Thread: Yamaha engine survey.
06-25-2007, 05:02 PM #1
Yamaha engine survey.
Yamaha engine survey.
I have seen so many engines fail mostly on the 1200pv ski's, My question is as follows:
What model ski:
What year ski do you have:
What were the hours when your engine failed:
What was the cause:
What did you do to repair it:
Please answer as many of these as possible as I am trying to get an idea of these problems and maybe a pattern of what ski's fail the most and why.
06-25-2007, 05:16 PM #2
- Join Date
- Jul 2006
- West Bend, WI
Not sure on cause yet, I put on some bolt on go fast parts, K&N flame arrestors, pre-mix conversion, primer, ADA head and domes, solas impeller, ride plate, intake grate. Since the rebuild I've also got SBT rebuilt top end .05 overbore I believe
Rebuilt the engine's top end with the SBT kit, thought it was fixed, the shop that did it (Glenn Curtiss in West Bend - AVOID LIKE THE PLAUGE) f'd it up so after 5 hours the first two pistons burnt again.
Doing a leak down test to find the leak in the engine and kill the gremlin. Should have back this week.
06-25-2007, 06:46 PM #3
One reason that Im very aware of are oil lines backing off thus causing seizure. I personally had it happen to me, happened to Kirkf350 and also my brother in law all in about 3-4 months from each other. Go premix on these motors to eliminate that from happening. I think running a could oil such as Amsoil is a must!
06-25-2007, 06:53 PM #4
seems so far to be limited to the 1200 mostly, how many 800's have went down...maybe we will get some post.
06-26-2007, 09:18 AM #5
GP 1200 R
I own a 2001 GP 1200 R and at approximately 158 hrs. the third oil line came off at out of all places mud bug 2...... anyways pulled the head off at MB2
and saw a slight seizure on the third and it wasn't too bad....The fix was to just remove the 3rd cylinder and re-weld and nikasil plate to oem specs.The piston I purchased was matched to the cylinder and I replaced the washers, bearings,pin, etc...... checked to make sure the crank spun freely, looked for debris and used a wet vac to suck out any potential debris from the case.
The outcome was good and no problems since then.I bought the ski new on 4th of July weekend in 2001 and no other problems.I use Yama-glue oil and the cat is gone of course and I have never had any power valve problems and I didn't even install the wave-eater clips until 2004.
06-26-2007, 01:12 PM #6
2000 gp1200r I bought it used and broken @ 143 hours
#1 power valve dropped and stoped the piston. ~ 143 hours Put the waveeaters on and new topend.
#3 had a problem before I got it, left some head damage don't know what caused it.
06-26-2007, 04:47 PM #7
not to bad, so far around 100 hrs some minor problems but I dont see a patteren yet. Please keep posting.
06-26-2007, 04:56 PM #8
- Join Date
- May 2006
I have a 2002 1200r. Everyone I know with these skies has blown up. Mine shot the crank through the case. Luckly I was still under warentee at the time. It happened at right around 100 hours. Engine was STOCK. I know of around 5 others that did the same thing.
06-26-2007, 05:52 PM #9
Two failures last year at about 170 and 180 hours on a 2000 GP1200R 1390BB. First one oil line came loose from oil pump - switched to premix (something I swore I'd never do), got a new piston, and sent the jug to Millennium to be re-nic'd. Second one the ski suffered massive water ingestion and taco'd the rear connecting rod - new true and welded crank, two new pistons, one cylinder re-nic'd and a muratic acid wash and honing on the other two cylinders.
The oil line coming off was my fault, I made the mistake of not disconnecting then reconnecting the oil and fuel lines when I moved the carbs aside to install V-Force reeds. The water ingestion was from a friend accidentally switching off the bilge pump while out jumping waves. A very bad idea when the bilge siphon has been removed! It's the second ski of mine the guy's managed to kill, and I'd be pissed except 1) he's a good buddy and 2) he bought the first ski from me after I fixed it up.
06-27-2007, 02:22 PM #10
- Join Date
- Jul 2006
- Acworth, GA
Engine #1 Failed @ 205 hours, detonated #2 piston carb had worked loose. Rebuilt top end with ProX pistons and 1 new cylinder. Carbs found to be clean / good condition (not rebuilt) oil injection was retained.
Engine #2 Failed @ 240 hours (35 hours on rebuild), leaned out #1 piston, but never found a "smoking gun" for the cause, carbs pretty clean and in good condition, crank seals "not great" but not horrible either. Repair was a full rebuild with one crank bearing replaced, all new crank seals, carbs rebuilt, converted to 40:1 premix, and t-handle carb adjusters.
Engine #3 Still running @ 287 hours (47 hours on rebuild), currently is too rich at idle and running 40:1 premix, but I'll likely go back to injection after this season and lean out the idle a touch. Low speed adjusters are impossible to get to with the stock airbox in place.
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