87 EZ Go Marathon Time for rebuild?

[YourCustomCart]

I purchased an 87 EzGo Marathon a couple of weeks ago with plans for a complete rebuild and some customizing to get around at car shows. To my surprise, I got it to run today after a thorough carb cleaning, a new battery, and fuel lines. I noticed that it has a Robins engine, although I am unsure of the size. I did as compression test on it after I found how little power this thing has. So far my top speed is about 6 miles an hour going downhill!

The compression test showed a whopping 70 psi. I'm not positive on what kind of number that I should see on a compression test with this kind of engine, but I imagine it should be at least 110psi. Its certainly different than the 350's I normally build!

I have seen many websites that offer rebuild kits and they seem to be affordable. I am hoping that a "top end kit" will be sufficient, but I am curious to know how to check the bottom end components to see if they are ok to continue using. What do I check for? Any suggestions?

[BrewCityMusic]

Welcome to the forum - here are some pointers for you:

The engine in your cart is a 2-stroke Robin 2PG, which is actually a pretty strong little motor. Your compression, however, is really poor - the 2PG should be at a minimum of 130psi in both forward and reverse (if you haven't noticed yet, that drivetrain actually runs the engine backwards to give the cart reverse gear!). As to the rebuild, doing the top end is a piece of cake and if you're not too easily frustrated can be done right in the cart.

As to the lower end, if you aren't hearing any rattles, etc, a rebuild shouldn't be neccessary as long as you do a basic inspection for play in the crank, etc and it goes OK. You'll want to check the crank seals though, as the best time to replace them is with the motor out and what's nice is they can be done without having to split the motor. Jack your cart up (so it doesn't run away from you) and run it at just above idle. Have a friend spray a little carb cleaner or WD40 into the fan at the front of the engine, then at the rear of the engine where the crank emerges - if your RPM's increase, better go ahead and do the seals as they're allowing air to leak into the crankcase (which WILL stop you from running sooner than later).

Finally (just a tip) - if the oil injector hasn't been removed yet, you may want to consider pulling it and running 128:1 premix. As the oilers age, they tend to get a little less than reliable and many a good engine has gone bad because of them.

If you have the ability to have your cylinder bored, etc then a piston and ring kit should do it - sometimes obviously just the rings go bad and people get lucky, more often than not though the cylinder is probably scored up pretty well in which case the top end "Kits" for around $200 are an easy install and probably your best bet, grab a six-pack and an afternoon, badda-bing you're back in business!

(There's a good video floating around the forums on rebuilding the 2PG, a simple search should find it for you otherwise hopefully someone else will post the link for you)

[Dave Box]

I agree with everything BrewCity said. I have just rebuilt my 86 and it is running like a sewing machine. The only recommendation I would make is to replace the crankshaft seals no matter how good they look. It is going to cost you an extra $6. As BCM states you can get a piston set and rebore your cylinder, you can also buy a top end overhaul kit which gets you the cylinder, piston, rings, wrist pin and bearing as well as the gaskets. This will set you back ~ $200.

If you go to youtube and search for donyboy73 you can find a good video on rebuilding the 2PG engine. At the end of episode 2 he makes the classic error of replacing the piston backwards, he corrects this in episode 3 but you can bet he finished the rebuild and spent days trying to make it run. The moral is make sure the port faces the carburetor

[rib33024]

Here it is-

And here's a link with pics

http://www.buggiesgonewild.com/manua...ND_REBUILD.pdf

YouTube - Gasoline Golf Cart ENGINE REBUILD Part 1/3

YouTube - Gasoline Golf Cart ENGINE REBUILD Part 1/3

[bananaman]

Is everyone still running their governors also or are they disconnected?

[Dave Box]

There are (of course) two opinions. I restored a cart that had been abandoned in the woods and bought the governor cable fully intending to make it work. Subsequently not only did I not install it but I also removed the actuating lever by the clutch. My reason for not installing it is that only my wife and I drive it and we are both sensible mature drivers. In addition I installed a cheapy rev counter and I make sure that I never take it above 4000 rpm.

Now if I had small children, relatives, drunken buddies who I thought would abuse the cart that I invested $2k as well as countless hours of blood, sweat and tears you can bet your stones that not only would that governor be back on but it would be set to 10 mph.

Dave

[BrewCityMusic]

Well put, Dave - I have a few buddies who occasionally drive my cart, add in the fact that I live at an old Ski Resort full of hills and the fact that usually the cart comes out after a few beers and it was a no-brainer for me to redo the governor, just to protect said investment(s).

For the record, if you set the governor correctly, you'll really only lose 2-3mph on the top end (although mine is set so it flirts with redline on occasion) and no effect on power or accelleration - just in case that possibility was scaring you