Honda Elite 80 Engine swap challenges

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johnritter50
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Honda Elite 80 Engine swap challenges

Post by johnritter50 »

This a great forum I recently have come across. I have done some searching on here and haven’t been able to find answers to a couple of questions I have.

I have a 1985 Honda Elite 80 (CH80) that has 12,275 miles on it. The engine was losing a little power and developed an oil leak a little while back. When one of the engine bracket’s broke, I decided to swap the engine with a newer, much lower mileage engine. (I still have and will keep the OEM engine)
The new engine has sat for about 7 years.

What year is this engine? From what I was able to gather from multiple searches, I *think the engine is a 2005? I am pretty sure I need some new O-Ring/Carb parts. (read further 😊)

(Insert Pic)

After a good carb cleaning (with a sonic cleaner bath); wire connections cut/swap, I was able to get it running and after coaxing to obtain higher engine rpm, I ran it for a couple miles. The engine will idle alright, but will not come up off idle without a shot of starting fluid. It seems to run pretty well at higher RPM, but will no come off idle no matter how slowly I try to rev it up with the throttle.

There is an air leak between the carb and the engine – confirmed with precise shots of starting fluid.
I think there are 2 leaks – where the carb meets the intake boot, AND on the Enrichment Thermal Valve.

The throttle cable from 1985 has a smaller barrel where the cable attaches to the newer engine carb.
 Will a newer throttle cable that works with the newer engine also work (attach properly) to the 1985 throttle twist grip? Or, do I need to obtain a newer throttle grip as well? Or – what else do I need to make the throttle cable fit/work from a 1985 to the newer engine?

Any other advice or things I should know?

Appreciate the help!,
johnritter50
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motormike
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Re: Honda Elite 80 Engine swap challenges

Post by motormike »

I can confirm that the engine serial number is AFTER the year 2000,
but could not determine exact year.
Regarding the carburetor, I should think that swapping the old carb and intake to the newer engine
would be a good option to solve your issues with both air leaks and cable connection.
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johnritter50
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Re: Honda Elite 80 Engine swap challenges

Post by johnritter50 »

Appreciate the help motormike. I considered swapping the 1985 Carb, but the intakes are just a little different on the 1985's, and I would need to find different length bolts to make it work. I think the 1985's also have a slightly smaller venturi....or something like that. The carb/intake was changed in 1986+ from what I could research.
Thanks again, John
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Re: Honda Elite 80 Engine swap challenges

Post by johnritter50 »

Update:
Got a carb kit from Motoprimo in Lakeville, MN - kit was by the company - Balls Out. (if I remember correctly)
Swapped most of the parts in the kit, and it runs like a top. (No air leaks now-which was a contributing problem)
Two notes:
1. I thought I cleaned the OEM Low speed (needle jet) very well, including using a sharp pick down the length-wise of the jet, which returned specs of brass - so I did not think there was hole all the way through the length-wise through the needle jet. The new jet in the kit did have a small hole all the way through. This was a contributing problem - the OEM jet was so corroded; it corroded itself closed. (despite my attempts at cleaning with a sharp pick)
2. I had the slide spring (which is not in any parts schematic to purchase, drawing, service manual, or most videos I researched) in the incorrect location. I had the slide spring mounted on top of the brass/zinc hold down mount, (which has three small screws and holds the down the plastic spring holder) and below the rubber plunger/needle jet assembly.
THIS IS NOT CORRECT. The slide spring goes underneath the brass/zinc hold down mount, with the three small screws and white plastic spring retainer, which holds down the white plastic spring holder, and the spring itself. I am curious to see how much of an impact the incorrect slide spring mounting would have had after fixing the above stuff, but now that I have it correct and it runs great, I am not going mess with it!
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