97 GTX acting weird

[billstoys]

Hey everyone!

It's been awhile since I've been on this site but I am helping a friend work on his 97 GTX and it's acting up in a way I can't figure out.

It's a 787 tired motor but compression is 145 on both cylinders.

Grey gas lines replaced.
Fuel shutoff valve replaced.
Carbs completely rebuilt
gas vents replaced.

When you take it out first thing off the trailer it runs great for as long as you want. Idle, acceleration all fine. When you stop for awhile and let it sit you go back and it will start right away but will not accelerate until you tool around at idle for awhile. It will run fine after you give it some time at idle. Then after awhile it will start to bog and not go past 5000 rpm and finally die and not restart. Has done this 2 times now.

Spark plugs look good. Gas system looks good. Pop offs are set at 34 psi.

Any ideas????

 

[j.harris]

Did you leak test the needle and seats? Sounds like fuel it leaking past the needle and seat after it sits for a while.

 

[billstoys]

Well I went through it tonight.

replaced everything in the carbs with OEM parts.

set the pop offs at 34. Re synced the carbs, set the oil pump.
It started on ran very well on the trailer.

I will have to get it on the water and see what happens.

This being said when I shut it off I here something like I little piece of something rattling around the front cover by the stator. Checked the voltage at the battery at 5000 rpm and it was putting out only 12.9 volts.

is this within spec? How do I check the stator?

that nice makes me think something is about to let loose.

thanks

Bill

 

[etemplet]

Ouch. If the starter isn't loose I'd pull the mag cover. I hope it isn't your crank bearing. There isn't a whole lot in there to rattle around. These are pictures of the mag cover, mag housing and mag crank bearing. This one is bad. Good Luck....

 

[billstoys]

This is not my machine. So my friend who will remain nameless lol. Put all the cheapest parts he could find on eBay to make this thing run.

Now that you mention it...... He did replace the starter with one of the $60 dollar pieces of you know what. I wonder if what I’m hearing is a piece of the starter gear. I will check and see. Doesn’t sound like a bearing more like a tiny piece of something loose if that makes sense lol.

Thanks for the responses

Bill

 

[etemplet]

LOL... ya never know... hope it is indeed something inexpensive.

 

[GGuillot]

Checked the voltage at the battery at 5000 rpm and it was putting out only 12.9 volts.

is this within spec?

It's a little low, but not out of the ordinary when you first crank it up. especially if you have a battery that's not 100%. I have a volt/amp gauge on my GSX, so I can tell you don't be alarmed, if you run it for a few minutes or more it should start creeping up.