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Discussion Starter #1
So I bought these two yamaha gp 800s yesterday for 400 bucks with a double trailer. The guy that I bought them from said he got them from a buddy back in 2013 and he just said they didnt run. I figured what the heck the trailer is worth the 400 to me. The skis are a 1998 and a 2001. Does anyone know what I should look into first for as to why it's not running? I have some mechanical abilities but not crazy knowledge. Any help would be appreciated guys and girls.
 

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Discussion Starter #2
Also forgot to mention on the 98 when I hook up the battery the warning light comes on for the dash but that is it and when I hit thw start button it goes off but comes back after I let go of it.
 

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Sounds like a decent deal to me.
Wow, where do you start. First I'd pull the plugs and spray in some fogging oil in,(a tablespoon or so) and let it set a day or so. Then try and turn the motor over by hand at the coupler at the rear of the motor. May have to remove plastic coupling cover.

If they roll over freely then I'd consider trying to start with a bit of premix fuel poured into them. To see if they'll even try to run. But truly after all those years setting they should be torn down inspected and resealed. Rebuild carbs, clean both oil and fuel tanks. Parts are still available for both from various sources.

Can you post some pics? Do you know how many hrs on either ski?

I have both an 01 & 02 GPr 800. They can reach about 55/56 wide open fully loaded. A blast to ride. 1st Pic of 02 on trailer. 2nd of my 01 and my cousin and our armada of skis and boats at my lake house. 4 skis, 2 pontoon boats, and a 1970's tri hull just out of view further up the dock.
 

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Discussion Starter #4
Not sure of the hours but I'm hoping less than my 800 xlt lol. That thing has 231hrs. I will definitely get some oil in those cylinders tomorrow after work. They dont look too bad but they do look like they were neglected alittle bit of their life. To be honest I am not sure too much about inspection portion of the motor too much but I'm assuming it cant be too bad since there 2 stroke. Picture isn't the best but this is when I got them home yesterday.

I appreciate you chiming in dave in de. Your help with that xlt did help me a few months ago.
 

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You it took alot of back and forth with the shims. The guy I bought it from definitely screwed me. Once I got further in i found grease points cracking because they were so dried out. But I got her almost back to 100 percent. She Boggs down if you hit WOT all at once but that's it. Just take it slow and you get there haha.
 

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So I went to check and see if the PTO moves freely and on the 99 it does but couldnt get my hand down to the 01 pto but I did pull the spark plug out on them and they didnt look that good at all sadly. I'm gunna try an take the stinger pipe off and get to it to see tomorrow.
 

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So Dave here is a good question for you....the 99 has 119 psi up front and 122 on the back, the gauge says 35.3 hours, how would i check to see if that is really true? the hoses for the oil and gas are all hard and everything so i am going to replace them all.

the 01 gauge says 37.5 hours but i didn't really check compression on that motor because there is a bunch of water in there and they guy i bought them from said they have been sitting a long time so i am guessing that the motor or crank is bad but Im not sure, any tips what to check next before i go ripping motors out or is that the next best step?
 

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Sorry so long, haven't been on much lately. Anyway, let's deal with the 99 first. there's no real way to confirm hrs. With 119/122 for compression it should at least run. There a bit low but not bad. 135/140 on new cyl. The good thing if those are true hrs there is a good chance they still have nikasil cyl's.

I'd say rebuild carbs, change the oil and fuel hoses, new fuel filter. With having been setting it would be nice to clean both the fuel and oil tanks but that would require pulling motor out. At least flushing it with fresh fuel would work for now. The only other thing I think I would do is pull the head to check cylinders and Piston condition. This can give a bit of an idea of motor condition. I'd only just get it running and see how well it wants to run. All this still leaves a big risk of a crank seal leak witch could destroy it all rather quick.
With setting all those years the crank seals going to be hard. the best bet will be a full reseal and fresh rings. Power valve wave eater clips. Then you'd be good to go.
It boils down to this spend a bit see if it runs. Then make the decision. What you want to do from there. But if your going to keep it I recommend a full reseal.
 

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The 01 I'd pull the exhaust off at the upper and lower coupling and pull the head and PTO cover. That way you can turn it over and see what you have. But in reality it will need a full pull down to be freshened up as well even if it all looks good. Just because of the time it spent setting.

But I'd start with just the above and go from there.
 

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On the 01 if that water is inside the motor then a full rebuild is do as the crank bearings will have rusted.
 

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Discussion Starter #12
Thanks Dave, I pulled the carbs off today after I figured out that the little Allen key bolts were holding it haha. But hopefully I’ll have them rebuilt by Friday since I’m off and plan on getting the 99 to at least fire one time. The 01 I took the head off and it doesn’t look too bad to me but I am honestly not sure what I am looking at if we’re being honest. Also any idea what the whiteish looking stuff is on the motor and carbs? It’s on both machines and I have no idea what it is. Thanks for all your help.
 

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The pic of the cyl's is the 01?
The cyl's look in good shape but motor will need a full build. The PTO cyl shows a mess of rust residue so the crank is surly toast.
The white looks to be mold scum. I suspect that ski set out and leaks water around the seat front. I think it got very full of water. Probably up to the top of the motor. Definitely above the carbs.

Makes me wonder about the 99??? Can you post a few pics of the carbs and motor of 99?
 

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Hmmm so maybe the motor might not be worth fixing I’m guessing depending what it looks like under the jugs? I didn’t take the cyl cover off the 99 but I do have a pic of the engine bay. I can get one later. I did take the carbs off the 99. The inside of them looks almost like a soft jello type substance. Guessing it is old gas maybe.
 

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I would go a bit deeper from were your at. If you remove that aluminum plate that the carbs mount to and the reeds cages below that. you'll be able to see the crank through the opening and determine if water has been in the motor.
 

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Oil is a good thing. Yes it should be there and is a good sign in this case. as it proves no water intrusion. You should be good to go on this one.
 

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Discussion Starter #19
thanks Dave, I actually got the 99 to fire over today. Man did it smoke a lot but it was a great sound hearing that thing fire up. Now it’s time to see about that 01.
 
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