Weird issue, cart won’t stay running

[CP241]

The valves look good, but almost "too" good. Has the motor been rebuilt recently? Do you have the compressiom tester still? Put about a pop bottle cap worth of motor oil in the spark plug hole.and recheck compression. Id like to know if it comes up a lot.

Those valve adjustments look "too" good to me (assuming they are adjusted correctly). I'm thinking someone has been in there before, did enough work to get it to "run" so they can sell it, and unfortunately that happens a lot with Craigslist and Facebook.

Did you buy it running or know it had problems when you bought it?

[Largemouth21]

Originally Posted by CP241

The valves look good, but almost "too" good. Has the motor been rebuilt recently? Do you have the compressiom tester still? Put about a pop bottle cap worth of motor oil in the spark plug hole.and recheck compression. Id like to know if it comes up a lot.

Those valve adjustments look "too" good to me (assuming they are adjusted correctly). I'm thinking someone has been in there before, did enough work to get it to "run" so they can sell it, and unfortunately that happens a lot with Craigslist and Facebook.

Did you buy it running or know it had problems when you bought it?

I had to return the compression gauge, I think it’s a valve related issue. When it runs it doesn’t smoke or anything. I think it might’ve had work done, my boss said the previous owner said it was serviced at an ez go dealer for a no run issue. My boss then bought it soon after and used it for 3 months and it ran fine although towards the end was running rough. Then in the spring it would start but barely run at all. Was put in the woods for 2 years and recently dragged out and here we are. It’s possible there was a service done.

[CP241]

My thinking is that someone has rebuilt thr engine and maybe didn't do it right. Unless you've got a valve seat problem or something, I'm thinking they may have used stock size rings and it should have been overbored.

You can have weak, incorrectly installed, or worn rings and not smoke. Different rings do different functions. Some control oil and some do compression. Ive has motors with super low compression that don't smoke a bit. And I've had motors with perfect compression that smoke like a train.

Bottom line here, your compression is WAY low. We can speculate all day, but the only way you'll know for sure is to pull the engine, start taking it apart and measuring things. Whatever it is will be quite obvious.

But a bit of oil in the spark llug holes, and if compression jumps up its definitely a ring issue. If it doesn't change anything it could be valves, head gasket, or even incorreftly torqued head bolts

[Largemouth21]

Originally Posted by Largemouth21

I had to return the compression gauge, I think it’s a valve related issue. When it runs it doesn’t smoke or anything. I think it might’ve had work done, my boss said the previous owner said it was serviced at an ez go dealer for a no run issue. My boss then bought it soon after and used it for 3 months and it ran fine although towards the end was running rough. Then in the spring it would start but barely run at all. Was put in the woods for 2 years and recently dragged out and here we are. It’s possible there was a service done.

Just pulled the timing cover off, cam timing is spot on. What should I check next? Just so weird that it runs sometimes and sometimes not. I also am not 100% sure about the compression reading, the gauge was kinda sketchy and seemed to lose pressure over time, like the 60 psi would bleed to 0 if I left it long enough. I had to tighten a fitting to get it to keep a reading. Once again when it ran it ran fine

[Largemouth21]

Originally Posted by CP241

My thinking is that someone has rebuilt thr engine and maybe didn't do it right. Unless you've got a valve seat problem or something, I'm thinking they may have used stock size rings and it should have been overbored.

You can have weak, incorrectly installed, or worn rings and not smoke. Different rings do different functions. Some control oil and some do compression. Ive has motors with super low compression that don't smoke a bit. And I've had motors with perfect compression that smoke like a train.

Bottom line here, your compression is WAY low. We can speculate all day, but the only way you'll know for sure is to pull the engine, start taking it apart and measuring things. Whatever it is will be quite obvious.

But a bit of oil in the spark llug holes, and if compression jumps up its definitely a ring issue. If it doesn't change anything it could be valves, head gasket, or even incorreftly torqued head bolts

The funny part is that it was taken to an ez go dealer by the previous owner lol. What you’re saying makes sense, I will start with that. I’ll have to get another compression gauge though. Can you please try and explain to me why it’ll run after it’s sat for a while but will die after 1/4 mile? When it runs it runs fine I just don’t understand how it runs fine sometimes with low compression

[CP241]

Thermal expansion rates of different types of metals in the same area can cause compression loss with heat. You can easily confirm rings by doing a wet compression test (oil down the hole). The oil helps to seal worn rings better so compression will increase.

As for the dealer comment, that really doesn't mean anything. Gotta think of it like this... it ran then. It doesn't now. It doesn't mean what's wrong now has anything at all to do with what was wrong with it then. It may be related, maybe not. The best thing you can do is start from scratch and ignore anything ever in the history prior to now. I do the same thing anytime I buy a cart, running or not. I dont care what they've done in the past or not. Id rather just get it home and figure it out myself. 9 times out of 10 they're wrong anyway.

[CP241]

were happy to help you figure it out and get it going. Just gotta do the basic tests first so we know exactly what we're dealing with

Otherwise without the diag, its equivalent to going to the doctor, saying you feel sick and 6 months ago you had the flu, and expecting an accurate diagnosis. :)

[Largemouth21]

Originally Posted by CP241

Thermal expansion rates of different types of metals in the same area can cause compression loss with heat. You can easily confirm rings by doing a wet compression test (oil down the hole). The oil helps to seal worn rings better so compression will increase.

As for the dealer comment, that really doesn't mean anything. Gotta think of it like this... it ran then. It doesn't now. It doesn't mean what's wrong now has anything at all to do with what was wrong with it then. It may be related, maybe not. The best thing you can do is start from scratch and ignore anything ever in the history prior to now. I do the same thing anytime I buy a cart, running or not. I dont care what they've done in the past or not. Id rather just get it home and figure it out myself. 9 times out of 10 they're wrong anyway.

Ok you’ve been super helpful and I’m grateful. So I’ve done some digging and we are considering buying a new motor. I just found out previous to us owning it, the kart was used to pick TWO different HUGE golf courses since it was new. Apparently it has a TON of hours on it. So it’s not surprising the motor is worn out. We also don’t have all the tools for a rebuild, (ring compressor, valve spring compressor, etc) so buying all the tools needed would add up as well. Is there anywhere I could get a used motor? My boss doesn’t want to mess with rebuilding it

[trig123]

Originally Posted by Largemouth21

Ok you’ve been super helpful and I’m grateful. So I’ve done some digging and we are considering buying a new motor. I just found out previous to us owning it, the kart was used to pick TWO different HUGE golf courses since it was new. Apparently it has a TON of hours on it. So it’s not surprising the motor is worn out. We also don’t have all the tools for a rebuild, (ring compressor, valve spring compressor, etc) so buying all the tools needed would add up as well. Is there anywhere I could get a used motor? My boss doesn’t want to mess with rebuilding it

Motors & More located in Appling, GA
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[Largemouth21]

Ok guys I have an update: got the rebuilt motor back, 180psi in both cylinders, still won’t start. I can get it to pop a little but the spark seems very weak. All grounds I could find have been sanded and tested for continuity. Just to get an idea I pulled over a Honda gx160 I had laying around, very very bright blue snapping spark. Made the golf carts spark look like nothing (although it is blue as well) tested coil, primary is 4 ohms and I for the secondary I got 7.68 on the 1000 setting. I am sure the pulsar is good because I am getting spark. The plugs seem to always come out wet though and I get puffs of white smoke out exhaust when cranking I am strongly considering the HEI mod, I think either the coil or the ignitor must be bad since the spark is so weak? Any advice