Yam. SRV 540 swap into Columbia
 

Figured I'd throw a couple pics up of my junk. Been an after work project for a little while.

The crank bearings got loose enough in the OE motor that it took out the ignition module during some extended late night snow donuts/drifting. I totaled up what it would cost to fix vs. swap in something else and it was a no brainer. Enter the $100 '85 Yamaha SRV with a 540 fanner. 56 HP vs. the OEM 7 HP.
here we go....
Stock
http://i94.photobucket.com/albums/l9...1206122156.jpg
http://i94.photobucket.com/albums/l9...1207122120.jpg
Last time the old motor sat in here.
http://i94.photobucket.com/albums/l9...206122156a.jpg
Cut off the old drive side motor mount and aligned and welded some 3" channel to the bushing bracket
http://i94.photobucket.com/albums/l9...1219122107.jpg
Fabbed up a couple of new motor mounts and shot em with some "safety blue".
http://i94.photobucket.com/albums/l9...1219122108.jpg
http://i94.photobucket.com/albums/l9...219122108a.jpg
http://i94.photobucket.com/albums/l9...1219122118.jpg
http://i94.photobucket.com/albums/l9...1219122210.jpg
Going to have to lift the body about 2" to clear the new engine.
http://i94.photobucket.com/albums/l9...1219122213.jpg

I'm using the OEM passenger side motor mount rubber and yamaha mounts on the other side. I think I may have to switch to the yamaha mounts on the passenger side as well as the OE mounts are really soft and I think they might deflect when the clutch starts pulling.

I'm going to try using the stock golf cart driven clutch and a comet 102c drive clutch off the yamaha with the stock golf cart belt. So far it's all pretty close. The hardest part of getting to this point is aligning everything. It's tough to find good places to measure to and to find square since everything is on an angle or round.


Next step is to make the pipe fit, no small task. Then the easy stuff, CDI and carb.
After the first test drive I'm going to tear it back out and mount the original starter/generator so I can get back the pedal start feature and have reverse.

Re: Yam. SRV 540 swap into Columbia
 

Doesn't look like anyone cares, but I'll put this up anyhow. Video of test firing the engine and running the clutches up to speed with the rear end on jack stands.

A plug wire fell off as soon as I started it so it's only firing on one cylinder.

Re: Yam. SRV 540 swap into Columbia
 

Got the exhaust, throttle cable, and wiring all rigged up, still have some things to button up, but I took it for a test drive tonight and so far so good.

http://i94.photobucket.com/albums/l9...psb1a1371a.jpg
http://i94.photobucket.com/albums/l9...ps61094dc1.jpg

Re: Yam. SRV 540 swap into Columbia
 

For those with the youtubes. A little boring but it's proof it moves.

Re: Yam. SRV 540 swap into Columbia
 

Does anyone know what the top speed of the stock starter/generator is? I'd like to hook it up but I got to wondering what will happen to it when I ask it to spin twice as fast as stock.

Re: Yam. SRV 540 swap into Columbia
 

Well, nobody said anything so I went ahead and hung the starter generator on the 540 to try it. I used a second crank side fan belt pulley and made up a spacer for it and stacked them. Smaller diameter than the stock golf cart engine's pulley. Will lower the starter/gen speed by almost half relative to the motor so it should be almost back to it's stock operating speed range. If need be, I can make up a smaller pulley for the starter/gen.
I haven't seen many pics of mounting a starter generator to a sled motor so I thought I'd put a couple up for others to get ideas from.
I still have to space the pull start housing off of the engine so that I'll have that for backup.

http://i94.photobucket.com/albums/l9...ps48f6f86b.jpg
http://i94.photobucket.com/albums/l9...pscd06a2b8.jpg
http://i94.photobucket.com/albums/l9...ps96b3642e.jpg

Welded a tab onto the motor mount for the rear starter/gen mount then used a longer bolt and spacer into one of the existing fan shroud holes. Made a plate that bolts on the starter/gen to relocate the tensioner hole too.
http://i94.photobucket.com/albums/l9...psbe730766.jpg
http://i94.photobucket.com/albums/l9...ps291910fd.jpg
http://i94.photobucket.com/albums/l9...psc0963916.jpg

Took some time out of the weekend, but what else are you going to do when there's 6 feet of snow outside and you're getting board with the normal winter activities?

Next step is to pull off the flywheel and see how to make it run in reverse. I'm thinking of using a couple relay's that would switch the polarity of the pickup coil. We'll see, never been under there before.

The carb is also acting a little weird now that it has a free flow airfilter on it instead of a chunk of t-shirt. Has a lean spot at part throttle. I'm pretty sure it's because it's on such a steep angle. I'll see if I can address that tonight.

Re: Yam. SRV 540 swap into Columbia
 

Well, got a little too squirrely with it last night during a test drive. When I let off the throttle during a power slide down the street, the golf cart secondary backshifted so hard that the rear tires couldn't regain traction at the speed I was going and we got too far sideways and rolled it. My hip and upper leg are beat up, arm is dented. The wife was on the high side and got thrown a ways. Broke her helmet, scraped her knee open through jeans and bruised her up a little.

Need to figure out a way to keep that secondary from backshifting so readily during decelleration. I think it might have to do with the double helix to be able to work in reverse.

Also, the carb still lean bogs during tip-in even running level. Once you get to WOT it's okay. I'm going to clean it before I start changing jet's out.

Re: Yam. SRV 540 swap into Columbia
 

Sorry you wrecked it,hope everyone is OK.I had a sled engine in mine,could never get it right.
Don't think no body is looking at your build,good job.8)hookm

Re: Yam. SRV 540 swap into Columbia
 

Thanks, I didn't think anyone was following! The cart is fine aside from a scratched up rear bumper. It landed on it's side in a snow bank (the snow banks are about 6 feet tall on the side of the roads here) so the fiberglass was spared.

Re: Yam. SRV 540 swap into Columbia
 

Got the relay hooked up and drove it around the garage tonight, automatically starts and stops the engine with the pedal and starts/runs in either reverse or forward at just the turn of the key! Now that it operates just like it used to when it was a golf cart but with a more effective throttle pedal, I'd say it's development stage is complete. Now comes some of the smaller details:
1) quieter airbox
2) front brakes/atv front suspension
3) clutch tuning
4) carb tuning
5) radio
6) more effective set of tahrs
7) roll cage/5-point