Gamefisher 7.5 too much air

[alloffroad]

My 1980 gamefisher 7.5 hp with eska carb won't run at high speed unless the choke is half closed. I've adjusted the air/fuel screw from all the way in to all the way out, 1/4 turn at a time and it will idle good with it almost all the way out but no go at hi speed, or any throttle at all. It speeds up for just a second then dies down to off. I have cleaned the carb 2x but nothing coming out. carb cleaner and air. Any ideas?

 

[brim_buster]

very simple carbs. How did the fuel pump look? Does your carb have a high speed adjustment screw in the bottom of the carb bowl? How did the reeds look? Did you adjust the float properly?

 

[brim_buster]

 

[alloffroad]

Well to be honest... all looks good. The motor sat for a while before i got it. The carb was a little dirty in that i mean white powder and some varnish. I'm not an expert with 2 strokes but the reeds seem good. Not broken and still flexable. I rebuilt it so all the gaskets, pump, and needle seat are new. I couldn't find much about the float, but i adjusted it to near level with bowl seating surface then very slightly higher, with carb upside down, at the opposite side of the needle/hinge side. I'm pretty sure that float isn't correctly adjusted. Thanks for your response brim-buster. Continued assistance is most certainly appreciated.

 

[alloffroad]

Also the bolt holding the bowl on is not adjustable.

 

[brim_buster]

Did you replace the fuel pump bladder inside the face of the carb and its seated with the slit at 2-8 oclock? Like in the first pic I sent.

 

[alloffroad]

Yes. The orange pump is new and situated at 2 o'clock

 

[brim_buster]

With choke half closed you are cutting off air and making it run richer. Not getting too much air not getting enough fuel. Are you using an external fuel tank or the one on the motor? Add an inline small fuel filter to see if in fact you are getting a good fuel flow. Im gonna assume good compression and good spark?

 

[alloffroad]

I am using an external tank. I will try the built in tank to see if i get a better result. It has excellent compression although i dont remember the number but i will rerun that today and post it here. Spark is good and strong. Thank you again.

 

[alloffroad]

The built in tank has a new filter.

 

[alloffroad]

Compression is 95 psi dry. 100 psi after a table spoon of 10-30 motor oil

 

[alloffroad]

Upon further inspection the orange pump bladder was at 9 & 3. I rotated to 45⁰, adjusted the float slightly and reassembled. It seems to be running ok. A bit rough at high speed by much better

 

[alloffroad]

It is definitely slow on the upswing to higher rpms. Once there it runs pretty good but not very fast on acceleration. Any thoughts?

 

[brim_buster]

The pump bladder has to be set at 2 oclock. Just like the picture. It has to be close to dead on as possible. Other than that they arent really that fast to accelerate. Its just a lawn mower engine built to get you where you need to go and back. Your not gonna pull a tube or a skier with it LOL

 

[alloffroad]

Well...with that maybe it's as good as it's gonna get. How about the compression. Is that 90-95 psi ok?

 

[brim_buster]

Yes sir

 

[alloffroad]

Awesome news. Thank you very very much for your guidance brim. I feel much better about this little motor. Now the only problem is....water. we're about dry here in northern California.

 

[alloffroad]

Older thread that i started but no sense in starting a new one. Just an update. The motor runs great now. It sat all winter with sta-bil in it. I'll take it. Idles, accelerates and runs at top speed just fine. I messed with the air mixture screw and idle screw a bit. I changed the lower gear oil. Glad i did before using it because it was frothy milk color. Now i can't wait to use it.