Yamaha Yzf600r Thundercat gearbox fix thread

[supermancss]

Ended up buying a new car so the bike took a step back, Will be getting back onto it this weekend and hopefully getting the engine out fully!

Bench picture

Sturdy as a rock!

[supermancss]

few issues with taking the carbs off. Cant get my fat hands or fat head to see where the allen holding the clasp on numbers 3+4. (far right and right center)

tempted to just lift the engine out with them still attached and then take it off if required after ive got the engine out??

Any issues with doing this, ie damaging the carbs or anything else if any spilled (presuming there will be fuel still in the carbs.)

Thanks.

[njl]

There will be fuel in the float chambers at the bottom of the carbs. The main issue would be clearance / access to lifting points when removing the engine - I would say if you are happy they are not in the way or will get damaged when hoisting the engine out they could stay in place. Make sure all the lines and cables going to them are detached before seprtating of course.

The fuel in them will gum up over time. Going over into other angles while engine out may let some of the fuel run into the top end and thin out the engine oil. Given what you have coming up that'll be changed anyway. There should be drains on the bottom of each float bowl if you want to drain the fuel out of them first.

Once you have them off the engine of left on with the airbox off get some plastic bags, or paper towel to fill the openings (venturi?)'s so any dirt or dropped nut, washer etc doesn't go find a new home near your inlet valves or top of piston.

[stretchie_]

Alright Ash, how's it going?


Don't forget I have stuff I could bring around to help you out, like a rattle gun ; )

[supermancss]

Engine out :


Carbs off:


Bottom sump casing off for a sneak peak:


F*ck. Gears completely nackered and snapped to pieces, no idea what has caused it!!
Pieces of the cog that I managed to scrape out the bottom of the sump.




Anyone know if this is worth repairing, should that be the only part thats damaged?

[NiteW4tcher]

ouch would it not be easier/cost effective to source a new engine? and just drop that in

[Jon_W]

Ooooeeerrrrr...... that looks nasty.

You'll have to take the sump off to fully assess that. If the damage is only there and the gears are easy to source then I'd repair. If not a new engine gearbox is your best option. Just check that this isn't a known weakness with these as you could buy another engine and find it's lunched!

Bet your learning loads from this though!!!

[supermancss]

Started last night to strip top of the engine down. I will take to pieces before thinking of buying any other parts. Got a manual to help take apart and few kind offers should I get stuck!

[supermancss]

Down to splitting the very last cases. I can't get it apart. I may have missed a bolt but can't find number 19 from the lower casing.

[supermancss]

Finally got the bugger apart.

Pictures of internals:

http://www.picoolio.com/show/57101/5ayc5

Not sure if this link is working?