Gas, Compression and Spark, won't run

[Ryan_j_02]

First time post. I have 2001 ezgo txt. Just did full rebuild. It ran for about 2 min. (Up and down driveway. Ran out great at about 1/4 throttle. Didn't want to run very well with accelerator all the way down. Switched carbs and same thing. Let it sit a day, now it won't fire at all. It has 130psi compression, fuel is getting to plugs and it will arch nice and Blue with a head check on the plugs. Plugs are also new. Timing is spot on and valves are .005. What the heck am I missing? It ont even fire when fuel put directly into intake. Not even a hiccup or cough. Any help?

[Ryan_j_02]

Anyone?

[Michael Eddie]

When your valve lash is out, your engine can start acting up, spitting, sputtering, even backfiring.

Disclaimer: (for readers experiencing a similar problem, before you dive into adjusting the valve lash, hold your horses, especially if you haven't done a full rebuild or replaced the valve seals yet, I would thoroughly check fuel delivery and carburetor instead)

Here's a trick I've used with rough running after adjusting the valve lash: Touch those valves gently against the cam, then back them out a quarter turn. Thats it. Now about those wet plugs, I know you've checked for spark, does the choke make any difference? With today's fuel blend, carburetors can gum up fast, especially if any of those carburetors had ever been sitting with fuel in the bowl. My advice? Take that carb and jets completely apart, soak it, clean it thoroughly. Consider investing in an OEM carburetor from EZGO. Aftermarket ones may claim to be tuned the same, but trust me, they're never quite dialed in like the real deal. Keep us in the loop.

[Ryan_j_02]

Choke makes zero difference. No spitting, sputtering or firing of any kind. Seems to me that it is not sparking while plugs are installed? Plugs wet would tell me fuel is getting to them, also doesn't fire when fuel is squirted directly into intake. Could it be possible that it isn't firing inside the head but will outside?

[golfcartg]

Choke makes zero difference. No spitting, sputtering or firing of any kind. Seems to me that it is not sparking while plugs are installed? Plugs wet would tell me fuel is getting to them, also doesn't fire when fuel is squirted directly into intake. Could it be possible that it isn't firing inside the head but will outside?

What you'll want to do is grab a test light and connect it to both the positive and negative terminals of your ignition coil. Now when you crank the engine using the starter, keep an eye out for that light. It should be blinking on and off. If it's not blinking at all, then you could have a spark issue and we'll need to backtrack a little. If it's just staying steadily lit without any blinking, then we'll have to investigate the igniter and pulsar coil and troubleshoot from there. Just remember, that light needs to be flashing for the spark to kick in.

[Ryan_j_02]

What you'll want to do is grab a test light and connect it to both the positive and negative terminals of your ignition coil. Now when you crank the engine using the starter, keep an eye out for that light. It should be blinking on and off. If it's not blinking at all, then you could have a spark issue and we'll need to backtrack a little. If it's just staying steadily lit without any blinking, then we'll have to investigate the igniter and pulsar coil and troubleshoot from there. Just remember, that light needs to be flashing for the spark to kick in.

So if it sparks while out of head then would it not spark when inside? I have 3ohms on the spade connections on coil.

[golfcartg]

So if it sparks while out of head then would it not spark when inside? I have 3ohms on the spade connections on coil.

It sounds like your spark system is holding up well, which is a relief. It could be that your carburetor needs a bit of fine tuning or it's just not quite up to par if it's a low quality aftermarket, the jets could be clogged with microscopic gunk and the engines getting flooded with gas. I would look into maybe a more precise valve lash setting using Michaels method above. Also double check that all intake gaskets are snugly in place and properly sealed, double check the spark plugs themselves are not fouled. Hang in there, patience is key when it comes to tackling these issues

[Ryan_j_02]

It sounds like your spark system is holding up well, which is a relief. It could be that your carburetor needs a bit of fine tuning or it's just not quite up to par if it's a low quality aftermarket, the jets could be clogged with microscopic gunk and the engines getting flooded with gas. I would look into maybe a more precise valve lash setting using Michaels method above. Also double check that all intake gaskets are snugly in place and properly sealed, double check the spark plugs themselves are not fouled. Hang in there, patience is key when it comes to tackling these issues

I have tried 2 different carbs to the same result. Freshly cleaned stock carb and an aftermarket. Seems to me that it would at least attempt to fire. Especially when I have sprayed directly into intake and nothing. I have checked valve lash twice and timing twice...this thing is driving me crazy. The plugs are sparking on head so I wouldn't think they are fouled out. What am I missing?

[RideonTractor]

Howdy Ryan, let's break it down real simplelike. When was the last time your cart was runnin wild? And how did it get here? Boy them folks who chimed in earlier threw out some mighty fine suggestions. Besides that, thinkin bout old gas in the tank or water sneakin in with it, and here's a couple other things to check..

Could be them piston marks are flipped round the wrong way when you done rebuilt it. And that timing belt? Well if its off by just one tooth, it can mess up the whole show.

Now, I get it, this problem got you pullin your hair out. Sometimes, it's like tryin to solve a puzzle without all the pieces. If it's gettin too much, ain't no shame in draggin it up on the trailer, paying the $150 diag fee, and lettin the dealer take a crack at it. They might save you from a whole lotta future headache. Anyways. If you need anything else, just give a holler.

[Ryan_j_02]

Howdy Ryan, let's break it down real simplelike. When was the last time your cart was runnin wild? And how did it get here? Boy them folks who chimed in earlier threw out some mighty fine suggestions. Besides that, thinkin bout old gas in the tank or water sneakin in with it, and here's a couple other things to check..

Could be them piston marks are flipped round the wrong way when you done rebuilt it. And that timing belt? Well if its off by just one tooth, it can mess up the whole show.

Now, I get it, this problem got you pullin your hair out. Sometimes, it's like tryin to solve a puzzle without all the pieces. If it's gettin too much, ain't no shame in draggin it up on the trailer, paying the $150 diag fee, and lettin the dealer take a crack at it. They might save you from a whole lotta future headache. Anyways. If you need anything else, just give a holler.

Right after rebuild, the cart would rev right out but only at 1/4 throttle. I left it for the night and now nothing. Gas is fresh and I am pulling from a gas can, not the fuel tank. (Tried both, no change) I made sure my letters where up when installing the rings. And I have checked timing 3 times now and everything looks correct per the manual. I may just have to get the dealers to take a look, but want to figure this out on my own. Has to be something stupid I would think. It just doesnt make sense when I have timing, spark, fuel and compression.

[Michael Eddie]

I was reviewing this post and something stuck out at me. I noticed you previously mentioned compression 130psi, and I like to think that only a few pounds off shouldn’t create a no-run situation. However, for a freshly rebuilt engine, you should be pushing over 150 psi or more. It’s important to consider a range of factors that could affect compression even with meticulous attention to detail, that can lead to compression loss.

Valve seating can be a precise process, any minor imperfections or debris can prevent a proper seal leading to reduced compression. Similarly incorrect piston ring installation can cause poor sealing, even if the rings themselves are new and undamaged. Any slight scoring, glazing, or out of round conditions on the cylinder walls can prevent the rings from sealing properly. Even a new head gasket can fail if not installed correctly or if the head and block surfaces aren't properly cleaned, prepared and tightened down. Always consider the possibility of unseen cracks in the cylinder head or block, which might not be evident during the rebuild process but can lead to compression loss once the engine is running. Just something to consider.