GY6 Reverse Gear Box

[kittletstv]

Anyone have any info on using the reverse gear box off a GY6 150 on 14 1/2hp Subaru or similar engine in a buggie project? Or possibly cutting off the transmission section of the GY6 and adapting it along with the reverse gear box to a different engine? One of my project buggies is a Manco XTK 713E with a strong 14 1/2 Subaru engine but it doesn't have reverse so I'm curious if anyone has tried this type of combo?

[x-bird]

ok, 4th time, every time i go to post, i lose this ...

I've heard people talk about doing what you propose, but have yet to see anyone do it.

It is feasible. Initially i was going to suggest drive chain to jackshaft with a reverse box mounted on it, but you won't have a "neutral" to allow shifting between F & R.

So, GY6 clutch, variator, reverse box and output shaft. you need to have the room behind the engine to put the variator on the engine's shaft and run the belt the same distance as a gy6. on the left would be a side frame mount with a support bearing for the shaft. on the right would be a frame mount to bolt the gearbox's right side half to.

axle sprocket would need to be relocated.

another way to go would be to get a centrifugal clutch on the engine and a sprocket on the left side of the gy6 shaft where the clutch normally goes with the rest of the build the same---this version would take away the need to replicate variator/clutch spacing for the belt.

with a 14.5 suby, i'd get parts (variator/clutch) from a cn/cf 250.

[kittletstv]

Thanks x-bird for your imput. I just got back home from the Holiday weekend. Still having issues with this GY6 150 so the frankenstein build is looking more & more interesting to possibly try. At least it would be an engine combo that I could get parts for a whole lot easier. Thanks again

[kittletstv]

Would you have any suggestions as far as the GY6 150 goes? It was already giving me some trouble of not running smoothly, but it was speratic. Then I recently added a new Uni air filter & velocity stack to give it a little pep or so I thought. The original main jet was a 107. They sent me a 125 & a 130 with the new combo. Since we were going from an elevation 0f approx 1,700 ft to a little over 6,200 ft above sea level I started with the stock main jet. It ran fine here in the desert for about 10 -15 mins then it sputtered a few times and quit. I could barely get it started and up onto the trailer. Once in the mountains it would not run worth beans so I changed the 107 main jet out to the 125. I had to crank and crank it over to barekly start and it didn't run any better or worse than before. Still sputtering & not coming up to speed, stalling every time I let off the gas. I then changed over to the 130 main jet. The same issues with no changes. I pulled the carb off & tore it down bare, cleaned it out, and reassembled with the original K34 pilot jet & the new 130 main jet. Had to crank it a while but once it started it ran fine for about 20 -30 mins other than loading up just a little 1 time. I floored it and let it clear itself out and it was fine for another 30 -40 mins. We shut it down for about 10 mins, then it would never start & run right again. After numerous attempts to start it, if it did start even with it floored it would only sputter & bobble along. If I tried to feather it out to find a smooth spot, it would die every time. Then finally it just wouldn't start at all irregardless of what main jet I used, or mixture adjustment was made. Any suggestions or is this what is to be expected from these engines? Also where can I find a carb kit for these things? Everyone I 've talked to tells me that there isn't any such part/s avaliable.

[x-bird]

if you haven't already, check the valve adjustments. if you're jumping up 5,000 feet in elevation, you want smaller jets. also, the gy6's are rather "finicky" regarding intake tract length. how long/what configuration is the "velocity stack" you added?

Once dialed in, it should be a trouble-free engine. i could probably go throw a battery and fuel feed on the one i have out in the yard under a tarp for 6 months+ now and get it to fire off and run.

biggest issue is usually keeping the carb clean with ethanol-added fuel. best habit to develop is to shut the fuel supply off after every ride and run the carb out before shutting down. My wife's baja gives me fits since it's rarely ridden and the gas sits a long time. if i forget to clear it as above, I just throw a spare carb on it and clean the "bad" one later for the next time--done that about 4 times now.

[kittletstv]

X-bird, Thanks for your imput. The velocity stack came with the 2" UNI air filter as a combo kit with the 125 & 130 main jets included from BUGGY PARTS NW. It's a tappered 4" stack, to go from 2" for the filter then tappered down to match the 1 1/2" throat of the carb. I also added a 3 1/2" section (between carb & stack) of a 1 1/2" Radiator hose that had a small bend in it to help tuck under between the upper cross member in the engine frame and the starter. It is approx. 13" from the end of the radiator haose on the carb intake port to the end of the UNI filter. It worked very well to also offset the filter to the right side a llitle to help keep the chain lube reisdue off the filter better. Do you think this set up is too long? The combo kit came with a 2" short piece of rubber tubing to join the stack to the carb. The strangest part of all of this is that I had trouble with the original carb so I bought a new one for it. Inially it worked good. I started it every few days or so checing it out since we had just recently bought it used. Then it started acting up by being hard to start, if it did start it would sputter, run rough and die time after time. This was way before the filter / stack & main jet change/s.

[Masteryota]

Originally Posted by kittletstv

X-bird, Thanks for your imput. The velocity stack came with the 2" UNI air filter as a combo kit with the 125 & 130 main jets included from BUGGY PARTS NW. It's a tappered 4" stack, to go from 2" for the filter then tappered down to match the 1 1/2" throat of the carb. I also added a 3 1/2" section (between carb & stack) of a 1 1/2" Radiator hose that had a small bend in it to help tuck under between the upper cross member in the engine frame and the starter. It is approx. 13" from the end of the radiator haose on the carb intake port to the end of the UNI filter. It worked very well to also offset the filter to the right side a llitle to help keep the chain lube reisdue off the filter better. Do you think this set up is too long? The combo kit came with a 2" short piece of rubber tubing to join the stack to the carb. The strangest part of all of this is that I had trouble with the original carb so I bought a new one for it. Inially it worked good. I started it every few days or so checing it out since we had just recently bought it used. Then it started acting up by being hard to start, if it did start it would sputter, run rough and die time after time. This was way before the filter / stack & main jet change/s.

I am sure someone else will chime in soon, but I think the recommended length for the 'velocity stack' is no more than 6 inches. After that, the air loses speed and begins to tumble, which does not work well with the venturi that picks up the fuel in the carb. Shorten the stack back the what was sent with the filter kit and see if makes a difference.