1984 Suzuki DT50 - slow speeds

completetech

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Jul 7, 2012
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I recently brought my 1984 Suzuki DT50 in to have the motor looked at by a mechanic as I was originally having some serious speed problems with the motor seeming to somewhat bog down anything over slightly above idle speed.

He replaced plugs, completely rebuilt carbs 5 or 6 times ( long story, not sure he knew what he was doing) and the motor does fire up and run a bit better then what it was, but not much better.

It seems to me that with this motor on a Sport-Craft Fisherman 170 SS at Wide Open Throttle I should be going faster then 10-12 MPH ( gps based). But the mechanic states that there is no way and I need a bigger motor. Which seems crazy to me.

So with all that stated. I guess I'm looking for some suggestions as to what would cause this to run so slow and seem like it's working so hard at 10 MPH. I can just not believe that this motor only goes 10 mph on a small 17ft boat.

As a side note. The air silencer is missing and we had to rig up something to act as the air silencer as it seemed as though it was sucking way to much air originally.
 

99yam40

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Sep 7, 2008
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motor needs good compression,
good strong spark at the correct time(timing)
these are all easy to test.
if those are all good and in spec, then you look at fuel to air ratio.
too much fuel just like too little means the cylinder is not going to burn it properly and produce power as it should.
every cylinder has to be doing it's job or it just drags down the others.

now we have no idea what that boat weighs or what it is rated for(HP) wise.
maybe it is under powered, but you have not given enough info for us to even guess
we also have no idea what the RPM is doing at WOT on your rig or what prop you are using
 

completetech

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Jul 7, 2012
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Sorry. I thought I listed everything above. According to the factory tag on the boat it is able to use anything from 40-110HP. The boat it is on is a center console Sprot-Craft Fisherman 170 SS.

As far as WOT RPM. I do not have an rpm gauge. But I will attach a video showing what it's doing.
 

99yam40

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not many people will have accounts there to even look

a boat rated for 110hp is not going to do well with a 50

people on here need to know what prop and RPM it is running at WOT to help any
 

completetech

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Jul 7, 2012
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As stated...

The factory tag states that it an run a 20HP - 110HP.

As far as having the account. You don't need an account to view the video I posted. The video will not post directly here.
 

Mohawkmtrs

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Jan 13, 2010
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" You don't need an account to view the video I posted."

I just went there and it's asking for my account.
 

99yam40

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It asks me to sign in so that looks like I need an account to be able to sign in
 
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