1997 GP1200 Yamaha for $600 - little speed problem though

frozenokie

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I am going to probably buy this ski tomorrow. Person states the following:

"fine like i have not ran a comperssion check on it so that will be cool to see what it is I have no idea. I ran it on the fourth of july weekend and it ran all weekend except for sunday. i ran it in the mourning and brought it back in for some lunch and fired it back up but would not go over 15 mph. I looked at the jet and clean some mud out of it but did not change. so i dont know if there is junk in the jet drive or not." Also says "it will idle all day but that's about it."

He agrees to a compression check and we'll be starting it on the trailer with a flush hose.

Here's the two photos in the ad.

3n63kf3l45U65P45S1b8v164e0e0c7f8d1f37.jpg


3n13md3p05O45Y25S3b8v4d914972792c1d04.jpg


My first guess of the obvious is that there is probably something stuck in the jet pump or drive, or impeller, or bent impeller with having to drag mud out of it. A quick fluch hose hook-up will tell if it is clogged there too I believe. If those check out OK and the compression comes back OK, what do you guys think this ski's problem is? Think it's a good bet on this purchase?
 

frozenokie

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

Well, I bought the waverunner. I was well taken care of cosmetically, and for the most part, mechanically. However, the #1 piston had lost compression - I mean 0 PSI, #2 & #3 had 90 PSI each. I looked into the piston hole at #1 piston carefully with a flashlight and it was not scarred up or anything. Led me to believe that the rings have siezed into the grooves. It did have many new parts including starter, oil pump, gas filter, impeller, and a complete lower end overhaul two years ago according to the seller. Also had a local dealer rebuild the carbs since the seller mentioned he does not know much about 2 strokes.

Makes me think... why didn't they replace the top end too while they were in it. I guess money has a big factor there, but I also think that by not doing both is what caused the early breakdown of piston #1. I also think that the other cylinders, if in perfect shape, should have around 115 to 140 PSI. Am I right on that PSI?

Any way, I only gave $550 for it and the trailer, so when you add up the cost of a Wiseco top end kit with gaskets, I'm still under or right at $1000. I still think I got a good purchase here since I think that's all she will need. We started it up for about 5 seconds just to make sure it ran.

TIP: When buying used, ALWAYS take your compression tester. At least it allowed me to get a better deal and not just guess that the problem lies in a less expensive place :)
 

Ernest T

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

You'd like to see around 120 psi on that ski for compression. Look for a loose oil line. Yamaha only zip tied them on, so that was a common failure point. Other was lean run from dirty carbs.

Hopefully a new top end will have you up and running. Not a bad deal.
 

frozenokie

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

Thanks Ernest T. The seller told me also that he was taking on water at one point where he then noticed that the rear water feed hose popped off for that very reason you mentioned. I think what happened was he got it a little too hot and noticed it too late. Hence the 90 PSI in the other two cylinders and the downed cylinder was the one farthest from the water feed, or the other thing I found was the oil alignment marks on the new oil pump were not aligned. They were not allowing enough oil to the cylinders which you know as well as I, causes a dead motor, scored cylinder walls, etc. Either one or both contributed to the cylinder/piston problems. So another rebuild is coming soon - nothing to it :D

He said the carbs were professionally done. He seemed honorable enough to believe that statement since he had no prolem telling me it didn't run right. I took it upon myself to prod around the carbs a little after I got it home and it looked really clean and the settings were set to the shop manual.

I also noticed an upgraded intake grate - SWEET!
 

frozenokie

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

Now tapping foot... waiting on the shop to get the .30 over bore work done. Everything else looked to be in great order on the engine and connections. I've used this machinist in the past twicw on outboards and he does a great job. One outboard he did peeled back the transom on one of my boats like tearing a sheet of paper in half :eek:

Will get the GP1200 cylinders back this week, and along with my 760 top end that I'm doing right now too, I'll have this one ready for break-in at the same time - which should be this weekend.

Will post a follow-up on this along with the GP760.

After break-in is done, I suspect it will run pretty quick. I haven't ridden anything this big yet. Does anybody know what the stock speed of these 97 1200's are? My guess is around 70 :confused:
 

tr_guy79

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

I would guess 57-63 (looks like a 3 seater), though it will probably feel faster. For some reason, my yamaha feel WAY faster than my seadoo, even though it isnt...
 

The Rooster

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

Looks like you made a sweet deal there "FrozenOkie" I'd have to agree w/ tr-guy though about the speed. I would think 70 mph would be a bit optimistic. But, I wouldn't run against you. Good luck !!!
 

smclear

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

IMO you should probably see ~60 - 63. I had a '97 GP760 that I very heavily modified. Stock on that ski was ~53. After all my mods I was doing approx ~63 on GPS, not the dream-o-meter. I could easily hang with and/or beat the 1200's.
 

frozenokie

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

Anything above 55 - PLEASE!!! I don't want my wife outrunnin me anymore on her Seadoo GTX :D Yall know how it is - I hear about it from her after we're off the lake :rolleyes:

To boot - I am boring the cylinders .040 over. With the outboard experiences I've had, when making the displacement larger, the ski has more power and a little more speed too. Would it be the same result with the waverunners?
 

smclear

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

Absolutely, my 760 was bored .030 over and it definitely helped. I believe (can't quite remember) I gained 1-2 mph on top end and it also helped the "pull" from a stand still start.
 

frozenokie

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

Sweet! I thought it might be a little better. Will know after tomorrow - taking it to break-in.

Will update...
 

dannyual767

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

I've got a '97 GP1200. I usually ride the smaller, lighter, weaker '94 Raider and my wife rides the GP. I've seen 54.7 mph on gps while riding my Raider. This is trimmed all the way up and me positioned for the best top speed on pretty much glass smooth water. My wife can pull away from me and she doesn't change the GP's trim from the neutral setting. She also won't really position herself for the best top speed. If I had to guess, I'd say she is running perhaps 2 mph faster than me. I really need to get on that ski and trim it up on smooth water and get a real gps top speed. Perhaps I can get closer to 60.

As far as acceleration goes, that GP1200 will just kill the WaveRaider. I found out on GreenHulk.net that the GP1200s were designed more for accelerating around a race course rather than top speed. Seems to fit what I've seen with my ski. Supposedly a pump nozzle from a 98 or 99 GP1200 has a better angle for more top speed. I'd like to try to find one.
 

tr_guy79

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

Is that a purple hull Raider? I forget what year mine is, but it is the lighweight (and very squirrelly ) purple hull 700R, with a stroker kit.

On completely flat water it stomps a hole in my GTS, but in some chop it is only 3-4mph faster. The GTS is a WWAAAYYY better ride though for the inexperienced. The Raider lets you know who's boss every chance it gets...

-Shane
 

dannyual767

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

Yes, its the purple hull Raider with the 80hp 701cc engine. I've owned it since it was brand new and I'm pretty experienced at riding it. I love how light it is and how easy I can horse it around. It will bite you and throw you off if you're not careful, though.

I wouldn't say that mine is squirrelly at all on smooth water. It tracks sure and straight and I love to keep the throttle wide open on those nice, smooth water days. I will agree that the inexperienced will probably prefer to ride a different ski. They go for my GP1200 way before the Raider!
 

tr_guy79

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

From what I have read, the purple hull Raiders are supposed to be good for 60 out of the box. Mine has the stroker kit from the PO, and pulls pretty quickly on a '95(?) GTX with the 3cyl rotax. Figured I was getting 65mph out of it... Maybe not?

-Shane
 

frozenokie

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Re: 1997 GP1200 Yamaha for $600 - little speed problem though

Sweet! I thought it might be a little better. Will know after tomorrow - taking it to break-in.

Will update...

Got the GP760 broke in at last. Runs like it should. Now I have an offer to trade for a tunnel hull boat. I might just take it too :rolleyes:

Now I have my cylinder for the 1200 back with new sleeves and bore/hone to .030 over (.75mm). I'll take a few pics and post them after it's running.

Plan to take it this weekend and break it in. Will update...
 
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