1990 SP 587 Overheating

[RodInEscondido]

Methinks you are right on top of it.

The smaller output from the flow divider seems to be pretty open and the service/parts manual does not specify this as being one of the calibrated elbows.

The small connector in the top corner of the head cover just feeds the pee hole on the stern, kinda appears to me due to the small size of it that it is more for an indicator of flow thru the head vice significant cooling. The important output flow is thru the (calibrated #2) connector on the side of the head that then flows back to the exhaust.

Rod's latest hairbrained idea: Pinch off the smaller output from the divider and the top line on the head that goes to the pee hole. Disconnect the hose to the divider from the header and apply some air pressure to the hose ... you should get good air flow to the exhaust output from the hull. Caveat: due to the parallel flow to both cylinder cooling jackets you could have a good flow indication to the exhaust and still have no flow thru one of the cooling jackets.

The head o-ring set for the 91 SP/XP is probably the same (587/yellow engine), you would need to verify.

Yes, starter removal is just gobs of fun. I have needed to use multiple socket extensions and wobbler to get to the bolts. With a recent rebuild on your ski the bolts should not be frozen in. Good time to check/replace/lube the ground connector/cable.

Fun, fun, fun.

 

[Raymond 88]

Okay it looks like we have a solution here. I finally have water coming out of both of the bleed holes on the land test anyhow. Try to get it on the water this weekend to confirm. Kind of figured it out after looking at the manuals from the 1990 Sp 1991 SP and 1993 Sp. It looks like I have a 1990 1/2 SP. Half way through the year they changed the tuned pipe and some of the cooling system components on the SP.
What happen in particular case is someone had changed some of the fittings for the cooling lines on the tuned pipe. After careful examination and about a month of frustration I came across the problem. Previous owner had mixed up the cooling water lines on the tuned pipe. He had the 8mm line from the "t" after the jet pump going to the straight fitting on the tuned pipe. He had the 8mm cooloing line that goes to the lower block divider for the water jackets coming from the 90' fitting on the tuned pipe. The cooling lines should have been the other way around. Changed the straight fitting (he had a 1/2" hose barb instead of 8mm barb) and put on some new hose and switched around. Now we have finally have water coming out of both bleed holes.
Hopefully not to much damage done before we figured this out. Should have a better idea this weekend.
Thanks

 

[IDoSeaDoo]

Rode my GTS (same engine) all day Sunday. One time I opened the hatch and touched the engine and it was scalding hot. Couldn't keep my hand on it but for a split second. I bet it was like 170F. Felt crazy hot, but all the lines were "peeing", even got a nice 6-8" jet from the weep hole in the head at idle. All signs point to the fact that mine is plumbed correctly, but it still gets HELLA HOT!

 

[RodInEscondido]

What ... after all the work we have put into this ski you are going to wait another several days to do the acid test? My expert opinion is that you take tomorrow off work and test the ski. Of course I can say this being unemployed/retired.

 

[Raymond 88]

Hey Rod, right you are. This puppy needs to have the acid test in the water ASAP. Thanks for all the ideas and help with this issue. Once again it looks like it comes down to the information that is provided. All indications are this 587 was rebuilt last winter. Why the guy I bought it from claimed he used the ski for a couple of hours up north at his cottage is beyond me. He said he found it to "tippy" for a 50 yr old and he wanted to buy a bigger ski. Luckily a took a few pics of the engine and all the hoses before i took it apart the 1st of many times. There is no way the machine ran for more then a couple of minutes without overheating in the water. Explains why it ran better with the backflush then in the water. Wish I had known that from the beginning thats all. But I sure do understand the cooling on these 587's now. Now on to the oil injection pump on this unit!

 

[Raymond 88]

Thanks IDoSeaDoo, I am wondering if the guy who rebuilt this engine didn't have the same thoughts about the 587's running hot. He had a 1/4" pipe thread and 12mm nipple coming off the tuning pipe that supplies the water to the engines water jackets. (Instead of the spec 1/8" pipe thread and 8mm hose) You sure would get a lot more water going through the water jackets with the bigger size nipple and hose. I went half way and took the nipple and hose down to 10mm. I can let you know after the weekend what the results were.

 

[Raymond 88]

It looks like we have the problem solved!!! Finally had the 1990 587 out on the water for a couple of hours yesterday. It runs quite well everything considered. Water coming from both bleed holes now. It doesn't have all the bells and whistles of the new skis but there is something to be said for a light little unit that runs good and handles well. Not as many things to wrong on these older units to.
We only have a couple weeks left in the jetski season up here. I am going to try to get through these few hours manually feeding the oil into the injector pump so it doesnt seize up. I connected a 1 ft piece of hose to the intake nipple and am filling the hose up with oil before going on the water to keep some lube going to the injector pump until I can tear it down and get it blocked off. Seemed to work fine yesterday as a temporary solution.
Thanks to all for the help with the overheating issue. It was a great learning experience and the input from the forum was invaluable.