Gas 2 Cycle EZGO Marathon Won't Start

[mnvrice]

I have a real head scratcher. Bought a 1982 EZGO Marathon 2 cycle that turned over but won't start. I removed the oil injection, put in fresh fuel mixed 128:1 in the tank, replaced the carb, fuel filter, fuel lines. I got a new plug and have good spark. Did compression test and got 100psi at the plug. What am I missing??? Engine won't start or even fire

[BrewCityMusic]

Crank seals. If one or both are bad You can have all the compression in the world but the engine will not develop enough internal vacum to pull the fuel into the cylinder. Jack up the cart (for safety) and turn it over while spraying some WD40 in the front fan, then try it again at the rear of the engine where the shaft exits the block - if either result in a popping or even starting, you need to replace the crank seals.

[mnvrice]

Thanks for the advice, I will give it a try. How hard is it to replace the crank seals?

[BrewCityMusic]

It can be a straightforward, roughly hour-long job if it all goes smooth, or it can be a BEAR for days if the flywheel is frozen in place, etc ... You'll need a Clutch-removal tool specific to EZGO (or you could fab one up yourself with basic welding and cutting skills), You'll also need a Flywheel Puller (a heavy Steering Wheel or Gear Puller will do in a pinch) .... The seals are cheap, roughly $5 each, so it's actually not an EXPENSIVE proposition.

The basic procedure is to remove the belts, remove the clutch, pry the bad seal carefully out of the crankcase and off the crankshaft, lightly lube the shaft, slide new seal into place and tap firmly to seat, replace Clutch, belts, etc - THEN remove the front engine cover, ground straps, etc (generally easier to pull all starter wiring, etc to keep it out of the way prior to starting this part). Once into the front of the engine, remove fan and retaining washers, then use Flywheel Puller to remove flywheel. Pry seal out and off, then reverse the procediure and reassembly ... Again, if You've done it before and have the tools it can be an easy hour or so job provided the flywheel isn't corroded or frozen in place, if thats the case it can take a day or two of soaking with penetrating lubricant (PB Bl;aster, etc) to help get the flywheel off safely and without damage.

[thekidd76]

Resurrecting this thread. I tried this technique and it tried to start while spraying the rear seal, so I assume it's bad. Two questions, is it easier to pull the engine or replace while installed, and second, of I'm replacing the rear should I do the front as well while I'm at it?

[restore49]

Pull motor - good time to clean up - absolutely replace both seals.