Low end engine rebuild

[4everFJ]

Hi,

This Winter I am taking the engine out to replace the transmission (2nd gear issue and false neutrals...).

Due to time and money restrictions.., I do not plan to take the top apart, only splitting the crankcase (I can always do the top later with the engine in the frame).

Now, since I have the crankcase apart, I will replace different parts so that I won't have to worry about that until many years from now  

I plan to replace the starter chain, and my question is if there are any problems in disconnecting the piston rods from the crankshaft and lifting the crankshaft out, leaving the pistons/rods in the cylinders? Guess not, but just want to be sure that I am not missing anything here..

I plan to do the following:
-Change complete transmission ( I have got a low milage one from a 3YA)
-Install Detent shift kit from RPM
-New starter chain
-New starter chain guide
-New crankshaft bearing planes
-Rebuild starter clutch
-Renew various oil seals

Any other Things that makes sense to do now the engine is open?

[4everFJ]

Anyone? 

[racerrad8]

I plan to do the following:
-Change complete transmission ( I have got a low milage one from a 3YA)
-Install Detent shift kit from RPM
-New starter chain                      (Cannot Complete without complete disassembly)
-New starter chain guide             (Cannot Complete without complete disassembly)
-New crankshaft bearing planes   (Cannot Complete without complete disassembly)
-Rebuild starter clutch
-Renew various oil seals

Any other Things that makes sense to do now the engine is open?

You cannot remove the connecting rods from the crankshaft without a complete disassembly. The rod bolt nuts are on the top of the rod and the cylinder must be removed to access them.

You cannot remove the crank from the upper case half, so you cannot replace the starter chain or guide. You might be able to "roll in" a set of main bearings, but I have found it difficult due to the timing chain being under tension.

If you are going to "rebuild" the starter clutch, I would recommend replacing it with a late model XJR1300 sprag design. Then you never have to worry about the roller being lifted due to oil thickness or contamination.

Other recommendations:
Every oil seal on the case; crank seal, crank blind plug, transmission seal, shift shaft seal, clutch push rod seal.
Replace all three shift forks with late model XJR forks.
Center case o-ring
All three oil pump oil rings
Oil Pump snap ring
Oil pump pick up screen
Clutch boss hub lock washer
Engine gasket kit

Everything mentioned above is in stock at RPM

Randy - RPM

[FJmonkey]

Get the new tougher shift forks and replace all the seals and O-rings you have access to. Clean and paint what you can. If you order parts from RPM then ask Randy the same question, he has built hundreds of these motors and might know a few things about them. It also might help that he was winning races using the motors he built.

[edit] Randy was a little quicker than I was, might be why he wins races. Getting the hole shot...

[4everFJ]

Thank you both 

I have done complete rebuilds of two Kawasaki engines, but wasn't sure what would be possible on the FJ without taking it all apart.

If I take out the camshafts, would it then be possible to lift out the crankshaft complete with pistons? I know this is a rather unconventional method, but I would really like to avoid doing a valve job, etc.. at this time.

Thanks

[4everFJ]

Well, I found this picture of the crankshaft assembly and I can see the challenges doing what I want to without taking off head and cylinders 



Thank you for your help.

[FJmonkey]

It seems like you are going down the rabbit hole but trying not to get too deep. From Randy's comments the project you are considering is more than half way down the hole. Might as well do the complete job and know it was done properly. Well cared for and it will be good for another 30 years.

[4everFJ]

You are of course right.

I just hoped to be able to postpone the top end rebuild, since it can be done with the engine in the frame. Adding the top end rebuild to the job, is a significant increase in cost 

[FJmonkey]

You are of course right.

I just hoped to be able to postpone the top end rebuild, since it can be done with the engine in the frame. Adding the top end rebuild to the job, is a significant increase in cost 

Getting the engine in and out of the frame is not a big a deal as many think. More challenging when done solo. Randy and I had my engine out of my '86 twice. If I recall the best time was under 30 min, maybe under 25 min... Being able to support the engine from below and raise the bike is the trick. Straps to hold the bike up from a hoist or roof rafters is a common trick. So either wait for the full Monty or bite the bullet and get er' done.