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87 Mercury 150 HP 2stroke idles up then quits when given more gas

C

cws68

Contributing Member
Ok here is the story. Bought this 1987 bass boat with a Mercury 150 horse 2 stroke engine. sat long time. I had to change out fuel lines from tank to motor plus change out fuel/water separator completely. Was filled with brown water it's been so long and relocated to a better area for proper servicing.
Boat started and idled fine. took to lake to try out. ""upon giving it gas she picked up great"" then all of a sudden wouldn't take fuel anymore and stalled Started right back up no problem. Put in gear but again didn't want to take more gas but just a little. Whenever I went to push down for more fuel would be ready to stall out again so I brought it back to shore. NOW, when in neutral it would take gas and rev up.
Came home and changed lower gear oil. Was black as can be. She took 22 oz to refill but didn't seem to drain out that much.
I have read about engine refusing to take fuel in engine due to this. I never heard of it before and maybe all that it was. don't know yet.

I drained out all the old gas to be safe if someone used ethanol and put non ethanol in with mix of course after changing fuel lines. Since lines from tank to engine were so messed up, should I have changed on motor as well thinking something got clogged. Again in neutral no problems giving it gas, which leads me back to bad gear oil causing problem

WTH, HELP!
 
There is no load on the motor in neutral !!----They will rev up fine running on 3 of 6 cylinders.-----Lower unit oil has nothing to do with the bogging in my opinion.
 
faztbullet said:
Check spark and rebuild carbs with new kits and lines
Click to expand...
ok spark on all cylinder's so got that out of the way. open drain plugs on carbs and fuel came out clean. NOW the goodie I found was the old oil injector system was by passed but never capped. Now would this cause my problem since it would be sucking in air at the head?
Picture below. I now have them sealed off
 

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faztbullet said:
No
Click to expand...
OK, now my last question. I put new fuel lines on engine. I was always told to make them the same length. This picture shows new line coping old line. I would think this would cause air pocket maybe when accelerating. It was strapped off this way as well, then goes between carbs to the other side to fuel pump.
Could this be causing a problem as well.

Thank you again for all your time on these matters
 

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cws68 said:
Ok here is the story. Bought this 1987 bass boat with a Mercury 150 horse 2 stroke engine. sat long time. I had to change out fuel lines from tank to motor plus change out fuel/water separator completely. Was filled with brown water it's been so long and relocated to a better area for proper servicing.
Boat started and idled fine. took to lake to try out. ""upon giving it gas she picked up great"" then all of a sudden wouldn't take fuel anymore and stalled Started right back up no problem. Put in gear but again didn't want to take more gas but just a little. Whenever I went to push down for more fuel would be ready to stall out again so I brought it back to shore. NOW, when in neutral it would take gas and rev up.
Came home and changed lower gear oil. Was black as can be. She took 22 oz to refill but didn't seem to drain out that much.
I have read about engine refusing to take fuel in engine due to this. I never heard of it before and maybe all that it was. don't know yet.

I drained out all the old gas to be safe if someone used ethanol and put non ethanol in with mix of course after changing fuel lines. Since lines from tank to engine were so messed up, should I have changed on motor as well thinking something got clogged. Again in neutral no problems giving it gas, which leads me back to bad gear oil causing problem

WTH, HELP!
Click to expand...
I had the same thing going on for about the same reasons. I have EFI system. My high-pressure pump has a fine micron filter on the bottom of the pump. SO, at a slow speed there was enough fuel getting to the pistons, but when trying to speed up, not enough fuel flow was getting to cylinders. I also had to replace the water separator filter again after cleaning out the fuel system. Hope this will get you going in the direction water again.
 
p2aquasport said:
I had the same thing going on for about the same reasons. I have EFI system. My high-pressure pump has a fine micron filter on the bottom of the pump. SO, at a slow speed there was enough fuel getting to the pistons, but when trying to speed up, not enough fuel flow was getting to cylinders. I also had to replace the water separator filter again after cleaning out the fuel system. Hope this will get you going in the direction water again.
Click to expand...
Thanks, I changed the whole fuel system, checked psi on all cylinders to make sure all was good. I'm in process of rebuilding all 3 carbs and fuel pump to be sure ALL have been updated and good to go.
Even redoing bottom end so be ready to skim the waves LOL
 
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