[redneckjeep40]

i bought a wr650lx a couple of months ago. I had to put a new fuel pump and some things that were missing but i got it running. took it to the lake and when it started to overheat i tried to get back to the dock in limp mode. in doing so i wiped out the ringsand it was so hot it melted the thermo switch. i just got done rebuilding it it now has 152lbs compression on both cylinders it is bored from 77mm to 78mm. if i run it on a hose it will run all day fine through the flush and through the hose that comes from the jet pump. if i put it in the water it will overheat within 1 minute. i had ran it on the trailer with the hose off the jet pump quick to see the pressure and it will squirt about a foot or two at idle and when u rev it it will squirt about 5 foot. checked the impeller clearences the were 12 thousands so that look good does anyone have any ideas.

 

[GCwaverunner]

blow through the main water inlet hose that goes to the exhaust and see if there is a blockage in the pump unit. if not it will be in the water jackets somewhere. nothing you can do but pull it apart and find the blockage.

 

[redneckjeep40]

i have had all the exhaust apart the other week thinking the same thing.i found nothing. everything in the jet pump is clear. the only other thing i can think of is that the guy has the timing that far off but it seem to run fine do u think that would be something to pull the cover and look at.

 

[GCwaverunner]

Have you pulled out the pump and checked the water inlet. Id say its not getting any water into the motor. And the flush is after the inlet directly to the exhaust

 

[redneckjeep40]

it all seems open that is what i tried when i ran it with the main hose from the jet drive and unhooked it at the exhaust manifold.that is how i knew i had pressure comming from the jet drive. what i took notice of if u start it with the hose unhooked at the manifold it will start to push water out the port where that the main feed hose from the jet drive goes on the manifold. i talked to someone and they said that it was normal due the the back pressure.

 

[GCwaverunner]

how can you hook it up from the jet drive. Im saying pull the nozzle ands pump vein out and have a look into where the water comes in to go to that hose. If it is flushing from that point ok, then it must be shells or whatever stuck in that.

 

[redneckjeep40]

i put water to the 3/8 hose that come from the jet drive that is how i ran it. it ran nice and cool like that. that is what i dont understand. when i run it like that, like i said above i do have some pressure from the jet drive. like i said if i have it on the trailer in the water with that hose unhooked it will shoot about 4ft out of that 3/8 hose at wide open. is that the kind of pressure i sould have or sould i have a lot more.

 

[GCwaverunner]

So your disconnecting the inlet nose and running water through there. Have you put water back through the pump section to see if there is no blockage in there. I reckon there is a blockage in the little white water inlet grate.

 

[redneckjeep40]

what white water inlet grate do u speek of. so u r saying that i sould have more pressure comming out of the jet pump through the 3/8 hose?

 

[GCwaverunner]

No. Have a look where the water enters the jet to goes to the lines to cool the engine. The main water inlet will be in the inside of the pump vein which you will have to pull the pump unit out to see. You cant see in there with the pump still in. There should be a cap which unbolts from the outside which you can have a look to see any blockages. The thing is that when you run it on the flusher, it seems to get good water flow, so I'm thinking it could be blocked in the only main water inlet which is inside the pump unit.

 

[redneckjeep40]

when u look at the jet drive where r u saying that u think that their would be a blockage i had the pump out and i see a hole after the wear ring, that is where the water enters to go in to the hose, the only thing to clog is at that little hole going through the housing. that is open. i thought that maybe there sould be a little cup to catch the water at that hole to help force it up the hole but aparentaly not

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[GCwaverunner]

There should be a little grate. Sort of like a cheese grater which forces water in there. Maybe if thats not there it may be the problem.

 

[redneckjeep40]

if u look at the link that i above it would be #8 i have that if that is what u r talking about. that helps push the water to the jet drive from the intake grate. but like i said all i have is a hole in the housing after the wear ring for the water to go into but nothing to help catch the water to help force it in the hole in the housing. i am just going crazy with this thing i am about to weld a little scoop onto the housing at the hole to help catch the water aND force into the hole

 

[GCwaverunner]

Thats what im saying. nothing to force the water in there. You should be able to buy the part and bolt it in. if not you may have to go see a wrecker and get that part of the pump unit.

 

[atc250r]

Take look at my thread from last year, maybe you have a similar problem:

1990 650LX Overheating

Let us know what you find.

Thanks.

John

 

[redneckjeep40]

i think i found the problem if u look at the picture from the link at the gaskets it would be #12 gasket. when i bought it it was sealer not gasket when i had it apart it was some what clogged with sealer and i could not get a gasket for like two weeks so i made a gasket and cut the water jacket holes out when they should be close off with the gasket and only have a little pin hole. i will let u all now what happens next week when i get the right gasket in.


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