Yamaha Motor Conversion

[crowsnest]

Hello all...Great site!..Sure is some nice carts on here...Here's my dilemma.. A few months ago my fiancee and I bought what I believe is a 1989 Yamaha G2. We decided to restore it with a St. Louis Cardinals theme (I'm a Cubs fan..lol) and give it to her Grandparents for Christmas. The cart is finished as far as paint and whatnot but after completion it developed a noise in the bottom end.(just my luck). After some research and wrenching my friend and I came to the conclusion that it was probably a crank bearing so we decided to do a full bottom end rebuild since it was an older cart and had obviously been rode pretty hard. We pulled the motor to discover that the clutch side cover was wahlered out where the end of the gear's shaft sits inside it on the front gear.(hope that makes since)...It also has a tremendous amount of play in the rod. I'm kind of under the gun obviously beings its so close to Christmas. I'd really like to give them a running cart..not a big paper weight..ha... Ive been searching all over locally for a motor or complete cart to swap motors in that I could afford. I actually have a lead on an older Yamaha G1 pretty nearby that has been completely rebuilt and supposedly run's great.. My question is this..Would it be a reasonably managable motor swap to throw the G1 motor in the G2?..We have some decent fab skills if need be but looking to try to make it as painless as possible for everyone. Any help would be greatly appreciated..

[crowsnest]

I figured I would keep the G1 roller and maybe drop a Snowmobile motor in it or something in the future for myself..:)

[rwt101]

The G1 is a 2 cycle cart and as you know the G2 is 4 cycle. I would say it can be done, but someone on here with more knowledge should be able to tell you more.
Bob T

[DOOmsman]

Is it the balancer shaft that is wallowed out?
If so you can remove it and the cart will still run.

[crowsnest]

Thanks..Yes indeed I am aware that it's a two stroker...Guy came buy and unfortunately we werent able to make a deal.. Ive also found both an old club car and and old Harley cart motor as well. At this point I'm trying to find anything that will fit that I can make work. The part that is wahlerred out is the end of the big gear located in the very front of the case.Ill keep looking...Thanks again for youre help.. Hopefully I will get something in the next day or so..

[sho305]

If you can fab things the cheapest way is get a clone engine from harbor freight or maxtool. Even the 13hp will pull the cart better than stock. You need the clutch adapter from CPP. But you will have to make a mount, fab an exhaust, likely airbox, cables to hook up, etc. There are threads on it here. But you will have a new motor cheaper than a rebuilt, except its a project you will not get done right away. You would have 3-400 into it depending, I have about 500+ into my 420cc clone but had the head cut and ported and put some parts in it, custom made exhaust, etc. It has about twice the power for trail riding and still runs stock clutches and starter/gen.

I have two G9 engines that only need rings far as I know they ran fine but would burn oil and smoke some. They are original engines the carts were bought from a golf course trade in over a decade ago and they have never been touched. But I'm not in a position to do anything with them until next spring they are in storage. I'd like to repair them and sell to pay for the clones....when I can get to it lol. I have too many projects backed up at the moment.

There is no good fix I know of for the side cover wear on the balance shaft, it is becoming a problem on carts with a lot of hours. It will run without the shaft in there. There is no good replacement engine except possibly another 4 stroke yamaha. The newer ones are different but could work, check the sticky thread above on swapping engines. The G1 is very different it has that huge exhaust it needs, I would not go there better to fix the G1 cart and keep it whole. G1 has no reverse if you put a 4 stroke in it.

[G1-G9]

I do have a side cover if that is all you need to change.

[crowsnest]

Thanks for you're quick replies. I wish I could afford to go the Clone route..Unfortunately it's a little too close to Christmas for me to spend the extra cash. I haven't been able to find the fiche to point out the gear but it may very well indeed be what you referred to as the "balancer". Any con's to running it without?..Here's a thought.. Wondering if i could clean out the hole where the end of the "balancer" sets with a dremel to remove the grooves. Then use a cut piece of flat feeler gauge with the right thickness as a shim for the shaft end that goes in the case?.. Sound reasonable possibly?.. Another thing is the play in the rod..moves about an 8th of an inch or so in either direction..Hope that makes since... Were looking to get a few good years out of this thing before eventually going to a newer machine and rebuilding the old completely..Any more thoughts would be greatly appreciated..Thanks again..

[crowsnest]

Also..thanks for the offer on the side cover...Definately something I will keep in mind...:)

[G1-G9]

I ran two of my engines with out the counter balance with no problems.