just got an 85 gas marathon

[racin161]

BREW do you need directions to the hardware store or am I going to have to send a screw. Inside joke ya'll

[bignate524]

Okay I performed the tests you wanted me to do and I am pretty sure that neither one of them changed the rpms at all and it kept turning over at the same speed. I have the battery sitting on the charger and i'm going to let it charge over night although i do not think that is going to fix my rpm problem....next test please? lol.

I also just ordered a tune-up kit for the cart because the previous owner told me it needed one. Another thing I did not mention is that the clutch part where the pin sits on top of the cap thing isn't connected and i am missing the pin cap thingy, i dont know if that could be the problem but it was running fine without up until this point we are at now....?

[BrewCityMusic]

racin, you keep crackin me up, hahahahaha - I actually DID replace the screw, but da**it, I'm gonna find the old one and put it back in JUST in case anyone ever has to see a pic of the engine compartment again :)

Alright, back to the issue at hand ... No change at all, hmmmm ..... Big POP, suddenly no power ... This is going to be a longshot, but do you have a compression tester? I ask because I just did a top end on my cart due to a slightly holed piston, I still had a touch of compression (enough to move the cart with one person, but only at 1-2mph and that was iffy at best) - and it turned out to be a nice little pencil-sized hole in the piston. I don't want to scare You at all, Amigo, but seriously, the next logical test would be compression providing the seals didn't show as bad.

Anyone else have a better "next step" ?!?!

JUST for fun, there's an outside chance this may work - see where your exhaust pipe bolts to the muffler itself? Try loosening those bolts and allowing a gap between the two of say 1/4" - it's going to be loud as he**, BUT try it, see if it runs better, there's a chance (albeit small) that the backfire blew a baffle in the muffler or possibly dislodged some poo-poo that's been collecting in there since 1985, it's not a *normal* situation for a good backfire to cause such a catastrophic muffler failure, but it's definitely NOT unheard of ....

Try the muffler thing, get ahold of a compression tester - that's about all I can come up with tonight other than a REAL longshot, which would be to pick up a new $4 spark plug and give it a try (REAL slim chance a good backfire would screw up the plug enough to cut power to that extent) .... CUE DAVE BOX .....

[BrewCityMusic]

OH = the clutch-pin-cap-etc thingee is your governor system, LOL - and it's fine if it's disconnected as long as you don't pound the heck out of the cart. All it really does is keep you from over-revving the engine which is actually pretty hard to do unless you're giving it wide-open-throttle downhill, etc .... The cap on the clutch is a good (read: IMPORTANT) thing to have though as it will keep you from dealing with clutch issues due to contamination, intrusion, and general "crap" in the future - but that's $11 you can spend anytime, let's get you through the initial :WTF" that seems to be going on first.

Again, Dave ?!?!?!

[bignate524]

Ok I plan on doing the compression test tomorrow sometime hopefully...i have read in a lot of posts that the pressure is supposed to be 120psi or at least over 100psi? is that correct for this pencil sized hole your talking about? is this is the problem will the next step be to buy a new piston set?
Placed my order with Buggies for a tune-up kit (new filters and new spark plug, as well as a new top end gasket set).

[1fast67]

100 psi is usually the lowest you'd want. Under that it usually doesn't want to run.

Sent from my LG-P999 using Tapatalk 2

[bignate524]

If it is under 100psi is that when it usually does what mine is doing....which is running extremely slow, drive belt turning very slow and cart has barely any rpm???

[BrewCityMusic]

Actually, there's no "set" compression cutoff for running, when I recently holed my piston I tested at just under 60psi and believe it or not, it *would* start and run at idle, no more, and actually ran in reverse enough to weakly move the cart ...

Generally from what I've seen, anything under 90 or so *will* cause you definite power and running issues, let's see where yours is at and go from there. For the record, the gradual failure of my piston started with a backfire and from there the symptoms were lack of power (which became exponentially worse over the course of that afternoon until it would idle, no more, as described above) - but again, a compression test will do wonders to ascertain where we troubleshoot from here.

Fingers crossed on 100lbs plus, Amigo !!!

Just for fun, grab the drive belt and ensure it has the ability to slide freely when the cart is off - I did some thinking on this last night and there's also an outside chance the clutches could be acting up or the belt has bound, etc - might not hurt to roll the drive belt off the clutches (in other words remove it) and try starting the cart, see if that has any bearing on the engines ability to rev up

[Dave Box]

It's always difficult to diagnose an issue by remote control but as usual Brew City is on the money. Referring to your picture of the carburetor it looks like the person who rebuilt the engine has made the mistake to which Brew City alludes. The throttle cable is indeed lacking the return spring and this will cause backfiring. If you look at the cable on the left which is the governor cable someone has left a fair amount of slack in it which compensates for the lack of the spring. The throttle cable should have approximately 1 inch of spring tension and the governor no slack. Not only does this allow the governor to work but it ensures that the throttle butterfly is tightly closed when your foot is off the throttle. The way your engine works is that with your foot off the gas the engine ignition is turned off but if the throttle butterfly is slightly open the engine will suck in a small amount of gas which will collect in the exhaust pipe. When you press the throttle the engine will start and ignite the gas in the pipe causing the loud backfire.
Your first step will be to fit a spring (the spring from a click ball point pen works well). Follow Brew's excellent narrative for adjusting the microswitch and the butterfly and then we can find where your power has gone. From painful experience I can tell you I have been through the same thing just hours after rebuilding my 2PG. In my case I blew the rear seal out and I could actually see it between the engine and the clutch. The seals maintain the pressure in the crankcase and that pressure operates the fuel pump so a quick test is to remove the spark plug lead so it will not start, remove the fuel line to the carburetor and crank the engine. You should see a big healthy pulsating jet of fuel. A dribble or a trickle will not work.
Finally there are many guys here who truly enjoy helping out fellow 2PG owners so we will get you running.

Dave

[bignate524]

Yeah I am really happy with the help I have gotten already with my new cart! I'm hoping we can get this thing running asap. I am going to do the compression test in about an hour and a half after I get some other things done. Hopefully it's a fairly easy fix and the cart can get back moving, me nd my brother bought it so we could take it down to our campground and cruise around so nothing super big or anything. I'm hoping it's not a costly repair, but I guess a couple hundred wont hurt in order to get it working again lol :/