I'm new to the mud motor world and need help with the lack/loss of speed from my boat. Here are the specifics:

- Boat is a 2010, 17'x60" custom made boat from Prodrive
- Motor is a 2010, 36 PD w/ hydraulic FPR
- Original speed of boat when purchased w/ 3 men in the boat was 23-24mph and 25-26mph with 1 man
- Motor now has 52 hours on it and I noticed a drastic loss of speed at around 36 hours
- Present speeds are 17-18 mph w/ 3 men and 21-22 mph with 1 man
- RPM's are presently around 3650-3725 with 3 men running in water and 4100 RPM out of water in nuetral

I called Prodrive when this originally happened and adjusted the governor, but that did not fix the problem. (By the way the guys at Prodrive have been great throughout the entire process.) I'm from Central Florida and run mainly in weeds, hydrilla, etc. and not much sand/mud. I have not measured my prop yet, but I'm not so sure this is the problem since it happened so soon (36 hrs.)and sudden??? I purchased the boat last fall and I'm coming up on the warranty running out and do not know what to do? I'm also open to having the motor altered for more speed once the warranty runs out, but I have NO IDEA who to take it to? What do you guys think it is or recommend? Also, do you know of anyone in my area to take it to? I really want to get back to the original speeds before duck season rolls around. HELP!!!Pictures from iphone 091.jpg

What shape is you prop and hull bottom in? RPMs sound good but you probably bump them up another 100-150. That won't give you 6 or so mph back tthough.

First couple things. What kind of shape is your hull in? Any hooks, or big indentations especially near the transom area? Check you're prop diameter. If you hit any sand, you could burn your prop up that quick easily. Although you would probably be noticing a lot higher rpm's if your prop was worn down enough to lose that kind of speed.

Check those simple things first and get back to us. Next things I would check would be to make sure both cylinders are firing. Make sure you're getting good fuel. No air in the hoses. Then check valves. Is the motor running okay? Making any noises? Bogging down? More info you give us the better.

Steve,
If your still under warranty, take the engine to a local Briggs shop and have them look it over for maintance. If there's something up, it should be covered under warranty.

I have a 2007 PD and I notice lower speeds with a worn prop and weight positions in the boat. I would look at getting a new prop first then take it to a briggs dealer.

One last thing...Kp hooked me up with an external fuel pump and that seemed to help too.

4 far as mods, check out Sid (fast duck motors) he is central florida mudbuddy guy. He works on all motors and is a terrific guy. He is very honest And will shoot you straight.

Also check out "united waterfowlers of florida". Lots of great people!

Cb5331, thanks for the reply. I don't seem to have any hooks underneath the boat, but will look more closely tomorrow. I will also measure the prop and see if it has worn down any. The engine seems to sound fine and both cylinders are firing. It does seem to bog down more now than it did and takes much longer to get going. I'll also check the gas line and see if there are any problems there. Thanks again for the help.

DD, thanks also for the input. I did not know about Sid, but will certainly check with him on what to do to get a little bit more out of my engine. I don't want to over do it. Do you think he can help me troubleshoot my problem? i'll check with KP on the external fuel pump and see what he thinks as well. Thanks again!!!

If its bogging down, and seems to not have much power, you may have been had by bad gas. Water in the tank. Hole in your fuel line somewhere. Are you using quick connects? If so get rid of them. What else is in line on the fuel hose?

Dont know but I like that hull....

What's ya compression Lookn' like?

CB, I checked the bottom of the boat this morning and it had no hooks anywhere that I could see. I also checked my prop and it measures 12 1/2" from tip to tip. The width of each blade is about 4 3/8" wide. What is it suppossed to be? I've used Sea Foam in the gas back when this first happened thinking that I had bad gas too, but that did not help any. I do not have any quick connects on the gas line and nothing else is in line on it. I did not have time to check the entire gas line, but will try and do that this weekend.

Schrieverboy, I have not checked the compression yet, but will try and do that as well.

poker, Thanks...Pictures from iphone 055.jpg

Stock prop comes 12 3/8 so you are fine there..

But FYI- you get in some of that Florida sand and you can wear that prop down quick... Easily in 36 hours.....

Are you sure both cylinders are firing?
Make sure your choke is all the way off...
Ck your compression if you can..
Shouldn't be the problem so soon, but ck your air filter and your fuel filter.... and if you got some trashy gas and then ran sea foam thru might have clogged up your filter..
Have you done any mods? Changed anything on it at all from before problem and after?
Is problem starting immediately when you leave dock or does it "kick in" after some time?
Making any sounds that are different?
What were your RPMS at WOT w/3 men BEFORE this started?

But sounds like a fuel or fuel delivery problem to me.. I would ck the whole system start to finish-you are getting fuel, just when you put it under a load and ask for a little more, it isn't getting there...

Post up a little more info and see if some of these guys who know a lot more than me can help you out. I don't know much about the CDI and what kind of problems you could have because of that...

Also, call KP back and see if they have any ideas. They know their stuff and are very helpful....

Caddobrook, Thanks for the advice. Both cylinders are for sure firing and from what everyone is saying it sounds like I really need to check my fuel line, pump and filter. The RPM's before the loss in speed was around 3800. I have not installed any mods to the motor or changed anything to this point. I also have not noticed any changes in the the way the motor sounds and the problem (lack of speed) happens as soon as I leave the dock.

I'm going to check the fuel system out this weekend and if that does not fix the problem, I'll call KP next week and see what he thinks it is. Thanks for all the help and advice!!!

weird....

your RPM's before were 3800 and now as high as 3725, but you have lost 6 miles an hour?

Have you played with weight distribution in the boat? That can make a HUGE difference in performance. Did you change your distribution around any from before problems to when they started? Added anything else? extra cooler? gas tank? trolling motor? battery? moved anything forward or back? side to side?

These boats and motors are VERY sensitive (much more so than an outboard and conventional type boat) to that and even moving someone/something from side to side can impact speed. Moving front to back can really impact it. Depends on each boat and motor combo as to what is best-you just have to play with it. I know on mine having someone sit on the middle bench facing forward or back makes a difference. And if you have several little things it adds up.... A loaded cooler shift from slightly off center to center can make a difference....

I pulled out of ramp one day and had two extra 5 gal gas cans in the front and my uncle up there and just couldn't get going right... moved cans to back and had uncle move back and picked up 5 mph just like that... then moved cans back a little farther and and picked up a little more.... got probably 6-7 mph total out of just shifting around and adjusting trim for that load....

Which brings up another question.. Have you played with your trim?

Good luck and let us know how it goes and what you find out...

Thanks caddobrook... I'm not real sure what the exact RPM's were before my speeds dropped, but I think they were somewhere in the 3800's???

The day this first happened, I had the same weights in the boat the day prior to this occurance with no problems... I had run with the same guys and gear on numerous occasions prior to this and had no noticible drops in speed. Ever since that day it happened, it has not run the same... I have even taken everything out of the boat and just had myself running it and still cannot get the speeds I had before.

I took it to Sid at Fast Duck Motors last weekend and he is going to troubleshoot everything for me and hopefully get it running better again. He seems like a very knowledgeable guy and we're looking in to adding some upgrades to the motor (new cam, carb, filter, and exhaust). Thanks for all of the input and advice...

check the choke make sure that is not stuck in any way because that sounds like whats happening. i left my choke on one time while i was running and i lost several hundred RPM's and quite a few MPH's.

it might also be your carb. might have some junk in the jets thats slowing down the fuel from getting into the cilinder.

hope you find out whats wrong, i know i hate whenever something goes wrong with my motor.

might also have water or trash in your gas. if you dont have a water-trap-filter i suggest getting one. good to have. gas tanks do sweat and the condensation gets in there and it will make your motor bogg and not run as good as normal. they are also cheap and easy to install.

do some cheap reeplacements like new fuel hose fittings new fuel filter new primer, things that won't hurt to change out anyway, what kind of fuel fittings you got? Do small eliminations before you tear real deeep into it.

Mudman350, I've checked the choke on a few occasions since this happened, and it seemed fine... I'll look into adding a water-trap-filter as well... Thanks...


Take'emgator, The fuel line is connected directly to the tank, so hopefully, that is not the problem... I'm sure it will be something simple and hopefully not have to go too deep to find the problem... Thanks...

did you do anything to it yet?

MM, it's at Sid's shop (Fast Duck Motors) and he is looking into it, as well as adding some mods... Thanks

I love boobie avatars!!!!

if water in your gas is not your problem i still suggest getting a fuel/water separator. very good to have in a boat.