hi all, i need some help, i rode my 2001 gp1200r over the weekend and it suddenly cut out on me, it started again but would not rev over 4000rpm, and sounded like it had a misfire. i took it to the yamaha dealer who did a compression test and said the 1st cylinder was only showing 40psi, the other 2 were at 110psi. he recommended a complete engine rebuild, both top end and bottom end, ie new pistons and a new cranckshaft. does this sound like the correct advice and would i need to do both? the mechanic said i could just to the pistons but more than likely in a month or two the crankshaft would break as well, if i dont replace the crankshaft at the same time? any advice would be greatly apreciated, thanks

Without knowing more about your ski, it is hard to say what happened. How many hours do you have on it, what modifications have you done, did you take on water, bad gas, and so on?
I would guess that either your oil injection line came off or you dropped a power valve. Eitherway, you need to do a top end on those cylinders and depending on how many hours you have on it, you might as well do the 3rd cylinder. As for replacing the crank, it would really depend on what caused your failure, what internal damage came from the failure, and how many hours you have on the motor.
If the dealer is going to do this, get your wallet out. If you are machanically inclided, you can do it yourself. If you are not, I would find a local "tuner" to do it for you. Depending on what part of the country you live in, there are several good people on some of the forums who could help you out. I do not know of any who frequent this forum, but on the greenhulk forum, there are tons.
Good luck and drop me a line if I can help.
Kirk

Ouch!

sounds like 1 cylinder had a failure - so as a minimum 1 cylinder / piston / rings will need replacing

the cylinder head may or may not be damaged it will need to be inspected - easy to do - remove it and take a look

when a piston fails like this little pieces of metal get in the bottom end - overtime they can play havoc to the motor - so the safe thing to do is remove the motor and dismantle it and clean out the bottom end

when reassembling the motor you will need new crank seals - most people would not replace the crankshaft or the cases unless there was physical damage - most times there is no damage so most times the crank and cases don’t get replaced

next

you need to find the source of the failure

could be multiple things - a good mechanic can in most situations find the cause by looking at the parts that failed

see above post for a couple of the more common causes (power valves or oil line)

where are you located?

as already asked, how many hours on the motor?

do you want to do the repair with new parts or used (used are 50% cost of new)

using used parts this is probably a $1500 repair

new parts $2000

you (probably) don't need a complete motor rebuild which would be $4000 to $5000

anyone mechanically minded can do the repair

sometimes it is difficult to find the source of the problem - so sometimes you need an expert (a good Yamaha Mechanic) to inspect the failed parts to find the cause - you have to solve the original problem or it will just reoccur - you can't tell what the problem was until you tear the motor apart

hi guys, thanks for the replies, the motor has 160 hours on it, i bought the ski 2nd hand with around 110 hours on it, this was about 18 months ago and it has been bulletproof until my last ride. it is totally standard and has no mods on it at all. on the day it broke i has only ridden about 5 minutes when it stalled on me and it restarted immediatly but didnt sound right, so i took it out the water straight away.as for your question about the parts, will 2nd hand parts be as reliable as new? thanks again for the help, greg

where are you located? maybe we can refer you to a good shop

if you are close to Riva you could take it to them

the head needs to come off and the motor needs to be inspected to determine the extent of the damage and to see if the cause can be identified

used parts if in good shape are fine, many shops won't touch them because they usually offer a warranty and they won't / can't warranty used parts

That happen to me in Oct with my 2001 Gpr only it took out the middle cylinder and crank plus it blew up the stator. Cause. it was in my carbs they had bad diaphragms ran the motor lean. funny thing is my motor had about the same hours and it was my second motor first one blew at 35 hrs. Now its the bad thing cost me 4500.00 to have it rebuilt. I dont have the time or tools to do that kind of work, so i payed a shop. I'll try to keep it one more year because its all new again i had all new rings, crank bearings and carbs rebuilt plus new oil injecion pump. It even blew out the stator which the shop told me that it does not happen that offen on that unless you get alot of water in the hull. and i told him i never get water in the hull just oil from the side draft carbs so how would that of happen, just lucky i guess. Just wish it would of held together long enough to trade it in. now i have to keep it one more year now that i waste my money on rebuilding it. The shop wouldnt trade it blowen up. So if anybody wants to buy it Ill sell it for 4500.00 its what i have in it. no trailer. just GPR.