Questions, should there be a screw there? Should I lower my motor? With pics.

[Suctoes]

I've got a 2000, LTPTO 40, 2 cyl, 2 stroke and it won't run above 3800 rpm @ WOT.

1, Looking from the rear I think my motor needs to be lower in the water. it came off a pontoon boat. And is now mounted in the middle mounting holes. Should I drop it to the lowest holes? (pic-1)

2, After looking to see how hard the carb would be to remove for cleaning, I noticed what looks like an ajustment screw missing. Should there be one next to the other brass adjusting screw? (pic-2)

 

[usskydvr]

Re: Questions, should there be a screw there? Should I lower my motor? With pics.

Your height look about right ( you have a good size step at the transom).
Your trim looks off as the anti-cavitation plate should be parallel with the bottom. ( or a bit angled up at speed) Yours looks to be trimmed in. ( that would push the bow down into the water)

the carb hole is a vent. no screw. The one next to it is the idle mixture screw. (brass)

 

[mercfixer]

Re: Questions, should there be a screw there? Should I lower my motor? With pics.

No there should not be a screw there, merc started that crap on the 4 cylinder motors for a nomber of reasons, one was cleaning up for our beloved government. This same style carb and condition can be seen on the lower two carbs of the four cylinder 2 strokes. Little confusing after dis-assemble for service if you are not familiar with them. The rule of thumb on motor mounting is that the wide finned part of the gearcase refered to as the cavitation plate should be even with the bottom of the hull. Too high and you will cavitate, which you have most likely experienced, too low and the bow will porpoise up and down.
Hope this helps....

 

[ufm82]

Re: Questions, should there be a screw there? Should I lower my motor? With pics.

A couple things here.
1) The anti-ventilation plate should be 1"-1/2" ABOVE the bottom of the keel. If it is lower then it will drag in the water at any speed and rob you of speed. Remember, the water coming from under the boat goes "up" as it moves back and you want it pushing on the bottom of that plate. While your picture shows a little paralax, it looks OK. DO NOT lower it. That will only cost you speed. In fact, if you level the boat and put the plate level and it isn't that high, you will want to RAISE the engine.

2) If you can only get to 3600 (assuming the engine runs normally) you need to determine what pitch/type of prop you have. If it came off a pontoon it may have a prop designed for a pontoon. That is, a high-thrust prop that helps push a pontoon but keeps you from hitting you WOT. That looks like a big blade prop to me and the one blade looks damaged although it may just be the contrast from the grass.

UFM82

 

[Wingedwheel]

Re: Questions, should there be a screw there? Should I lower my motor? With pics.

I agree about the prop possibly being set-up for a pontoon. Do you know the pitch?

 

[Dave1027]

Re: Questions, should there be a screw there? Should I lower my motor? With pics.

No there should not be a screw there, merc started that crap on the 4 cylinder motors for a nomber of reasons, one was cleaning up for our beloved government.

Huh? Care to elaborate on that? What does the gov got to do with it?

 

[chum1]

Re: Questions, should there be a screw there? Should I lower my motor? With pics.

Huh? Care to elaborate on that? What does the gov got to do with it?

I'll elaborate, just turn on the news and watch the elected prez and the current gov clean and spend this country right into the stone ages.......oh wait was that boat related.