden be the issue. But who knows. The plugs looked decently brown no easily visible lean as well.

 

[Harbor]

Yes I think I did notice a bit of sputtering but I think all my skis have done that till they fill up the bead pipe.

Yes ^^^ that is normal...

What I am speaking on is, while riding that it sputters....cyl pressure during combustion escaping into the water jacket has an effect on a normally solid & constant pisser stream

 

[undieingbreed]

Yes ^^^ that is normal...

What I am speaking on is, while riding that it sputters....cyl pressure during combustion escaping into the water jacket has an effect on a normally solid & constant pisser stream

When riding at normal + speed no it's a good stream. I think it was a bit iffy which is what caught my eye and next to no water at idle which was new.

 

[wmazz]

My guess is the impeller's leading is dinged up (a common cause
on all brands).

Oor the bottom of your head pipe has sand or a calcium deposit
slowing down the flow.


Bill M.

 

[undieingbreed]

The impeller looks good nothing bad at least. The tolerance may be a bit loose, maybe 1mm or so so maybe a small part of it. But to happen all of a sudden not sure

 

[undieingbreed]

My guess is the impeller's leading is dinged up (a common cause
on all brands).

Oor the bottom of your head pipe has sand or a calcium deposit
slowing down the flow.


Bill M.

Forgot to reply about the head pipe. I took that off and looked in, took the 90s off. Nothing visible not even white residue

 

[fastgtfairlane]

I know you said you blew air through the manifold but have you taken it off to visually inspect it? It may not be blocked off completely but restricted enough to slow the water flow down. What you might need to to do is run it on a trailer in the water. Start with the main cooling line going into the manifold. Take it off and run the ski in the water to verify solid water flow. Obviously dont run long as engine has no water to it while you're doing this. If you have solid flow, let it cool back down and do the same thing with the line coming out of the head. Between those two areas, you'll find your restriction. It's either coming from the pump or line through the hull or it's in the engine. A riding buddy has a fx1 with dual cooling etc has one line coming off the engine going to hot hands setup. Noticed it started getting hotter one day and a little less flow. Ended up finding a small piece of tree bark stuck in a 90 degree fitting.

 

[undieingbreed]

Yea that will be the next step after the carb. Those two bolts in the middle of the manifold are EVIL 1/10 turn per turn. I was trying to use a paper towel to gauge air flow to front and rear cylinder, seemed the same. Maybe it is partially blocked like you said. I ride in 100% fresh so all it could be is debris of some type.

 

[fastgtfairlane]

Get a dedicated 12mm wrench and grind down both sides of the open end of the wrench and that will make it much easier to get in there