wont run at high speed after bad gas

[Strahm]

Re: wont run at high speed after bad gas

my carb looks identical to the carb diagram in the thread on this forum titled. whats this in my carb. http://forums.iboats.com/showthread.php?t=550876

it says it is off of a 1973 150hp. but it appears to be the same carb i have on my boat.

 

[Chris1956]

Re: wont run at high speed after bad gas

Strahm, An inline six motor is simply two more cylinders and one more carb than your motor. The pistons and cylinders are the same, as are the carbs. The carb jets may be a bit different, however. A lot of the Merc In line motors are simply 2 cylinder motors stacked up to create four or six cylinder motors. They share many parts between 90HP - 150HP.

 

[Strahm]

Re: wont run at high speed after bad gas



hopefully that picture helps.

also i checked the plugs again, and for the third time the top two plugs have been dirty, as in a slight grime sitting on them. and the bottom two have been perfectly clean.

i cut a few inches off my fuel line from the tank, and split it open, it appears to be fine, no deterioration, or anything of the sort

 

[Strahm]

Re: wont run at high speed after bad gas

i pumped some gas from the fresh tank into a mason jar, had no rust, no water, and was clear (blue tint from oil of course)

pumped some from the old tank that started this problem, and it didnt have rust or water, but it was so murky i couldnt see through it at all.

so i have confirmed that it was bad gas.
and the seafoam treatment has helped quite a bit, i just cant get the last bit the clear out.

 

[Chris1956]

Re: wont run at high speed after bad gas

Those are backdrag carbs. See the little yellow tube? Air is pulled thru that tube to lower the pressure in the carb bowl, leaning the fuel/air mix a bit. Remove the brass elbow that the fuel line is connected to and you should find a stainless steel screen. it may be clogged.....

 

[Strahm]

Re: wont run at high speed after bad gas

ok thank you very much. i will check that asap.

i just ran the boat, and it appeared to be back to normal or very close. it was hard to tell though as it is extremely windy and wavy today.

regardless i will check the screen under the fuel inlet.
thanks a lot, i would have never found that without your advice.