1987 ezgo marathon clutch problem?

[sharse36]

I have a 1987 ezgo marathon lifted with 22" tires. I have rebuild the top end, new reed vale gaskets, cleaned the carb(its spotless), a new belt, and removed the oil injection(sealed the injection hole). The cart starts right up and runs good a lot of power at slow speed(have pulled a 17' power boat).
Here is the problem the faster you go is boogs down and feals like it has no power but it does build speed(21mph on gps). Then when you slow down and get back on the gas it boogs down and takes a log time to build up power again. Took it for a 4 mile ride tonight and on a hills it lost all speed and when I stoped and started again had the low end power like it has and then flatten out again.
I put it on jacks and it looks like the clutchs are working fine. Also checked the crank seals with carb clean the motor stayed the same sound.
Does any one have any ideas for me to fix this problem? I was thinking the carb but it seams it might be the clutchs

[Dave Box]

There could be lots of reasons, here is just one, but it is a nice easy and free test. The muffler on any two stroke will eventually get jammed with carbon deposits from burning oil. Back in the far off days of my youth my old Yamaha 350 used to have removable baffles so you could clean it out. I would recommend that you undo the two bolts that hold the muffler to the exhaust pipe (don't lose the gasket). Now with a gap between the junction take the cart for a run. If it feels like it is breathing again you have a clogger muffler. If not I have wasted 30 minutes of your day.

[sharse36]

I have had the muffler off and can blow air throw it. I did put it on my turkey roster for 1 1/2hr to try to burn any thing out of it. I did ran it with the muffler off it ran ok but did not go far very loud neighbors did not like it.

[Dave Box]

So it looks like you can rule out a partialy blocked muffler. Another issue, and this is guess, is those larger tires. Effectively you are overgearing it by running 22's. If you are getting 21mph on the flat then that is pretty good. If it is struggling up hills and slow to accelerate this all points to the same thing. A good test would be to put on a shorter belt but now you are into spending $30+ on an experiment. Has the cart always acted like this with these wheels on or is this a new thing?

[sharse36]

It has acted like this as as long as I have had it. I got it this this summer. I was taking to a guy and said his was doing the same thing. He said that the head was worped and losing compstion at high speed. Does that sound right?

[Pocono Country Boy]

I tend to agree with Dave's line of reasoning here... It sounds to me like you are just overgeared with those larger tires.

Spending $30-$40 for a belt that's 1/2 to 1 inch shorter than what's on there now would probably cure what ails ya.

See if you can read any numbers on the belt now to verify what's on it and we can help you find an applicable replacement for it. The OEM should be 45" x 1.118 EZ-GO part number 14153-G1 I believe.

Probably the Dayton HP3004 which measures 44.125 x 1.118 would be the hot setup. It should measure out to be 3/4 inch shorter than a stock belt for an '87 which should give you more torque but not cost you too much on the top end. Any local auto parts store should be able to get you that belt if they don't have it in stock. Advance Auto seems to stock many of them.

[Dave Box]

Losing compression at high speed does not really make much sense and in any case you cannot prove it as compression testing is done at cranking speed. With a top speed of 21mph there can't be much wrong with your engine. As a full disclosure I have the same engine and tires as you and I am happy with everything apart from acceleration and hill climbing ability. When my current stock belt, which is almost new, shows sign of wear I shall be fitting the belt as detailed by Pocono County Boy.
Perhaps another EZGO gashead can offer an alternative solution.
All the best
Dave Box

[Dave Box]

Losing compression at high speed does not really make much sense and in any case you cannot prove it as compression testing is done at cranking speed. With a top speed of 21mph there can't be much wrong with your engine. As a full disclosure I have the same engine and tires as you and I am happy with everything apart from acceleration and hill climbing ability. When my current stock belt, which is almost new, shows sign of wear I shall be fitting the belt as detailed by Pocono County Boy.
Perhaps another EZGO gashead can offer an alternative solution.
All the best
Dave Box

[sharse36]

TRYED to get the drive clutch cover off to clean and look at it but could not get the main bolt out. Is thier a trick to getting the bolt out? Thanks

[GoTeeMan]

You will need an impact to get that bolt out and then you will need the appropriate puller to remove the clutch from the crankshaft.