Hey guys...... For a top end rebuild [pistons, piston rings, bearings, pins, and circlips] can one expose these parts by removing the cylinder block completely? If so, what should the nuts be re-tourqued to when re-installing the cylinder? Also, as a check, what should the head nuts be torqued to?
Another thing... For a RIVA Stage II GPR engine, what is the maximum engine operation hours for top-end rebuild and maximum hours for a bottom-end rebuild [crankshaft, connecting rods + bearing, main bearings and seals]? I'd really appreciate soem help....peace
-M3 PILOT-

if you are going to do this yourself, get a service manual. it covers everything, torque specs, the correct way to disassemble and assemble
parts requied......you get the picture. i've worked on engines since i started racing and i would always get one just to make sure.....

Well, if your flush with cash, I'd tell ya to pull the entire engine. Send the crank to RAD for inspection/true/weld. It'll give you a chance to lap the flywheel to the crank nose. If the cylinders are in good shape you could proably get by with just cleaning them with oven cleaner in order to remove the glaze and allow the rings to seat.

Man your playing a game now, when you start making real mods to these things, anything can happen.

take this piece of advice: If you have stock jetting on that stage2, you should really re-jet those carbs.

how many hours you can get out of an engine is anybodys guess. My best estimate is that you'll get about 200 hours out of the top end before you'll need/want to do a top end job. Most seem to be doing it at around 150-200 hours. Crankshafts???
No way to tell, it may be bad right now, it may run another 300 hours.

How many hours you got on that new ski?

To MXVET1: thanks for the input....can i get that manual from the yamaha dealers???

To JetEd73: thanks alot for the input....my jetski has about 40 hours on it....it is not much but my luck has been bad with my skiis and i'd preffer to check and or change the top end and possibly the lower end depending on the lower ends cirumstances. As for the carbs i have re-ketted them...i made the mixture richer mainly becaue it has become colder out here and because i want to have the little extra bit of lubrication int he engine with the wider carbs...


Thanks alot guys i appreciate it

-M3 PILOT-

If you have a GP1200R, it is just getting broken in. I would not even consider doing any major work on the motor yet. I asked when I should look to do the same work to my ski on this forum with 150 hrs on the ski, and was told, as long as the compression is good, power valves were in good shape and updated to leave it alone unless you are going to a big bore. I would rather use the $ for gas power valves, CDI, a couple of impellers and pumps (to quickly change props), triple pipes etc. But then again married with children kind of slows the reality of my wish list.

hahahahahaha.....its all good bro.....thanks for the input.....as for my jet ski it is a RIVA STAGE II GPR....the reason i want to a top end change is because i feel there is something wrong....i dont live int he USA...i live in the UAE (United Arab Emirates) where dealerships and garage's for skiis aint to professional...it is DIRT out here....i have checked up on my jet ski with some places out here and they always say the original OK....so many time they have said OK and s**t goes wrong.....that is why i wanna change it but thanks for the input...i appreciate it...peace
-M3 PILOT-

OH by the way......if i should not do a top end rebuild...should i atleast change the piston rings??????

sorry to hurry you guys on my post but i need to know soon......if i should not do a top end rebuild considering that i have only 40 hours...should i atleas replace the piston rings??? thanks
-M3 PILOT-

If it's not broken, don't fix it, I wouldn't think rebuilding a GPR top end so early, at 40hrs it's just starting breathing right I'd pull the head at 100hrs for the peace of mind, but that's it.
Now about the crank, sounds to be the lotery.
11

11's right and get a service manual and vs yourself before u make a mistake, because these 1200 parts aint cheep. heck u might as well just pull engine out and true the hull. i just finished mine a week ago. i'm very happy with results. just think all that power u are talking about get ya a race finished bottom by truing hull and u will be able to enjoy full effect of your stage 2 gp1200r yamaha.

good luck

Pull the head have a look, if it looks good, dont touch it, if it looks bad, touch it.

Cylinders are easy to take off. Yes you can expose all you need for a top end build by removing the cylinders.

But once you have the heads off, exhaust off, you are only an hour away at the most from removing the whole engine (carbs and engine mounts).

The key is not to removing all these things, any monkey can do that, it is putting it all back together that is extremely important.

Get a shop manual, get the right tools and tkae your time.

I take 2 hours to pull my motor from the ski (pipes, carbs etc) and pull off heads and barrels, flywheel cover off etc. I would take 5 or 10 hours of meticulous care putting it all back together.

Cheers

Peter

P.S I need a holiday, emirates sounds good, you pay for my airfare and I will come over and do it for u for free. Might even bring the bag of "tuning secrets" too.

Cheers

Peter

to see if you need to change the rings, you need to measure the ring gap - decribed in the shop manual

but the cylinders are plated so you can't just install new rings - I think the cylinders have to be honed first - I only have 90 hours so I haven't had to do this yet

but because the cylinders are plated the rings last around 200 hours - so the best advice on this thread has been

"if it ain't broke don't touch it"

chances are if you do all this work something will get messed up and then you will have a real problem - you will strip a thread or something else and then you will be wishing ...........

Mine started running real sweet at 40 hours last year, leave it alone!

quote:

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Originally posted by M3 PILOT:
OH by the way......if i should not do a top end rebuild...should i atleast change the piston rings??????

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quickest easiest way to determine if your rings are worn is a proper compression test using good equipment. If you compression is down pull the top end apart and measure the ring end gap in each cylinder (without the piston in the bore)to determine if your exceeding max ring end gap per the service manaul as mentioned my Phillip.

Based on my experience with over 325 hours of GPR ride time, I'd say you should be good to go for at least 100 hours with a lightly modified GPR. Higher compression will wear your rings quicker than stock compression.

Leave that engine alone !!!!

I did 250 hours on my 2000 GPR, and very hard wearing useee !!!

I opened my engine fo a rebuild when I went to triples !!

I also know a guy here who just removed his stock pipe and put triples, CDI, Heads etccc... He didnt do nothing to the crank or flywheel. It is still running fine !!!!!

BELIEVE MEEE!!!!!IT IS JUST A MATTER OF LUCKK !!!

nice....thaks alot guys i truly appreciate this input im getting.....i will opent he engine and just check it out.....sine all of you say LEAVE IT ALONE i guess i should LEAVE IT ALONE!!!! but again thnaks for your input...
>>>>TO BLUE_78.3_GPR.....hahahahaha....you wanna come to the UAE!!!....where do you live.....the emirates is great now...the weather is great and we have beaches that are unbelievable for jetskiing....are you a certified professional for doing such jobs cause i seriously need a mechanic who is truly experienced not like these f**** here who dont know a towel from a piston!!!!
PEACE
-M3 PILOT-

i also agree, 40 hrs. is barely broken in..
the only thing you need to do now is to make sure your power valves don't puke. i have 90 hrs on mine and won't even consider a top end until 150+, then it will be rings, pistons, top end bearings, fresh head gaskets, clean and match the ports and MAYBE a minor rejet. not running right ?
top end, mid , low end? could be just the gas you are using.......

Thanks for the reply mxvet....as for the TOP END....ummmm....acdording to all the replies i got...i dont think im gonna do it anymore...it might be the powervalves after all....im gonna buy the RIVA Gas-Powered Performance power valves and some other stuff....for now we'll put the Top End rebuild aside for another say 100hrs ....thansk for all your help guys i really appreciate it....peace
-M3 PILOT-

M3 Pilot,

You got to take those cylinders off to do the gas valves anyways, might as well have a look while u r there.

Cheers

Peter

M3,

You don't have to pull the cyl's to install the Gas PV's. That was the original method.

Get the bolt kit (it plugs the shaft holes) from Carl at Island and your good to go.

Gary