New to me 84 Marathon ????

[sandman1]

I was recently given an 84 gas marathon by a friend of mine because he got a new cart and was tired of changing spark plugs. I figured out he's been mixing his gas way too rich and fouling plugs. Now it runs better but what doesn't make any since to me is why it runs better in reverse than foward Has anyone done a motor swap with one of these with the sideways mounted engine? What engine did you use? I have a 244cc engine and would like to make it an off road machine but need more power. Is my best option to change to a newer rearend? If so where can I find one? I know it's alot of questions, sorry. The cart is in pretty good shape as far as the chassis an body. Any help would be very appreciated.

[ScooterMcTavish]

Running better in R vs. F can be many things, but initially suggests that the crank seals may be shot. Unfortunately, they wear unevenly, and since carts go forward more than in reverse....well you get the picture. And these carts need the crankcase pressure to drive the fuel pump.

A quick test is with the drive belt off (or on jack stands) try running the cart in F. While running, spray some WD-40 at the seal between the clutch and the block, and behind the fan (as best you can). If the revs pick up, it's likely crank seals.

While you're at it, a compression test is also good, as if you want a cart for offroading with power, you'd like to have an engine that is performing well. If the compression test tells you are close to needing a new top end, and you already have to take the engine out for crank seals, then why not get both things done at the same time.

[sandman1]

Hey thanks, that helps alot. I'll check that this weekend. Yeah if I have to pull the engine I will deffinatly go ahead and put a new top end on it.