Yamaha HS1 90 twin lower end build part 2

[@vintubeable]

Thanks Dale for the sequel on the Yamaha 90 twin. Nice insights on the gearbox, clutch and magneto assembly. I think the next video would be the icing on the cake... Piston and cylinder assembly. Looking forward to it. 👍

[@montana2strokeracer]

Thank you, I am getting excited to see and hear it run, working on the cylinders now.

[@usairchairmanpfd2889]

I just want to get an air B&B up in Montana for a month and be your apprentice Dale ;-)

[@montana2strokeracer]

Thanks man, if your ever in the area stop by.

[@douglasmeeker360]

Exciting conclusion to the bottom end reassembly. You've got a nice methodical approach, talking through each step to be sure nothing is left out. I always like to mention that my first bike was a '71 HS1 and it had a B suffix to designate the second year of that model. Thanks for the informative and well produced video Dale.

[@montana2strokeracer]

Thanks Doug, I have not ridden a HS1 but have ridden the YL1 twin jet 100, this HS1 should be faster with the carb slides replaced and since it's a 5 speed instead of a 4.

[@josephsawicki9335]

Man I Love all your videos you are the man ! I am old now but because of you I am going to try and find an old dirt bike and try and find my youth again, Thank you Dale.

[@petermckee1061]

I'm much like you!

[@frankdillon6127]

im 80 and always looking for a old derelict small bike that needs love. have just 2 left that i finished about a year ago. love the hunt on ebay for parts and getting manuals etc, great therapy. trick now a days is getting the price down low as people think the old bikes are worth a lot.

[@montana2strokeracer]

Thank you, Joseph, and good for you. You will have just as much fun now as you did then.

[@donbridgewater2988]

That is going to sound like a swarm of bees, I love the sound of a 2-stroke twin.

[@montana2strokeracer]

Indeed my friend. Might get stung.

[@jamesws3]

Very much enjoyed reassembly of this cool little twin. Very surprised to see such an error in the service manual on clutch discs, but you found it! Excellent insights on the gears and magneto. Look forward to hearing it run!

[@montana2strokeracer]

Thanks Jim, it has been fun and there is a long way to go. Yes, there are a lot of problems with some of the early manuals. You have to be careful with spec's especially.

[@donbridgewater2988]

Good morning Dale, I got my coffe here, now lets see the magic for today.

[@montana2strokeracer]

Thanks for stopping by Don. Much appreciated.

[@johnfry9010]

Dale , this has been a very interesting project , I have never seen a twin torn down like that , Very Cool !

[@montana2strokeracer]

Hey John, it sure is, I have been enjoying learning some new stuff and remembering things that I thought were gone forever.

[@oldgreybeard2507]

Thanks for posting. Always enjoy watching your skills.

[@montana2strokeracer]

Thank you, sure appreciate the support.

[@JohnnieBravo1]

These are fun rides Dale! Thanks for taking us along

[@montana2strokeracer]

Sure, thing Johnnie, they are sweet bikes, this one has great chrome, so clean up and paint will make a nice machine.

[@frankdillon6127]

gee, guys your up and ready for work! Frank Here!

[@montana2strokeracer]

Thanks for stopping by Frank.

[@johnb5519]

I find it amazing that they made a 90cc twin back then. Too bad they don't make them today. And they even put helical primary drive gears in it, unlike some newer bikes made today.

[@montana2strokeracer]

Indeed John, they were very cutting edge at the time. Still, lots of fun. Looking forward to hearing it run.

[@johnb5519]

@@montana2strokeracer Me too.

[@peteetwell826]

Great video on repairing the clutch basket and the installation. Good catch on the clutch plate orientation. Even the parts book can occasionally be wrong. Looking forward to the boring of the cylinders.

[@montana2strokeracer]

Thanks Pete, I have found many publishing errors, bet there are a lot I haven't found too. Cylinder boring video up tonight, Pete. 9/25

[@retromechanicalengineer]

Great work Dale. It will be interesting to watch you bore those tiny cylinders. Best wishes, Dean.

[@montana2strokeracer]

I know Dean, I have got to do some experimenting to see how to proceed.

[@tjs_welding_and_fabrication]

Awesome vid. I fixed my kids kx85 swingarm using machining an insert and milling the bad one out. The tigging the insert in. You have inspired me to make vids on this.

[@montana2strokeracer]

Right on man, sounds like you have caught the bug. Jump on in the water is fine. You will do great on KZbin with your fabrication and machining talent, all you need is your phone camera and some editing software and your off and running.

[@bigmurr725]

Thanks Dale , I did not know about the longer carb slides . My old YL 1 used to rev pretty high . I wish I still had it . Thanks again Dale .

[@montana2strokeracer]

Thanks Murray, yeah that was the way to get the 90 to run as fast or faster than the 100, because it's got a 5-speed transmission also. The twin jet 100's were fast though.

[@frankdillon6127]

hear the geese leaving town, smart move!

[@montana2strokeracer]

Yeah, they don't want to be here in month.

[@cainbeeping8480]

Coming along nicely.

[@montana2strokeracer]

Yeah, going to try to bore one soon.

[@markaddy53]

great job as always dale gettin there now should be sweet as a nut next video please

[@montana2strokeracer]

Hey Mark, getting close for sure.

[@retromechanicalengineer]

Here!

[@ardtessa]

These videos are of much help to me Dale, even when I have a different engine. I thought about setting the shift pawl thing as mine doesn't shift very well, I also thought I got a bad copy of the shifter shaft as I've put a new one in. More thinking watching this made me realize that I made a mistake in making a gasket that goes between the two engine halves of the engine as it was part of the kit I bought. I now realized that there's no gasket to go there but sealant ! Oh well, I guess it needs to come apart again ! 😅 Regards, Ard BTW, what is a good place to get parts from for these older models ?

[@montana2strokeracer]

Woops! we all make mistakes Ard. Just learn from them and move on. Parts? I get a lot from the OEM manufactures, still a lot of parts available. Used parts from Ebay or the local salvage yard.

[@ardtessa]

You might try and put that rubber breather part in some brake fluid for a while. It can make rubber parts swell up !

[@montana2strokeracer]

You are right, didn't even think about it. Thanks

[@richb419]

Hi Dale, good video. is there a reason that you don't bolt the point cam in place before you mount the stator? Rich

[@montana2strokeracer]

Not really, I wasn't for sure it would clear the hole, the AT1s just won't do it.

[@rowlandcrew]

what does it look like inside the oil pump? have you looked into rebuilding one?

[@montana2strokeracer]

I haven't had it apart. I will do an output check once its running, if it passes the test, no point in rebuilding in my view.

[@cainbeeping8480]

What was the manual you were using for the size of shims and O rings?

[@montana2strokeracer]

Its the factory parts manual, I pick them up on ebay, if they don't want too much for them.

[@cainbeeping8480]

Here

[@104ducati]

Good video, thanks. My YL1 (UK) 50 yrs ago I recall had an innovative gear change pattern; if you stopped at traffic lights in top gear you could press the lever again into neutral(!), BUT if riding along you forgot it was in top another 'upwards' change would give you neutral - ah ha- missed a gear?, so try again and into 1st!!!!!!! 💩🩲. By the by, if you want a smaller cylinder bike Moto Guzzi marketed a 50cc aircooled twin in '69/'70, but I never saw one in the flesh.

[@montana2strokeracer]

Thank you, oh yes, the shift pattern on those older bikes can cause a lot of problems for those of us that are now used to the newer pattern, since about 1969 I think. I have to concentrate on shifting while riding the older ones. I have heard there were many smaller twins back in the day. But like you, I have never seen one in the wild. In some magazines I have seen some strange but fast bikes.