Engine speed and momentum 86 2 stroke ez.go

[van the man]

Howdy! So, here's my delimma:
I bought an 86 2 stroke. It seemed underpowered some. I checked compression fwd 125 rev 125. Belt was worn and I replaced that. Made a difference, but not where it seems it should be. Removed governor. Removed and cleaned carb. Adjusted throttle cable. Plugged oil feed (the oil reservoir had been bypassed some time before). Muffler looks new. Removed drive clutch cover, has a new comet clutch installed. Driven clutch appears to operate normally; when jacked off the ground, revs to limit, clutches working. Put it on the ground, in forward, it seems clutch tries to engage at slow engine speeds, little power. Can't climb hills. Put it in reverse, the thing Flys right up them, revs high. So it seems somehow in fwd the clutch tries to move the cart at slow engine speed, not fast or powerful enough to really get going. Like it needs some kinda stall until the engine gets higher in the Power band. I worked at a bodyshop that had a 2 stroke cart that would really fly. Spin wheels and such. This one, not so much. Stumped. Carb adjustment? Change spring setting on drive clutch? Something else? It's a mystery... sure runs good without belt or when wheels off the ground. Runs strong, way higher rpm than i would run it. Really screams. Any ideas?

[my1423]

Crank seals are probably shot. Possibly main bearings worn as well. People will rebuild the top end and neglect the bottom. Those seals grab better in reverse due to the swirl lips on them.

Put mic on the crank and make sure you do not have a bearing issue.

[van the man]

Oh, crap. Gonna need more beer.
One this old, prob'ly should overhaul the whole thing if I gotta go that deep, huh.
What's max hp out of these anyway? (Stock). 9 or so? Any gain to be made from different rings/piston? Any hi po cranks and such? I guess they were built to quietly putt around a golf course all day every day for years, not spin tires, etc.

[BrewCityMusic]

No need to really tear it all apart unless the crank moves if You tug up and down on it, the seals are an easy swap other than the flywheels on the old 2-strokes tend to seize up pretty good and can be a bear to get off (best to start spraying everything with PB Blaster ASAP and keep doing it every time You remember until You actually tear into it) ...

I had an 88 that would hit 28mph with a 5" lift and 22" tires, and that was stock - the 1988 was a one-off year though with the "High Output" 2PG engine that put out 11hp, the stock 86-87 puts out approximately 9. The main difference between the 2 is they went with the BV24 carb in 1988 instead of the standard BV18, and the exhaust was totally different and far less restrictive - the easiest way to add some "get-up" to the older 2PG's would be to find or fab a less restrictive exhaust and replace the BV18 with a BV24 - I say "or fab" because being a one-year exhaust, the headpipes for the 88HO is nearly impossible to find, even used, and the mufflers are out there (both NOS and aftermarket) but are pretty expensive.

Here's a fast way to check the seals, jack up the cart and run it at a low, consistent speed, then spray some starter fluid, WD40, etc at the rear where the crank exits the engine. Then do the same only spray into the flywheel area up front - if either results in an increase in RPM's, that seal is leaking (easiest to do with 2 sets of hands). Seals are around $6-10 each, and provided the flywheel doesn't hold on for dear life *too* bad, it's about an hour job total. You'll need to make a clutch puller (there are many threads on that here) and You'll need a small-engine flywheel puller, other than that a little blue loctite to schmear on the seals when reinstalling them and it's all simple hand tools.

[van the man]

Oh okay I thought I would have to pull the engine. I hope the bearings are okay. Looking online, those seals are pretty inexpensive.
I wonder if a 250 dirt bike exhaust would fit in there somewhere? I used to be a pretty good tig welder back in the day...

[BrewCityMusic]

Well, in all honesty - You *should* figure on pulling the engine - it's literally one plug, 2 cables, one fuel line, roll off a belt, and 4 or 6 bolts (I haven't done a Marathon 2-stroke in awhile but it's literally 15min out and about the same in) ... The whole shebang with the clutch is around 50lbs so it's an easy one-man job, and believe Me - pulling the clutch and flywheel goes a LOT easier on a bench, as well as the seals. You're going to end up mangling the old ones prying them out, and it's a lot easier to get into prying position on a bench (plus it'll be much easier to clean up and replace them too).

Do a little poking around, there are quite a few older threads regarding other exhausts people have used on the 2-strokes, the main drawback of course is the noise level of other styles (GC exhausts are VERY much "overkill" but most actual "golfers" appreciate that on the course - remember, these were actually USED for golf at one time, LOL) ... A few other tricks exist to improve performance but most of them are minimal improvements, running a shorter belt is a HUGE difference though so search that one too once You get your engine sorted out. Keep us posted how things are going, there are always people around willing to answer questions and lend experience if needed!

[van the man]

Okay so I sprayed wd40 around crank seals didn't run any different. Just for kicks i pulled the driven clutch cover and the buttons on the inside (not the cap side) were shaved off! So I ordered the 3 I needed (about $10 ea!!!!) , pulled the clutch (fell right off the shaft), took it apart and drilled out old buttons, replaced w/new, put it all back together. It's A LITTLE better. No adustment of this clutch, can't change preload. So now I'm wondering if there is any adjustment to the comet drive clutch?
Also, I couldn't find a shorter belt for the to 87 2 stroke. Anybody find one?

[BrewCityMusic]

Dayco HP3004 ... Just to make sure before You order, your cart should now have a 45" long belt, if so then the Dayco is Your Huckleberry at 44.125" long

[van the man]

Just for fun I removed the header pipe to see what the piston looked like and oh crap I can see the piston port. Should be on the intake side? Sure would explain a lot.

[cart around]

That's something to remember when others do future troubleshooting.

Sometimes they manage to run a little with the piston in backwards.