Poor running 1990 GT-150...

[bassinman215]

I'm having some trouble with the 1990 GT-150 on my 1990 Champion. I do not have model or serial number off hand but will post them when I get home from work.

The motor will idle well on a hose, but will not idle in the water without holding the gas down. The boat has trouble getting on plane, and when I step on the gas, the motor either dies or will rev to about 2000 rpm and hang. When it gets to 2000 rpm, I have to trim it up to increase the revs, and once it gets over 2300 rpm, it will spin up and will get on plane.

The fuel bulb often needs to be pumped. I have replaced the fuel line from the motor to the gas tank and it hasn't helped. Also, pressing the choke does not immediately cause the motor to "wake up."

My mechanic (who is currently 250 miles away) suggested that the motor is either missing on a cylinder (which seems unlikely given my experience with V-6 and V-8 Chevys that have had loose or crossed wires) or that the intermediate jets on my carbs are clogged.

Any suggestions?

THanks!

[316jughead]

Check for spark all cyl. If you have good spark check compression. I assume you did a visual check of carb linkage and roller.

[bassinman215]

What's a good way to check spark? Can I stick a screwdriver in a plug wire, ground it to the block, and crank it over to check?

I need to get a compression tester. Test it hot or cold?

The carb linkage all looks to be fine. Everything is opening when I step on the gas, and the timing roller is progressing forward.

THanks

[DIXIEDOG]

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bassinman215 &raquo;</TD></TR><TR><TD CLASS="quote">What's a good way to check spark? Can I stick a screwdriver in a plug wire, ground it to the block, and crank it over to check?

I need to get a compression tester. Test it hot or cold?

The carb linkage all looks to be fine. Everything is opening when I step on the gas, and the timing roller is progressing forward.

THanks

</TD></TR></TABLE>


To check for spark use a spark tester and set the gap to 7/16" and turn it over looking for good spark.

It could also be dirty carbs causing your problems as well

[Sportwin]

While idling on a flush kit try removing the plug wires one at a time to see if each cylinder is operating properly. You will be able to hear the spark jumping when you get the plug boot partially off and when you pull it away the cyl should stop running and then start again when you replace the boot on the plug. Use insulated pliers to prevent the shock of your life. If all are operating remove the air silencer cover while in the water. Have someone else operate the engine and when they accelerate use an oil squirt can filled with fuel to shoot fuel in each cylinder one at a time. If the engine speeds up when fuel is squirted in a particular cyl that indicates a fuel restriction in that carb. A cylinder that is operating properly will cut-back when fuel is added. Good luck.