Fifth gear inspection
 

Hello,

My 2KF has done 52000 km without any major problems. No special noises and almost no oil consumption at this moment.
I am planning a long distance trip (20.000km) and would like to be certain that the engine is in excellent condition. I specially fear the fifth gear problem.
Is it possible to inspect fifth gear without dismantling the complete motor or are there any other very clear signs if the problem is developing? Can it evolve very quickly?
I will certainly replace the camshaft chain. Are there any other maintenance tasks or part replacements I should really do?

Thanks for any advice

Guy

Inspection
 

You can inspect the fifth gear with just the cilinder removed. Then, from the front of the engine, look inside towards the back and you will see the gears. Take a look at microfiches to determine which ones are fifth gear.
However, the clearest sign of worn gears is a sound like a dive bomber when you drive along a concrete wall. If you don not have that, there might be some pitting but your gears wil make the trip no problem.
To reduce load on the gears:
- Never ride below 4500 rpm
- Gear down: one teeth less on the front sprocket, or 2 - 3 more on the back

Other items:
Check the nuts on the crankshaft and balancer shaft and torque them to correct setting. Replace the key on the balancer shaft (this last one: on some bikes this nut came loose, balancer hit the conrod -> total disaster).

Clutch plates ok?
Oil pump ok?
Take some spare seals for the output shafts: original Yamaha, not expensive, easy to replace when necessary.

That's it.

Auke

Auke,

Thanks very much for the advice.
I never heard of problems with the crankshaft and balancer nuts. I suppose I have to dismantle the motor to set the balncer nuts to the correct torque?

Best regards

Guy

No
 

You do not have to dismantle the engine for that (as in: not have to remove it from the frame and not have to take it apart) except for removing the right hand engine cover. It's even more practical to leave the engine in the frame as it gives you some leverage, the frame that is.

Indeed, crankshaft nuts I've never heard of, but I have seen a couple of engines where the balancer shaft nut has come loose.
While you are checking your fifth gear take a look how the balancer weight moves in between the crankshaft halves and then imagine what will happen if it became out of synchronisation with the crankshaft. Yes, ..... that's what I saw.

Good luck
Auke