1974 125 WR Crank Rebuild Issue

Good day...
My 74 125 WR is need of a crank rebuild, and fortunately rod kits are now available again from Vintco. I am a reasonable "hobby-level" mechanic that has raced and maintained this bike since 1975. I used the commonly available case splitting tool to split the cases. The r/h (mag) side came off quite easily. However, "pushing" the crank out of the l/h (clutch) side case was significantly more stubborn. I do have a source to have the crank re-done, but I have concerns about getting the crank back into the cases and the cases back together. The crank "re-assembly" tool assumes the pull-bolt and collett will either thread onto the crank or fit over and pull on the crank nut. My tool will do neither. So...are there any suggestions on how to re-assemble? There is of course the "freeze the crank and heat the bearing" method but I have little confidence that will work. I appreciate any advice. I will NOT try to force anything or attack it with a hammer... View attachment 105032 View attachment 105032

This is the side that the crank was a bit "sticky" in pushing out. My concern is when the rebuilt crank comes back, being able to pull...or push...it back in.
The main bearings are good, as they were replaced < 20 hours ago. I will replace both main seals.

Here is a link to discussions of various Husky pullers including the crank puller:

http://www.cafehusky.com/threads/homemade-case-engine-bearing-pullers.6483/

Although pricey, the Husqvarna crank puller will decrease the amount of effort required to get a job done right without causing damage. You have had your 125 WR for 46 years now - think of averaging that cost over the previous 46 years and the next number of years (including your other Huskys) and it will be well worth the investment.

Here’s an idea that i have used , inexpensive and worked for me . To pull the crank back thru the main bearings i have used some pvc that will slip over the crank ends cut into different lengths . Start the crank thru the bearing , cut a piece of the pvc to go over the crank end and you may want to use a washer between the nut and the pvc . Use the nut for that side and crank down on the nut . When the nut runs out of threads , remove the nut , cut another piece of pvc and repeat until the crank is where you want it to be . I’m sure it’s not as quick as the correct tool but this has worked for me .

I could send you the correct assembly tool. Once you've spent the time to build the crank to the proper tolerances, it would suck to have to put it together with the wrong tool.

Correct! I've sent a p/m via this site...thanks!

Unfortunately for me i didn’t have the correct husqvarna tool available . All that is being done is to pull the crank end thru a bearing which i believe the “mangle “ does also . I’m not putting pressure on the bearing race as the pvc sits against the inner most part of the bearing not the “race” itself . Haven’t had the pvc defowm at all . I have used this technique on my 430 , 500 auto and numerous maico engines without any issues . Chris is correct in that it is not the husqvarna recomended tool but this has worked for me . There isn’t a lot of pressure needed to pull the crank thru but it is a tight fit and does pull thru smoothly . It’s up to you , your build , time and money . If you do use my idea just make sure that the ends of the pvc are cut square .

While waiting for the crank to be re-done, I've been fiddling in the shop trying to configure various pullers and brackets to hold them, etc WITHOUT it being a bodge job. After reading your suggestion...I thought..."Gee...quite simple...and not likely to cause a problem...now why didn't I think of that?" Thanks...

Your very welcome . If you have access to the correct tools by all means use them . But when you don’t sometimes you have to improvise . I didn’t just do it this way and call it good , i sat down and looked real good and thought about it since i didn’t want to damage my own engine either . Anyway , good luck with your build , i’m sure you’ll get it together .

A follow up question...
When putting the cases back together on this era Husky...have any of you skipped the thin, narrow,fragile center case gasket and simply used Yamabond 4? I ask because I have a NOS center case gasket and there is NO WAY that fragile piece of paper will stretch to meet up with the case or fit where the screw holes are. YES I KNOW IT'S NOT A YAMAHA...but it seems to me those precision machined Swedish case halves do not need a gasket to seal...and the thin-ness of the paper gasket certainly serves no "shim" purpose for the crank or the trans shafts. I appreciate any advice...

Those old paper gaskets shrink as they dry out. I spray them with water and let them swell back up until they fit, they may still be alittle tight so a light coat of whatever you use on one side will do. I find the Cometic? Gaskets to be the thinest pos available.

This may help:

https://www.hva-specialty.com/produ...-16-10-684-01-nos?_pos=5&_sid=4cfeee178&_ss=r

Yep...I soaked it in a tray of hot water...was able to place it on the clutch side case half..."pin" it in place with 6mm screws...and it 99% fit...but as it dried it wants to get stiff and shrink again. I have yet to have anyone say they simply use Yamabond, so I think I'll just go for a new...and NOT an old NOS... center case gasket.

Update: New Vintco Rod kit in the crank...all seals replaced...cases went back together fine. I scrapped that old dried out oem center case gasket and got the high quality Cometic from hva-specialty, What a difference...it fit perfectly. Many thanks for all of the good advice.