86 G1 complete rebuild, frame off

[daveswaves]

Originally Posted by sho305

Most sleds don't move until you hit 3K rpm likely why they don't have reeds. I have a 440 I could use in a cart just not sure I'd want to build one.

I hear you, low speed circuit is tough. I have a line on a couple of carbs, 2 tillitson and a walbbro that were used on go carts. I like to experiment so we will see what happens. I can always go back to stock and I can play with the primary clutch to increase engagement speed. We'll see.

[sho305]

Could try this one I found, I don't know anything about it or the place. There was also one on ebay.
http://www.dratv.com/allchrome30mm.html

[daveswaves]

Thanks, I will bookmark that. The Keyhin was the original carb but they were touchy, great when new but...

[sho305]

IMO I don't know how anything could be worse than these lawn carbs. It may take some work to get another carb setup right no doubt, but these lawn carbs are just that a dirt cheap thing with minimum capabilities. Even the gokarts usually run WOT so they don't care they just need a main jet. Personally I'd like to have EFI but still difficult to do it. There is a system that uses common GM injectors and such, but it is much more complex than the EFI they use on sleds and some lawn engines. All this technology we have today and you can't do such a simple task.

[daveswaves]

Originally Posted by sho305

IMO I don't know how anything could be worse than these lawn carbs. It may take some work to get another carb setup right no doubt, but these lawn carbs are just that a dirt cheap thing with minimum capabilities. Even the gokarts usually run WOT so they don't care they just need a main jet. Personally I'd like to have EFI but still difficult to do it. There is a system that uses common GM injectors and such, but it is much more complex than the EFI they use on sleds and some lawn engines. All this technology we have today and you can't do such a simple task.

Well, EFI is not out of the question. Here is a pic of a throttle body injection system that I built for my merc inline 6. As you know they were carbs only. I have had it running on my inline but ran into a problem with the efi computer. I had used a polaris snowmobile computer but it had no low end control. The sled kicks in at 3000 rpm as you know so idle down to 500 rpm for the boat was a no go. At 3000 rpm I am doing 30 mph in the boat, kinda fast for the marina lol. I have a new generic computer that I can program but I have lost interest in the project so will put it aside.

[sho305]

Originally Posted by daveswaves

Well, EFI is not out of the question. Here is a pic of a throttle body injection system that I built for my merc inline 6. As you know they were carbs only. I have had it running on my inline but ran into a problem with the efi computer. I had used a polaris snowmobile computer but it had no low end control. The sled kicks in at 3000 rpm as you know so idle down to 500 rpm for the boat was a no go. At 3000 rpm I am doing 30 mph in the boat, kinda fast for the marina lol. I have a new generic computer that I can program but I have lost interest in the project so will put it aside.

Oh that is a very cool project! Yes I would guess you might have to retard the timing at low rpm, though the race guys set it up without and start in gear. I should get mine out this summer and clean the carbs and fire it up, its been about 3yr since I started it. I only ran premium in it since it was the '73 with the high domes.

[daveswaves]

Had a chance to work on the G1 rebuild/big block project. The engine is just waiting for the carb, likely Monday. If you have not been following the engine is a 1979 Yamaha enticer 250 snowmobile engine. I rebuild it into the G1 215 crankcase, when you look at the pics it looks stock, except it is rated at 23 hp at 6300 rpm with the stock pipe.
I did mock ups today, the gas tank is relocated to the passenger side, the battery to the driver side. The snowmobile tuned pipe is shown, kinda like the angle/attitude and the exhaust will exit into the wheel well.

[sho305]

Looking good, did you manage to keep the pipe about the same....it looks pretty close. Can't wait to see how it runs out. I got my head off today maybe get it cut next week.

[daveswaves]

Originally Posted by sho305

Looking good, did you manage to keep the pipe about the same....it looks pretty close. Can't wait to see how it runs out. I got my head off today maybe get it cut next week.

Yeah the pipe is unchanged from the snowmobile. I might re bend the pipe so that I can lay it flat, we will see. Have to do the clearance measurements for the seat assembly and that might force the issue. Still playing. I am going to route the electrics away from the fenders and keep them dryer.

[sho305]

You could wrap that whole pipe if you need to. It should really run with the pipe, though G1 clutch might engage too low rpm may have to adjust that. But you will get full power most people don't do the pipe and lose it.