splitting 3tj crankcases
Forum rules
Please can you post items for sale or wanted in the correct For Sale section. Items / bikes for sale here will be removed without warning. Reasons for this are in the FAQ. Thanks
Please can you post items for sale or wanted in the correct For Sale section. Items / bikes for sale here will be removed without warning. Reasons for this are in the FAQ. Thanks
-
- Settled in member
- Reactions:
- Posts: 49
- Joined: Wed Feb 24, 2016 8:15 pm
- Bike owned: 2x3tj xs650
- Location: Midlands UK
splitting 3tj crankcases
Hi all, I'm new here and I have a question.
Is it possible to split the crankcases to access the gearbox on a 3tj without disturbing the cams, head and barrels etc?
Thanks
Neil
Is it possible to split the crankcases to access the gearbox on a 3tj without disturbing the cams, head and barrels etc?
Thanks
Neil
-
- Site Supporter
- Reactions:
- Posts: 5374
- Joined: Tue Apr 29, 2008 8:59 pm
- Bike owned: Bimota SB6 Yamaha FZR 3TJ x2
- Location: Lundin Taan
Re: splitting 3tj crankcases
No.
You have to remove the head and barrels to access 2 bolts at the base of the barrels.
You have to remove the head and barrels to access 2 bolts at the base of the barrels.
-
- Settled in member
- Reactions:
- Posts: 49
- Joined: Wed Feb 24, 2016 8:15 pm
- Bike owned: 2x3tj xs650
- Location: Midlands UK
Re: splitting 3tj crankcases
Hi
Thanks for the reply.
I've just googled some pictures and I think I see the two bolts one either side of the cam chain.
Oh well I better get a head gasket ordered, the engine is running OK at the moment, I'm not going to change anything there, would it be advisable to hone the bores or will it be OK not to, if I'm using the same pistons and rings?
Cheers
Neil
Thanks for the reply.
I've just googled some pictures and I think I see the two bolts one either side of the cam chain.
Oh well I better get a head gasket ordered, the engine is running OK at the moment, I'm not going to change anything there, would it be advisable to hone the bores or will it be OK not to, if I'm using the same pistons and rings?
Cheers
Neil
-
- Site Supporter
- Reactions:
- Posts: 5374
- Joined: Tue Apr 29, 2008 8:59 pm
- Bike owned: Bimota SB6 Yamaha FZR 3TJ x2
- Location: Lundin Taan
Re: splitting 3tj crankcases
What are you going to ultimately do to the engine, why do you need to split the cases ???
You don't need to hone the barrels if you keep the same rings. Have a look at this thread ... need the end is where I tear down the engine viewtopic.php?f=35&t=38054&p=274374&hil ... et#p274374
You don't need to hone the barrels if you keep the same rings. Have a look at this thread ... need the end is where I tear down the engine viewtopic.php?f=35&t=38054&p=274374&hil ... et#p274374
-
- Settled in member
- Reactions:
- Posts: 49
- Joined: Wed Feb 24, 2016 8:15 pm
- Bike owned: 2x3tj xs650
- Location: Midlands UK
Re: splitting 3tj crankcases
I'm actually picking the bike up in the morning so I'll report more tomorrow but from what I can see in the photos the bearing on the shaft behind the clutch has collapsed.
Neil
Neil
-
- Site Supporter
- Reactions:
- Posts: 5374
- Joined: Tue Apr 29, 2008 8:59 pm
- Bike owned: Bimota SB6 Yamaha FZR 3TJ x2
- Location: Lundin Taan
-
- Site Supporter
- Reactions:
- Posts: 1292
- Joined: Thu Nov 20, 2008 1:09 pm
Re: splitting 3tj crankcases
With a bit of thought you could probably replace it without stripping the motor.
-
- NWAA Supporter
- Reactions:
- Posts: 693
- Joined: Fri May 02, 2008 8:06 pm
- Bike owned: 3TJRRSP TRX850 XV750 cafe
- Location: Hertfordshire
Re: splitting 3tj crankcases
If the bearing has broken up you will want to get the engine stripped and clean out all the shit!
Also best to replace the bearing on the other end of the shaft too.
Check the gears very carefully as it might have chipped a tooth.
Also best to replace the bearing on the other end of the shaft too.
Check the gears very carefully as it might have chipped a tooth.
-
- Site Supporter
- Reactions:
- Posts: 5374
- Joined: Tue Apr 29, 2008 8:59 pm
- Bike owned: Bimota SB6 Yamaha FZR 3TJ x2
- Location: Lundin Taan
Re: splitting 3tj crankcases
Depending on what you want the bike for you're looking at about £350: 100 gaskets; 100 skimming the head and barrels; 35 cam chain; leaving the rest for the bearings fitting and other bits.
Go to a toy shop to get a small sucker thing to grind the valves - you cab use the Halfords ones but the sucker only just fits.
You can use a T'cat manual for the engine build.
Go to a toy shop to get a small sucker thing to grind the valves - you cab use the Halfords ones but the sucker only just fits.
You can use a T'cat manual for the engine build.
-
- NWAA Supporter
- Reactions:
- Posts: 693
- Joined: Fri May 02, 2008 8:06 pm
- Bike owned: 3TJRRSP TRX850 XV750 cafe
- Location: Hertfordshire
Re: splitting 3tj crankcases
I grind my small bike valves in by putting them back (without the springs) in the head then shoving a piece of silicone tube over the stem and pulling up, I even put the silicon tube in a battery drill and go back and forth with that.
It's much quicker!
Just be sure to get all the grinding paste out!
It's much quicker!
Just be sure to get all the grinding paste out!