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Engine Rebuild - Parts and Things to Check or Measure?

Posted: Mon Dec 28, 2020 3:52 pm
by Greenhorn
Hi All,
The wheels, hubs, frame are coming along so I'm beginning to think about the engine.

Looking at "Pre-Packaged Kits and Assemblies" for sale there are lots of options from basic Engine Gasket Sets and Packages and Clutch Rebuild Packages to Lower End Rebuild Kits, Engine Piston Assemblies and Engine Top End Assemblies.

What should be replaced as a given and what should be checked and measured (piston, crank play, bearings?) I would say engine has not been run in many, many years.

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I've got this to work with, which includes measures....

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Good book to use or is there something better?

Thank You

Re: Engine Rebuild - Parts and Things to Check or Measure?

Posted: Mon Dec 28, 2020 5:14 pm
by thrownchain
If you get your parts from Terry, get the #281 rebuild kit, then order the correct piston you need. That will cover everything outside the crank, order the clutch kit and kick roller upgrade if you need it.

Re: Engine Rebuild - Parts and Things to Check or Measure?

Posted: Mon Dec 28, 2020 6:54 pm
by viclioce
I’m with Thrownchain. Bottom end rebuild kit with seals, bearings, gaskets and new screws. A piston kit for a top end rebuild.

If you’re not sure what size piston to go with, look at the top of the current piston. If it’s not got a size stamped on top it’s likely a std piston. If it’s std or .010, determine if the next oversize is appropriate. If it’s a .030 there’s only one bore left in it unless you can find bigger than .040 pistons & rings from someone.

A piston kit should have all of the following;
Piston
Wrist pin
Wrist pin circlips (2)
Top rod bearing
Lower cylinder gasket
Head gasket
Intake manifold gasket
Exhaust gasket

Also check your oil drain plug. Make sure the compression washer is still good.

And, unless it already has the upgrade, get a heavy duty kick shaft bearing retainer. The OEM retainer was pretty thin walled.

Then have the cylinder bored to match the piston and rebuild the bottom end, replacing the bearings, seals & bushings. Order a couple of countershaft sprocket lock washers too. And the counter shaft O ring for the inner shifter case cover.

Bead/ball blasting or vapor blasting will improve the looks of the shifter cover, cases & clutch cover as well as the cylinder, head & intake manifold.

And make sure you have all the parts needed to rebuild your carb. Main & pilot jets, O ring seal for needle valve, the correct needle snd a hood needle clip and confirm you have the correct slide. Also clean, inspect & replace the float needle valve assembly in the carb, snd clean the choke snd it’s passageways. Check where your air screw is set compared with the published norms in Terry’s library for your model motorcycle.

Depending on the exhaust manifold, you may also want a new exhaust compression gasket if not a slip fit exhaust.

Best of luck with your project and keep us posted with questions & progress!

http://Hodaka-Parts.com should have everything you need, from engine & tranny parts to cables & levers! Purchase on line at the website or Call Terry between 10 am & 3 pm Central time! :ugeek: Victor

Re: Engine Rebuild - Parts and Things to Check or Measure?

Posted: Tue Dec 29, 2020 3:37 am
by taber hodaka
the piston is an item to measure. I would not oversize your piston unless it is out of speck or marred and scared(spelling?) that data is in the manual. I like my rings on the tight side of clearance. ------------ Clarence

Re: Engine Rebuild - Parts and Things to Check or Measure?

Posted: Tue Dec 29, 2020 4:27 am
You might want to look into Boring out, and "Bearing Bush" the Shifter Shaft Hole in the Left Outer Case.

This is a Greg Watkins Fix.

Re: Engine Rebuild - Parts and Things to Check or Measure?

Posted: Fri Jan 01, 2021 4:42 pm
by viclioce
I wonder how long those brass sleeves last? Anyone have one that has lots & lots of miles on one to say how long they hold up without replacing? Just curious, that’s all. :ugeek: Victor

Re: Engine Rebuild - Parts and Things to Check or Measure?

Posted: Fri Jan 01, 2021 5:17 pm
by taber hodaka
A lifetime as we ride today. The old one was steel on aluminum -------------- Clarence

Re: Engine Rebuild - Parts and Things to Check or Measure?

Posted: Fri Jan 01, 2021 5:29 pm
by Dale
What Clarence said.
If you service the shift cover as you should then there is no way it is going to wear out in our lifetime.

Re: Engine Rebuild - Parts and Things to Check or Measure?

Posted: Sun Jan 03, 2021 12:25 pm
I guess you could wait until the STOCK (Steel shifter shaft, to Alum. case hole) wears out, then do the Mod. (it is done on the easy to removable Left shifter case.

Re: Engine Rebuild - Parts and Things to Check or Measure?

Posted: Sun Jan 03, 2021 2:40 pm
by taber hodaka
The trouble with that is the foot change shaft wears oblong and that is not good. If you are not going to ride much, it wouldn't make much difference. -------------- Clarence