Topic: Splittin' the cases - 500 four

[bryanj]

I suspect that on an earlier build before you not all the rollers were in the bearing and this trashed the bearing, overloading the kickstart gear and causing your problems.

There will be some way for lube to get into that bearing even if it is only "splash" but as i aint got one in bits just now(cept in my lock up) i cant go look

[hummbug]

The job's done! Bike is back on the road and running well.

Replaced:
Both trans shafts - incl. roller bearings
Kickstart mechanism
Primary shaft bearing
All oil seals, o-rings and gaskets replaced new

There's a slight oil leak from the oil pump - s/h one ordered to be rebuilt (new o-rings) and added.
There's also a weeping petcock -  New petcock to be ordered and installed soon. The leak is minimal at the moment and evaporates before dripping. Is the install easily done, I've never actualy done it before...

I've been for a couple of rides and there's a bit of tuning to be done - I've been inspired to rebuild the carbs one day - but ultimately I have my bike back.

Thanks for all the feedback and answers. I'm going for another ride!!!

[supersports400]

Hi,

Wow, what a story, you are really lucky to tell.
Do you have a dirtbike background ?

As for the rebuild, I would certainly check the oil pump for damage.
Some junk particles from the bearings and gears are really hard,
and some small particles found there way between the oil pump gears.

My advice would be dissembling the oil pump and check the oil pump rotors for damage.

You might look here : http://forums.sohc4.net/index.php?topic=65233.msg722266#msg722266 to get an idea.

Jensen

[hummbug]

Thanks Jensen - that's a very meticulous oil pump rebuild! I'll be sure to use it as a guide when I get to mine. There are also plenty of good pics in your post that I could have used in my gearbox work - I didn't have the patience to stop and take pics as I did mine!

I did ride dirtbikes as a kid and I'm sure that it helped to keep the bike upright when the brake locked up that day - it felt like instinct - but maybe just self-preservation.
Where are you in Holland?

[supersports400]

Hi,

It always good to have some dirt bike experience, and sometimes, it will becomes a live saver once.
Once I was trying to avoid an accident by pushing my bike (a Yamaha RD500 LC) off the highway into the wet grass (with 100 km / hr), and I managed to keep it on two wheels until standstill, leaving a trail 10 to 20 cm deep (breaking). Hitting that truck would surely meant instant death. The truck was passing another truck and was coming right toward me on my lane. Sometimes I still dream about it (call it a nightmare).

Anyway, I'm living in Huizen and working in Naarden, so it's the center of the Netherlands.

Jensen