TRANNY REPLACEMENT Sportbike Resource Center Discuss TRANNY REPLACEMENT in the Motorcycle Discussion forums; Originally Posted by LeeFL2 In other words, the tranee is not replaceable since it is an integral part of the engine block. What you end up doing, is removing the ...

[Scudman]

Originally Posted by LeeFL2

In other words, the tranee is not replaceable since it is an integral part of the engine block. What you end up doing, is removing the drive shaft and output shaft, disassembling them, replacing all the bad components and finally reassembling it.

My bad on the cylinders, they are integral to the upper portion of the block!

That is an expensive repair if you need new cylinders. Whole upper case! They could have made those bolt-ons. Much cheaper and easier to RP. Like this Yamaha WaveRunner engine I rebuilt:

Notice that cylinder 1 failed due to an oil injection line that came loose after three years causing the cylinder to loose lubrification and seizing



Here's the new piston installed.



Here's the cylinder, $137 each. Cheaper than replacing the whole case.

I hope you looked that the main bearing as most of the aluminum from the piston went through it and it may fail soon (common 2 stroke problem). As far as the cylinders being part of the block, it is a good design since 4 strokes do not have the pistons fail as often as the two strokes. It also eliminates the base gasket which is prone to leaks due to differential expansion between the case and cylinder block.

[LeeFL2]

Originally Posted by Scudman

I hope you looked that the main bearing as most of the aluminum from the piston went through it and it may fail soon (common 2 stroke problem). As far as the cylinders being part of the block, it is a good design since 4 strokes do not have the pistons fail as often as the two strokes. It also eliminates the base gasket which is prone to leaks due to differential expansion between the case and cylinder block.

Very true. We cleaned the shavings out as best as possible. Most of them are out. Some dropped to the bottom case. They will sit there forever stuck to the burnt oil residue. This was three years ago and that ski is still running.

Got to rebuild the jet pump on the other on this week (he has two).

I have that same ski. It's a nice machine.

[Bubbazenetty]

No problem Lee. And yes if he incase would damage a piston or liner then he'd have no choice but to replace the whole upper portion of the engine (very expensive and time consuming). The GSXR engines prior to the 2000 year had removable liners (a series of 4), which could be removed in case a damage like a piston seized/liner scorned happened. But luckily for him, only one of the gears in the transmission is worn and possibly one bent/worn shift fork. These items aren't expensive...but the labour to replace them is.

But the main issue of having separate liners in the application you have (wave-runner), is because it's a 2 stroke, and lubrication is therefore a major issue that has to be addressed. Replacement of liners/pistons are a normal maintenance issue in 2 stroke engines. A normal 4 stroke engine doesn't suck in air thru the bottom of the crankcase and keeps a constant oil supply that is pumped into all of the oil galleys and to the bearings surfaces in the engine. Oil spewed out of the bearings gets thrown around and coats all of the other surfaces inside the engine (incl. liners/piston rings etc). Some 2 stroke engines have a oil mixing system/injection system which is what I'm concluding is the part that failed on Lee's project. Other 2 stroke engines require the owner/operator to pre-mix the gasoline and 2 stroke oil prior running the motor.

Anyway...the removal of the engine from your 900RR isn't difficult...and if you have the manual...the removal of the bottom of the crancase is doable. Once inside the engine/transmission I'd recommend you follow the service manual to the letter and reassemble once you're sure you've done things right. Having the work area clean and orginized will make things easier for you. Just take it one step at a time, and before you know it...you'll be done.

Good luck.:)

[LeeFL2]

Originally Posted by Bubbazenetty

No problem Lee. And yes if he incase would damage a piston or liner then he'd have no choice but to replace the whole upper portion of the engine (very expensive and time consuming). The GSXR engines prior to the 2000 year had removable liners (a series of 4), which could be removed in case a damage like a piston seized/liner scorned happened. But luckily for him, only one of the gears in the transmission is worn and possibly one bent/worn shift fork. These items aren't expensive...but the labour to replace them is.

But the main issue of having separate liners in the application you have (wave-runner), is because it's a 2 stroke, and lubrication is therefore a major issue that has to be addressed. Replacement of liners/pistons are a normal maintenance issue in 2 stroke engines. A normal 4 stroke engine doesn't suck in air thru the bottom of the crankcase and keeps a constant oil supply that is pumped into all of the oil galleys and to the bearings surfaces in the engine. Oil spewed out of the bearings gets thrown around and coats all of the other surfaces inside the engine (incl. liners/piston rings etc). Some 2 stroke engines have a oil mixing system/injection system which is what I'm concluding is the part that failed on Lee's project. Other 2 stroke engines require the owner/operator to pre-mix the gasoline and 2 stroke oil prior running the motor.

Anyway...the removal of the engine from your 900RR isn't difficult...and if you have the manual...the removal of the bottom of the crancase is doable. Once inside the engine/transmission I'd recommend you follow the service manual to the letter and reassemble once you're sure you've done things right. Having the work area clean and orginized will make things easier for you. Just take it one step at a time, and before you know it...you'll be done.

Good luck.:)

After seeing this happen to his waverunner, I removed the oil injection from mine and now I stricktly premix, 35:1. Less oil burnt at cold engine and idle conditions. Mine is also modded quite a bit.

[shmike]

Originally Posted by LeeFL2

After seeing this happen to his waverunner, I removed the oil injection from mine and now I stricktly premix, 35:1. Less oil burnt at cold engine and idle conditions. Mine is also modded quite a bit.

35:1

I ran all mine Yammies at 50:1 and never had an issue. Even the Stage II and Stage III 1200R's were running about that. I'd think at 35:1 you'd have a constant blue cloud behind you.

For the tranny problem; it sounds like these guys have you taken care of.

Listen to Bubba, the man can rebuild an engine with hs eyes closed.

Speaking of which, when you coming home?

[Ninjakel]

Originally Posted by shmike

35:1

I ran all mine Yammies at 50:1 and never had an issue. Even the Stage II and Stage III 1200R's were running about that. I'd think at 35:1 you'd have a constant blue cloud behind you.

For the tranny problem; it sounds like these guys have you taken care of.

Listen to Bubba, the man can rebuild an engine with hs eyes closed.

Speaking of which, when you coming home?

[LeeFL2]

Originally Posted by shmike

35:1

I ran all mine Yammies at 50:1 and never had an issue. Even the Stage II and Stage III 1200R's were running about that. I'd think at 35:1 you'd have a constant blue cloud behind you.

For the tranny problem; it sounds like these guys have you taken care of.

Listen to Bubba, the man can rebuild an engine with hs eyes closed.

Speaking of which, when you coming home?

Believe it or not, the original injection was WAY more oil than the 35-1 I have now. It barelly smokes.

The coming home thing went way over my head! WTF??

I'm not the one with tranny trouble, I was just offering unsoliscited advice!

[RUBBERDOWN]

Hey everyone thanks for the help I am pretty sure i can do this i have 2 motors one with no tranny which is why I was curious on this process


FOR ALL

THANKS AGAIN

[AK74]

Originally Posted by LeeFL2

AK is out riding...

...To Lee's house.

[LeeFL2]

Originally Posted by AK74

...To Lee's house.

NO !!!! To the supermarket to buy Fruit Loops. His favorite cereal!