G9 running, but won't throttle up - does engage into fwd and rev gear as it should

[raenglehart]

Alright fellas, I have a 1989 G9A that I've had for 5 yrs now. It was a non-running basket-case when I picked it up back them and I've gone thru it end to end over the time I've owned it.

Recently my 10 yr old daughter and friend were put-putting around the property with it and it began to not want to move for them. Of course I wasn't told this until I asked why the cart was sitting in the "back 40" a couple days later. I finally had a chance to look into it. I have it rigged to idle without pressing the peddle (been that way for a few years now - if I flip that switch to activate it). Anyhow, whether peddle activated or my switch, the starter will turn over and the engine "idling" (I know, that's not technically "idling"). I put it in Fwd or Rev and the cart will engage into gear and try to roll a little in whichever direction I shifted it in. This was about a month or so ago, so I hope I can remember everything below before higher priorities took precedence Keep in mind, the below is not necessarily in the order I accomplished

The issue: It will not rev in order to get the drive belt to engage and suck in the clutch.

- First checked/charged battery fully (not my first rodeo....lol)
- Tried using the jump start function on my charger (years ago, this verified my battery was going out on another cart even though it was taking charge and seeming to hold it's juice under a load test via a multi-meter) No such luck this time.
- swapped battery with a known new one from another cart I had at the time
- Traced wires out and cleaned up and re-secured all grounds.
- checked start/gen output voltage (good per what I read on here somewhere)
- I rebuild Stater/Gen maybe a year ago--probably less than 20 Oper hours in it since then.
- I have good spark (using an inline spark tester b/w plug wire and plug).
- swapped in a new coil, spark plug for S-n-G's (from spares I had lying around) I work on this sorta stuff a lot for friends/co-workers which leads to loads of spare parts sitting around...lol
- checked compression for S-n-G's, it was good (can't recall the PSI I read)
- I pulled the fuel line to check pump output. That is good. *I even swapped the fuel pump, lines and inline filter over from another cart I was working on at the time (it was awaiting parts for unrelated matters).
- removed intake hose and shot a littler starter fluid in the carb while working the throttle (cart rear jacked up on jack stands). That had no effect whatsoever.
- Air-box lid/latches, seals are all good (cracks have been known to cause weird things on other projects I've worked on (ATV's, carts, etc))
- Pulled the carb, disassembled, cleaned just for fun. Always run ethanol-free fuel with sea-foam added (that combo had never let me down yet)

It's something stupid-simple I'm over looking. I know there's been other things I've checked (thinking outside the box), I just can't recall as I type this up. I'll update if I remember anything later.

So, from the above, any ideas what to check next? I've spent quite a bit of time reading up on threads here that seem to be related, but either they just end with no resolution posted, or go off in left field talking about completely unrelated topics. This doesn't seem to me to be Yamaha G9 specific related as I've had issues like this on other branded carts as well over my years of tinkering on them. What is the "forest I'm not seeing for the trees" in this case?

Thanks,
Roger

[Spicyunicorn]

After a bit of turning it over and trying to start it is the plug wet or dry? I'd pull the valve cover off and make sure a push rod didn't pop loose from a rocker arm and while you're in there set valve lash

[cfherrman]

Is it running as in firing or is the starter generator just turning over the engine?

[ironmonkey17]

I was thinking the same thing a spiceyunicorn was, make sure a rocker didn't pop off..

[raenglehart]

Originally Posted by cfherrman

Is it running as in firing or is the starter generator just turning over the engine?

Yes, ignition coil is sending firing signal to the spark plug. I used an inline spark tester in b/w the plug and plug wire connector to verify that after doing the old fashioned pull plug and hold against block method.

Originally Posted by Spicyunicorn

After a bit of turning it over and trying to start it is the plug wet or dry? I'd pull the valve cover off and make sure a push rod didn't pop loose from a rocker arm and while you're in there set valve lash

Wet (Sorry, I knew I forgot to include something....lol). I'll pull the valve cover to verify the push rod.......thanks Spicyunicorn for the suggestion. I thought I had checked valve lash already, but now thinking back, that was another gas cart I was working on (for a neighbor) around the time this issue started with mine. Sometimes I get my many ongoing projects mixed up (lets call it brain gas - seems to be more frequent these days unfortunatley...haha)

[Cartmaster]

before you open up the top, just pull the plug and put your finger over the plug hole and crank the engine, you will soon know if you have a valve problem as it will not try to push your finger off, if thats the case then its top off time. and i dont mean remove your bra LOL.

[raenglehart]

Originally Posted by Cartmaster

before you open up the top, just pull the plug and put your finger over the plug hole and crank the engine, you will soon know if you have a valve problem as it will not try to push your finger off, if thats the case then its top off time. and i dont mean remove your bra LOL.

Hey, I can pull my top off if I want too

[Cartmaster]

where are my sunglasses?

[Spicyunicorn]

Originally Posted by Cartmaster

before you open up the top, just pull the plug and put your finger over the plug hole and crank the engine, you will soon know if you have a valve problem as it will not try to push your finger off, if thats the case then its top off time. and i dont mean remove your bra LOL.

If exhaust push rod pops off you will still have compression technically two compression strokes if it's not opening exhaust valve

[cfherrman]

Is it firing as in burning fuel?