140 johnson

[allengoins]

i have a 1978 140 johnson. i have rebuilt it and rebuilt the fuel pump and carbs while i was at it. The engine idles great and even takes off like a champ but after i get going it acts just like it runs out of gas. if i let off the throttle then i can stay on plane but it is only running about 3500 rpms. I've bypassed the fuel pump the ball and the gas tank to eliminate those. i rechecked the float levels in the carbs and made sure there wasn't any trash in the carbs or in the jets. I can't figure it out. i checked the fuel pressure with a gauge like my manual said. any help would be greatly appreciated

 

[emdsapmgr]

Re: 140 johnson

Sounds like the engine is running out of gas. When that starts to happen, pump the fuel hose ball and see if it will keep running high speed. If not, try running on a separate tank with different hose. In case you think the tank might have some water in it, take a fuel sample and put it in a clear glass.

 

[kenmyfam]

Re: 140 johnson

Fuel pump maybe ???? Do the bulb squeeze thing to check it out.

 

[allengoins]

Re: 140 johnson

Sounds like the engine is running out of gas. When that starts to happen, pump the fuel hose ball and see if it will keep running high speed. If not, try running on a separate tank with different hose. In case you think the tank might have some water in it, take a fuel sample and put it in a clear glass.

i've pumped the ball and it seems like it may help but not much i have used a seperate tank and even bypassed the ball. When i rebuilt the engine i emptied the gas tank and it had nothing in it when i put it back in the boat. And the fuel pump kept a constant 3lbs of pressure while running out of gas going down the lake

 

[wahoo 16]

Re: 140 johnson

sounds like my old 140, water in seperator or engine filter? dump them into stainless bowl and inspect.

 

[emdsapmgr]

Re: 140 johnson

When you have the rpm problem, do you have good spark on all 4 cyls?

 

[ezeke]

Re: 140 johnson

When you rebuilt the carburetors, were you careful to reconnect the float arms to the needles?

 

[allengoins]

Re: 140 johnson

there is no water in the gas i took the tank completely out when i rebuilt the engine and i have good spark and everything was put back into the carbs correctly

 

[allengoins]

Re: 140 johnson

the bottom carb that was on the engine is messed up. it has something inside of it not letting it get fuel to it. I've rebuilt it took it apart and did everything known to do. I had a guy let me borrow a carb and this fixed it. i was wondering if anyone had a bottom carb for a v-4 engine that i could buy

 

[ezeke]

Re: 140 johnson

Be sure to replace them as a set.

 

[Benny1963]

Re: 140 johnson

bunch of 140 carbs on ebay