My first recommendation is to purchase a
service manual from one of our fine sponsors. The manual contains specs, procedures, drawings of pretty much everything you need to know to work on your G1. All of the info you need on the following problems can be solved with the info in the manual. Read through the entire manual and you'll learn a ton!
Common Problems
Since most of the G1's are high use carts and very old, your typical issues come up...
tune up issues, spark plug, air filter, fuel filter, carb cleaning, clutch maintenance, belts, old gas, oil mix, dead battery, etc.
Compression needs to be in the 100psi range to run good, and a fresh rebuild should have around 120-130psi. If you happen to have a 1982 model, sorry but your engine is a lower compression unit and will be around 90-100psi. The 1982 model was Yamaha's attempt to calm down emission and noise, but they scrapped that idea when they realized how much performance was lost and for 1983 went right back to normal. Lower compression is most commonly caused by worn piston rings or oil seals.
Frame rust is always an issue, particularly in the battery tray area. Alot of people over the years cut the old tray out and don't replace it. There are a number of ways to replace the tray, but a custom fab job is likely what needs done. Some new metal angle, sheet metal, a new hold down, some cutting and welding and paint will be in the project. Some other areas are the cross tubes and swing arms because they see the most action and dirt/grime and get washed off the least. Again custom fab to repair.
Oil Injector failure is something that comes up, although I've never seen one fail, I have heard reports of that happening. If this happens it will likely cause engine damage.
Oil seals for the crankshaft are common wear points. If you have trouble starting your cart or it runs poorly, the oil seals are one of the common causes. Worn seals will cause lower compression and poor performance. Look behind the primary clutch and see if there is wetness or oil residue on the crankshaft. If so you'll likely need to to replace the seals.
Clutch issues will cause poor power and speed. The primary clutch can accumulate dirt and grease and cause the clutch to not engage properly. Taking the cover off and cleaning all the dirt and gunk out regularly will go a long way to restore performance. Don't forget to lube the shaft with a tiny amount of grease, too much will cause it to fly out into the clutch housing. The secondary clutches often wear through and/or "dish out". This causes the cart to not have a high top speed, or can cause it to have no low end power.
Drive belts will often wear out/down and cause poor shift out and poor power/speed. Replace belts regularly and measure them to make sure they are in spec.
Fuel pumps often fail in these carts. You can rebuild/clean yours so read up on that. New ones can be found for around $40-50. Or you can rig up a fuel pump from a tractor. If you don't have fuel at the carb, look to the pump or fuel filter.
Old gas is really a basic that people often forget. The gas in the tank from a cart that has been sitting is likely not any good. And likewise the gas in your gas can from last fall may not be that good either. If you can't get your cart running, buy some fresh gas and try a new plug. Don't forget to fill the oil reservoir!
More to come.....