80s Yamaha G1 full throttle goes slow

[Kevin90GSX]

Originally Posted by trentofdestiny

Is the plug dry or wet?


Sent from my iPhone using Tapatalk

Dry

[trentofdestiny]

Originally Posted by Kevin90GSX

Dry

Then you have a carb or fuel pump problem. Or maybe the crank seals but I would think that would affect your compression also.


Sent from my iPhone using Tapatalk

[Kevin90GSX]

Originally Posted by trentofdestiny

Then you have a carb or fuel pump problem. Or maybe the crank seals but I would think that would affect your compression also.


Sent from my iPhone using Tapatalk

Line coming off the top of the fuel pump is dry. I took off the fuel pump sprayed carb cleaner in it put back but fuel is still not being pumped in to the carb it seems.

[mikeasis]

Originally Posted by trentofdestiny

Then you have a carb or fuel pump problem. Or maybe the crank seals but I would think that would affect your compression also.


Sent from my iPhone using Tapatalk

crank seals do not affect compression. they would effect crank case vacuum which would effect the fuel pump.

[mikeasis]

Originally Posted by Kevin90GSX

Has spark and has 150 compression. Spark plug seems to have a clean burn.

150 seems high for a G1. Have you shaved the head or something?

[trentofdestiny]

Originally Posted by mikeasis

crank seals do not affect compression. they would effect crank case vacuum which would effect the fuel pump.

Ahh that's what I was thinking of


Sent from my iPhone using Tapatalk

[Kevin90GSX]

Originally Posted by mikeasis

150 seems high for a G1. Have you shaved the head or something?

Nope I have not and how can I check crank case vaccumm? Is that the line that goes to the underside of the fuel pump?

[mikeasis]

Originally Posted by Kevin90GSX

Nope I have not and how can I check crank case vaccumm? Is that the line that goes to the underside of the fuel pump?

yes its the line from the crank case to the carb. I would think you could put a vacuum gauge there but what type of reading youd have I have no clue.

Probably the best thing would be insert plugs in the intake and exhaust then either hook up a smoke machine or put a small amount of air into the crank case through that port and listen/look for leaks.

[Kevin90GSX]

Would there be no fuel at all in the fuel pump though? I'm tempted to buy a new fuel pump but they are about $90 but don't want spend that if my pump is fine.

Any other tests to determine if it's just fuel related vs seals?

[Kevin90GSX]

Also does anyone on here know anyone local who works on golf carts in CT?