EZGO TXT 350 swap something seems off

[Betaguy]

Looking for some input on my 350 swap. I have a fresh rebuilt 350 with 295 head. Cylinders were bored for one size over pistons, new rods, new valves, and all bearings and gaskets. I picked motor up from shop and it was on test stand. I saw it on initial run and ran great. Seemed to rev up quick with good throttle response. It had stock clutch on it with stock 295 carb.

I brought it home and put it into my cart and doesn't rev nearly as fast. Actually seems to bog if I give it quick acceleration. I raced my neighbor who has same size lift and tires but only has a 295 and he smoked me. I was hoping my new motor was going to be better. I Havent had much time since installing motor to mess with it. I swapped carbs with another motor I had and no change. I'm running #90 main jet with stock airbox. I don't know if it is fuel or spark related or something else. Any and all help is greatly appreciated.

For all of you with a 350 and 295 head, how do they compare to a stock 295?

[trig123]

I don't think I would be racing it just yet. Let that engine break in some before you try and get it faster.
Then check to see if your linkage on carb is opening wide open. Turn key to off and push pedal to wide open. See if you can move the throttle any more ?
You can install a 1 inch shorter belt to get my torque also.
Remove driven clutch to see if ramps are worn out. If so take it apart and rebuild it. Cost is cheap. You just need to make a tool to do it with.
It don't matter how much hp you get out of these engines the rev limiters is going to shut it off at around 3700 or 3800 rpms which is good. Otherwise you would blow it up. I think the 1991 and 92 ezgo came without the rev limiter built in ignitor.

[Betaguy]

Originally Posted by trig123

I don't think I would be racing it just yet. Let that engine break in some before you try and get it faster.
Then check to see if your linkage on carb is opening wide open. Turn key to off and push pedal to wide open. See if you can move the throttle any more ?
You can install a 1 inch shorter belt to get my torque also.
Remove driven clutch to see if ramps are worn out. If so take it apart and rebuild it. Cost is cheap. You just need to make a tool to do it with.

I had a few hours of taking it easy. When I say we raced, we did one run from a stop to full speed. Lol

Throttle is going to wide open and I already have a 1” shorter belt with a 28 degree driven clutch. The driven clutch is off the workhorse I bought to steal the 350. I have a new driven clutch ordered because this one does have a lot of time on it, but seems to be functioning fine. I don’t believe it’s in the clutches though because in neutral it doesn’t perform well either. Revs up slower than normal,bogs if I push pedal down quickly it bogs out, and won’t start with out choke most of the time. I removed both jets and they were spotless. I cleaned carb in sonic cleaner. Has new fuel filter, new lines and fresh fuel.

[trig123]

Did the person who built have experience with these engines ? Reason I ask is it very easy to get the timing belt out one notch . It will do what yours is doing if yours is out time that one notch.

Have you got the OEM carburetor installed or the $20 ebay version ?

This is the Pre-MCI engine ?

Check the compression to see what its got. Disconnect one of the small wires on coil if its the pre-mci and make sure the throttle is wide open ( very important ) and spin it over.

See what the reading is on both cylinders. It can be out of time one notch and not really affect the compression reading but it would be nice to know what your rebuilt engine is showing.

Most of the time the compression will go up as it breaks in. You want to see 170 pounds .

[Betaguy]

Originally Posted by trig123

Did the person who built have experience with these engines ? Reason I ask is it very easy to get the timing belt out one notch . It will do what yours is doing if yours is out time that one notch.

Have you got the OEM carburetor installed or the $20 ebay version ?

This is the Pre-MCI engine ?

Check the compression to see what its got. Disconnect one of the small wires on coil if its the pre-mci and make sure the throttle is wide open ( very important ) and spin it over.

See what the reading is on both cylinders. It can be out of time one notch and not really affect the compression reading but it would be nice to know what your rebuilt engine is showing.

Most of the time the compression will go up as it breaks in. You want to see 170 pounds .

Yes very experienced Robin engine builder. He built the motor of my neighbors I raced too. I don’t believe it’s the motor itself because I saw it run on his test stand.

It’s a pre mci with oem carb

[Betaguy]

Originally Posted by trig123

Did the person who built have experience with these engines ? Reason I ask is it very easy to get the timing belt out one notch . It will do what yours is doing if yours is out time that one notch.

Have you got the OEM carburetor installed or the $20 ebay version ?

This is the Pre-MCI engine ?

Check the compression to see what its got. Disconnect one of the small wires on coil if its the pre-mci and make sure the throttle is wide open ( very important ) and spin it over.

See what the reading is on both cylinders. It can be out of time one notch and not really affect the compression reading but it would be nice to know what your rebuilt engine is showing.

Most of the time the compression will go up as it breaks in. You want to see 170 pounds .

Yes very experienced Robin engine builder. He built the motor of my neighbors I raced too. I don’t believe it’s the motor itself because I saw it run on his test stand.

It’s a pre mci with oem carb

[Rooster59]

Pretty easy to rev quickly on the test stand if nothing else is hooked up, like the clutch, belt, driven belt, and a 800 pound cart.

Did it have the air box and filter on it?

[Betaguy]

Originally Posted by Rooster59

Pretty easy to rev quickly on the test stand if nothing else is hooked up, like the clutch, belt, driven belt, and a 800 pound cart.

Did it have the air box and filter on it?

Clutch and starter belt were on it while on test stand. I can’t replicate it in cart without drive belt on.

It did not have air box on it. I have removed those and no change.

[Rooster59]

When I explored the 295/350 hybrid it seems to me the 295 takes a 90 main jet and the 350 takes a 92 but you should check that. Don't trust my memory.

[Betaguy]

Originally Posted by Rooster59

When I explored the 295/350 hybrid it seems to me the 295 takes a 90 main jet and the 350 takes a 92 but you should check that. Don't trust my memory.

295 takes a 80 0r 86
350 takes 90

I'm using 350 carb with 90 main