The engine needed some work, it was sluggish and I felt it could be better. I replaced the ignition coil, spark plug, crankcase breather, adjusted the valves, installed a new battery, new fuel filter, and changed the gear oil. The gear oil probably hadnt been changed in decades; it looked like grey mud. Gear oil is very heavy weight and is a golden color like cooking oil when its clean.
Next I decided to replace the secondary clutch spring with the performance spring which had higher tension and was supposed to add more torque. I didnt notice it, but I did notice a reduction in top end speed.
The new spring is in the center. Pain the ass to replace.
I also replaced the carburetor, removed the governor so the cart could go faster, replaced the throttle cable, and fuel line. While doing this, the fuel filter came apart so I ordered a new one, which was a piece of shit and fell apart right away. I sent it back for a replacement and this time ordered something legitimate from UNI.
The stock configuration didn't vent the crankcase blow-by emissions to the atmosphere; that violates EPA emissions laws. But a lot of people do it to older vehicles for reasons such as introducing cleaner intake systems. When I first installed a crankcase breather, I didnt use a PCV valve, but vented straight to the atmosphere. This time I installed a universal PCV valve and vented the crankcase emissions out to the back of the cart with a long emissions tube and a K&N breather filter.
Here's a photo of the new pod filter on the carburetor.
New fuel line, I didnt like it and replaced it with some different fuel line.
After this work, I convinced my buddy Brad who lives down the street to take a ride with me. I took it out a few miles down the road and onto Admiral way, which is a busy arterial behind my house on a steep hill. When we took it out, it was also rush hour in the evening. Top speed we got it up to was 35mph, which I think damaged the motor. I had removed the governor so it was able to go faster, and I think this over-revved the motor and caused damage .
I took the cart out again soon after and it kept backfiring, so I did some research. I thought the issue was an issue with the carburetor throttle linkage, which was causing the throttle plate to remain open when decelerating. If this was the case, fuel would continue to be introduced to the exhaust chamber which was already hot and creat a secondary combustion, or backfire. One other problem I was having was backfiring through the carburetor.
I adjusted the carburetor again, replaced the throttle cable, and replaced the 38mm go kart exhaust with a Yamaha R3 sport bike exhaust.
Here's the go-kart exhaust, its tiny
The original exhaust I fabricated was sloppy, so I worked on creating a new one
I also wrapped it in black heat wrap to protect the cart's body from excessive heat
The finished exhaust, done without any welding. Looked and worked pretty good
The cart kept backfiring, so I decided to replace the pulse fuel pump. That too didnt fix the problem.
Replacing the fuel pump didnt fix the problem so I decided to adjust the valve clearances. Bought some feeler gauges online and checked the clearances. They weren't too far off really.
Adjusting the valves didnt fix the backfiring, and the problem got worse. I took it out for a test drive and the cart wouldn't maintain speed and kept backfiring. It also ran hot, very hot. This sounds like a lean condition but it wasnt. I took it home and tested everything including compression but everything seemed normal. At this point I was out of options so I reached out to that cat in Leavenworth I sold my vintage Honda CB500 to. We discussed options, and I decided to pull the motor and take it to him. Check out this video of the engine problems:
Cal measured the cylinder walls and it was "out of round", meaning the cylinder was no longer symmetrical. This is usually caused from age, or could be from bad timing, overheating, or other causes. My original thought on the cart losing power was loss of compression, but Cal tested the combustion chamber compression and it was fine. We looked it over and thought it was best to replace the motor. The stock motor was 27 years old, had never been rebuilt, and was worn out.
Checking the combustion chamber; pictured here is the cylinder.
Intake and exhaust valves.
Thanks for the memories
Of course my mistake at this point was telling my pops I figured it was caused by me driving too fast, and I never heard the end of it from him. He hated the way I drove the cart; he was adamant that I was reckless in it and drove too fast. He's old, so everything is too fast. If he had a front lawn, he would be yelling at people to get off of it.
I considered several options; rebuilding the motor, replacing the motor with a Harbor Freight Predator 420cc motor with a conversion kit from vegascarts, or a big bore motor kit from Vegas. I went with the conversion kit since it was supposed to be the most economical with a new motor.
I bought the motor from Harbor Freight; it was a 13 horsepower motor and cost about $300. The stock motor was 285cc and 8 horsepower, so a big gain. The conversion kit from Vegas was a new engine mount; primary clutch, belts, exhaust header, muffler, and other accessories; it was $749.
Well, we ran into a problem with installation; Harbor Freight had modified the motor slightly and it did not fit correctly. The kit was specifically designed for this motor; it was a popular option by other enthusiasts. I called up Vegas spoke to Geoff, the owner. He said they did not build it so could not guarantee fit. Sucked, but such is life.
Some days I feel like Sissyfus; because I only have a small list of items that need to be completed on this golf cart, but they never get done or something always comes up. No matter how hard I try, it never gets done. For the last year or two, the cart hasn't ran. It quit running when the pilot jet got clogged, then I decided to swap the carburetor out for a Mikuni style flat-slide carburetor with a pancake style reusable filter for a number of reasons. I also decided to remove the stock gas tank and swap it with a spun aluminum external tank, install a new header and muffler, repaired the cylinder head since the exhaust flange cracked, got the wheels balanced by Les Schwab since they wobbled, installed an electric cooling fan in the rear, and repainted it again.
After my parents bailed again to their winter home in Tucson for the winter of 2016-2017, I towed the cart back from Bellingham to Seattle for some tear down and rebuild work. When I do projects, I rarely work from formal plans. I loath structured work like that and prefer to do it as I go with an informal plan in my head. I had decided what I wanted to do was replace the front suspension, resolve the steering shakiness, replace the secondary (rear axle) clutch spring with a higher tension spring which delivered more torque, upgraded exhaust system, improved electrical system, higher wattage headlight bulbs, connect the horn, and some additional engine work. I started with the front suspension by ordering some 11 inch coil over springs that I bought on eBay I think. They were basically motorcycle shocks and much more rigid than the original 30 year old ones. They also looked cool. The first problem I discovered was the metal sleeve inside the bushing of each shock was too smal
The old carpet was in bad shape and was moldy, so I went to the Home Depot and bought new utility carpet and cut it out to fit using the old carpet as a template. It looked and worked great! Before, original carpet After, new carpet I also replaced the gas pedal because the old one broke while replacing the throttle cable. Oh, I also replaced the windscreen cause the old one had fallen apart. The windscreen could fold down in the middle and was held together with a rubber seam in the middle, but that had deteriorated. I also installed a new rear view mirror on the top of the windscreen and a cool Ducati logo. Cal finished the motor installation. As mentioned, the motor retrofit took 40 hours, much more than the original 4 hours quoted. Cal builds bikes for a living; hes legitimate and I believed him. It was a lot of money, but oh well. I drove up to Leavenworth to pick up a trailer and pick up the cart. We took it out for a test ride and man was it fast, and LOUD. I was g
The stock configuration didn't vent the crankcase blow-by emissions to the atmosphere; that violates EPA emissions laws. But a lot of people do it to older vehicles for reasons such as introducing cleaner intake systems. When I first installed a crankcase breather, I didnt use a PCV valve, but vented straight to the atmosphere. This time I installed a universal PCV valve and vented the crankcase emissions out to the back of the cart with a long emissions tube and a K&N breather filter.
Comments
Post a Comment