View Single Post
Old 08-02-2010, 11:57 AM   #28
sho305
Vegas modded 420
 
sho305's Avatar
Yamaha
 
Join Date: Jun 2009
Location: West MI
Posts: 15,433
Default Re: The CLONE engine setup & specs thread

Where is everybody? Anyway, so I plan to look up a few things. It appears they put a blank threaded stud into the idle mix on the side of the flange and locktited it. Maybe I can figure out how to put a slot in it but likely you have to heat it to get it out anyway, some say soak it with penetrating oil. It needs to be richer to stop the popping on slowdown. If you search youtube for clone carburetor one of the parts places Stout has a nice video of one, think its the 6.5hp but it is near the same. He tears it down and talks about the e tubes and so on. Since these are EPA carbs you can't adjust much. The idle you pop the cover off and can turn it. I will look into the adjustable jet kits for them that would be ideal to tune it in. Lots of stuff available for big block gokarts using them or using the parts from them, they put this carb on built 6.5hp engines.

Also want to investigate what timing it should be at and how to check it. You can cut the key down and advance it, not even buy an offset one but they are pretty cheap. I think it would pull harder on top. I'd guess I had it at or above top speed with my stock cart, we were on dirt so that would be 28mph gps, and I let off plus it would plug the fuel pump soon after. Will try to remember to have my gps next time. On top of all that, that is with 15psi in my rear tires and all his tires were soft and we had two people in it. The lean idle circuit might also be cutting power on takeoff before it revs some, for all I know it still needs to be richer on the main since it needs to run a minute before it will take wot. What did you guys do with your jetting or did you run an airbox that cut the flow?

That leads me to speculate that while the float bowl is easy to get at this way, I would really like to make an intake to move the carb elsewhere. I'll try to get some pics loaded here.

Wonderful hand made throttle and choke linkages from yours truly that need some paint. One uses the original governor arm, the other is just 1/8x1/2 steel and some rod we had. And look three ways to start it up!


Note the very tight fit aribox to rear shock, you better chop a lot of crank off or change the carb mounting on a Yami or it aint going to fit! Or, I see some bought mounts use a longer belt but we did not it is aligned same as stock. I did the intake and he did the exhaust, might change exhaust anyway. IIRC he used the stock yami flange on the exhaust to head. We had some conduit to use that would have fit, but remember the engine is in rubber mounts. BTW it does seem pretty smooth really, I didn't feel any vibrations through the cart more than stock really...maybe a hair around idle speeds but not much.


Bottoms up, note the oil drain right there. Heck this was the easy part.


Sweet GM airbox worked out great, we did have to cut the elbows shorter to get it low enough to clear the seat. Replacement filters should be cheap if they ever get dirty. The pipe comes out between the top bolts of the front shocks, actually where stock ones would be since there are lift brackets lowering the shocks there. Its right behind the 'yamaha' badge on the front. He spraycanned the pvc I will not bother on mine, is kind of ugly in white however. Note the airbox is mounted to the frame not engine cradle, so the huge car hose takes up the movement and the pvc is mounted under cart with a exhaust clamp welded to the frame near the gas pedal. That top tube behind the seat will crush the big hose a little when I jump on the rear bumper but its so big should not matter....and that is why the hose goes just under the tube to above the carb. There is a mount here to hold the pvc on the carb box that box is not that HD, but stronger with the plate inside it sealing it up.


Now I have to get one of these in my cart! My inlaw will be blowing by me every chance he gets until then.
sho305 is offline   Reply With Quote