Engine Swap Chaparral g44b for Kohler CH640/CH20

[Rushlow]

So I am ready to give up on the Chaparral, needs some new rings. Anyhow picked up a 20 hp Kohler, now it's time to fashion up some engine mounts and figure out clutch alignment.

Looks like the original clutch will mount to the 1' shaft on the Kohler so lucked out there but now I have to worry about belt size and transmission alignment. Also after some reading I found that I also may need to change the weights in the clutch to get it to engage at the correct RPM.

I am going to take the engine & transmission over to the fabrication shop on Monday, was hoping someone has already been down this road and could help me avoid some headaches.

I am going to use measurements from my old motor to ensure I am aligned to the driven pulley easy part. The problem is I will more than likely have to move the engine further away from the transmission as I need come clearance between them. Looks to be about 1-2 inches.

So the belt will be my biggest problem as I can tell so far, I have no idea what size belt I should have as I didn’t get one with it.

What is the stock belt used with the old G44B's? Figure as I am using both the clutch and driven clutch from the original set up, the belt size should be the same but a bit longer. And of course I want to be able to get replacements so if they aren’t able to order one I might have to rethink the clutch system and replace both along with the belt but a new clutch isn’t cheap so if I can avoid it that would be great.

Figure if I move it 1 inch further away from the transmission will need 2 inch longer belt.

If anyone has experience swapping out engines please point me in the right direction.


On a side note I have g44b with electric start for sale needs rings.

[thebuggyman1]

Looks like the original clutch will mount to the 1' shaft on the Kohler so lucked out there but now I have to worry about belt size and transmission alignment. Also after some reading I found that I also may need to change the weights in the clutch to get it to engage at the correct RPM.

The 2 stroke clutch should fit a tapered shaft, not the straight shaft of the 4 stroke.
The 4 stroke clutch will also engage at a lower RPM (yes, more weight).

. So the belt will be my biggest problem as I can tell so far, I have no idea what size belt I should have as I didn’t get one with it.

ATV and Snowmobile Belts - by Dayco

Figure if I move it 1 inch further away from the transmission will need 2 inch longer belt.

Yes

[Rushlow]

The clutch isn't off of the g44b it's from a Alpine 640 looks like it should fit will know for sure tonight as I should be able to get them together. If it doesn't I might have to do some shopping but fingers crossed. Let's hope I don't need to mess with weights either as it's from the bigger motor.

I will see if I can get my hands of few different lenght belts before I send it in to get the motor mounted. Thanks for the link.

I am trying to reuse as much as possible see what it get's me and then start the swap outs.

Once I am done I should have a few extra parts, carbs, engines and another argo transimission. If anyone needs anything let me know I am in Ontario, Canada.

[Rushlow]

Ok well I couldn't help myself, was home for lunch and popped the clutch off of the 640 no good it's threaded, so back here at work googlein' and found that you can get an adapter from 1 inch keyed shaft to tapered. Has anyone used this adapter?

Tapered Clutch Adapter

I might just be to cheap for my own good, I have all these parts I have picked up over the last few years that I want to make use of but not sure if I am just making more work for myself.

Should I use the clutch off of the 440 and use the adapter to make it work on the 20 hp kohler, knowing full well I might (more than likely) need to rebuild the clutch for kohler to get the engagement right for the 4 stroke. On a side note I have yet to figure out which arms and springs are in the clutch but I am thinking it's going to be more of a job swapping them out then the cost from what I have seen parts for the clutch are cheap.

How do I identify the clutch on my 440?

Or

Just break out the credit card and buy Comet 780 Part# 302405A / Duster 94 C?

206095A - Model 94 1" Bore 1 3/16 Belt | Snowmobile Parts | MFG Supply
302405A - 780 Series Drive Clutch for Land Pride Treker | ATV Parts | MFG Supply


Seems like the primary clutch will be a problem but secondary looks like I will only need to swap the spring out to handle the change in torque from the 4 stroke. $16 dollar spring, Red.

I never like to part with money so if it's time I will waste it!

[Rushlow]

Got Some Pictures


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I have an extra transmission that has SS on the stamp, what does it mean?

[Rushlow]

Well I have got the power plant removed, the engine and transmission mocked up. Ended up getting a clutch with 1/4 inch key way from a Argo Shop in Brighton, On. Also picked up 2 Goodyear Rawhide's while I was there, worked out great.

The power plant goes in this week to get a mount installed. I am going to have them mount it with a 5/8 offset from primary to secondary and then allow for some adjustments after install.

I am going to try the secondary with the normal spring but will know more by the time it's back from the shop

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[Matt O.]

Got Some Pictures


[ATTACH=CONFIG]10929[/ATTACH][ATTACH=CONFIG]10930[/ATTACH][ATTACH=CONFIG]10926[/ATTACH][ATTACH=CONFIG]10928[/ATTACH]

I have an extra transmission that has SS on the stamp, what does it mean?

The SS stands for Super Sport. Back in the day Argo offered a SS model that had a higher gear ratio and was much faster then a normal Argo. They ran a Kohler 399 twin cyl. 2-stroke engine.

Matt

[Rushlow]

The engine is in the Argo

Here are some pictures. Lost of clearance on the oil filter and the tub.

Now all I need is a new master link for the drive chain, a bolt for the clutch and a belt.

Still having trouble getting my hands on a belt that will fit. I need something that is 50 inches long and 1 3/8 inches wide. I have movement in the mount could go a bit shorter but will have to worry about the oil filter clearance.

I am going to swap out the twist throttle control for a four wheeler style thumb control. I have one kicking around.


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