I am having trouble getting my mud motor to plane my boat out. I have a 29hp kawasaki engine on mudbuddy sport pushing a 16' xcel boat w/the pods on the rear. i just bought it and have carried it out twice with only me in the boat. I cannot get the motor to plane boat out and it'll only push boat about 10 mph. Once you get boat running at half throttle, when u squeeze throttle wide open the boat will not pick up anymore speed. You can feel the boat try to take on off but then it's like it goes back to slipping or something. I called mudbuddy and they told me that if my transom is 15" then shaft should measure 36" and if transom is 19"-21" then shaft should measure 48" from halfway at bottom of gear box to locknut on prop. Transom on my boat measures 17" and and shaft measured 27 1/2". Any idea of what may be causing boat not to plane out or if 10 mph is as fast as it should go.

No you should definitely do better than that, you should be pushing in the early/mid 20's. What are your rpm's when wide open?

Tack is reading from 3550-3600 rpm's when it is wide open.

What's the prop measure?

At widest point across it measures 12 1/4".

yeah its definitly not your prop,

Got a pic showing a view from the rear....

Or a side profile of where the lower shaft and prop
are in relation to the boat bottom....

Like I said, it feels like it wants to push on and take off, but then it goes back to bout half throttle speed with the throttle wide open. It actually reminds me of an older truck that trans fluid is low and will engage then quit. Only thing is prop spins and motor is running like a top.

I do not have any pics of that, but I looked at it when i got home the other day and it looked pretty well in line with bottom of boat. Motor has tilt/trim on it and it still does the same with motor trimmed all the way down.

hmmmm teeth on belt may bee worn down or your clutch is slipping, check your belt make sure its tight and make sure you have good teeth on it,

When you are running wide open - how much prop is showing or "surfacing" ???

Can you trim down at wide open till entire prop is submerged ???

What rpm's are you getting?

3550 to 3600 is what i read

I am wondering if he has a transom height mismatch or if transom angle
is keeping it from trimming down enough to get a good "bite"...

If he had a clutch or belt issue - it seems like it would show up when
he launched out of the hole - but he is describing a problem right
when the hull is about to transition into planing out.....

A good picture would sure help....

Forgive my ignorance, I'm assuming it has a clutch being as it has a neutral and u can also bump toggle switch to engage prop then disengages. The boat really doesn't just blow out of the hole like I would've thought it would have either. I'll try to get pic on here or if someone has e-mail i can e-mail one.

I talked to mudbuddy yesterday about transom height and shaft length and what they give me was not anything mine measures. They told me that 15" transon should have 36" shaft and 19"-21" transom should have 48" shaft. My transom is 17" and shaft measured 27 1/2".????????????????????????????????????????????????

If you trim down all the way - where is the center of the prop
in relation to the boat bottom ???

It looks to me that when it is trimmed all the way down, the motor should be pushing nose of boat in water, but butt end of boat sits in water and will not plane out. I have tried every position of motor trimmed up to down and get same result. I can't figure out why motor is hitting rev limiter but it is running same speed as when u have throttle half open.

your motor to transom height is not adding up

I just re-read your original post. You said you have a sport model frame? Is that correct?

If so, it was never offered with a 36" or 48" drive.

Can't tell from this picture - cause motor is raised....

But I think something is wrong with transom height or angle....

If it is just the angle, you can buy or fabricate a wedge shaped shim
which is thicker at the top, that will let motor trim down deeper and
get a better "bite"...

pic

Yes sport hd, the measurements is what mudbuddy give me.

float boxes starve prop of water creates cavitation Looks to me that your transom may be alittle to tall for that motor and therefore putting your motor at a bad angle for trimming it out to reach maximum speed

So the motor needs to set further down on transom?

So your outdrive is 27 1/2, when you trim all the way up the bottom of your belt housing should be just over 1-2 inches above the bottom of your boat. Keep in mind thats trimmed all the way up

Those are the correct measurements for a hyperdrive, not a sport. Somebody screwed up.


As far as the pic goes, that is defintely a short transom hyper sport motor, and it looks like the correct transom height. The angle is impossible to tell from the pic, but I will say that I have never seen an excel with pods, and I dont know if I have ever seen a boat with a surface drive with pods that large. When were they added (before or after you put the motor on this boat)?

If you can - go out and trim it all the way down....

If you can't get your entire prop down below the hull
then a motor wedge might be the "quick fix" - it should
be thick enough at the top to get that prop down below
the hull bottom....

Sounds like this MM and hull were just "paired up" and
may not be rigged quite right yet....

INteresting for sure....SUBSCRIBED

Yet, meaning it can be done and I'm not gonna have to sell?

I believe the prop is gonna be below the hull trimmed all the way down. "Being as it is", what then would I need to look at as the possible problem?

Turn key on engage clutch and see if you can spin the prop by hand! should have alot of resistance and only turn over on the motor compression, but if you can turn the shaft without turning the motor over you have anouther problem

If all is running properly, what kind of rpm should it run?

I would think 38 or 3900, but not sure about a 29 hp...

Were the pods on the boat from the factory?

Yes, they were not added afterward. Any idea what would be causing it?

This one has me stumped.

It should be plaining at those RPM's.. Is it bumping the governor or can it not turn up anymore? What are your RPM's without a load in neutral?

I have heard of some clutches that were defective or slipping, can you feel any jumping or bursts of power at the prop at any time?