My motor idles just fine and revs to 4200 rpm on land. The second i put it in the water and go to take off it wont get up it just puts around at 1500 rpm. It wont die out or anything just wont go anywhere. I have a 32 prodrive. I have had a new carb put on it and fuel pump. Also a new water seperator and fuel pump. Everything was fine then i had to replace a coil on it and it was ok now it wont run worth a sht and i need it sunday. Any ideas would be helpful thanks ahead of time..

Sounds like you are running on 1 cylinder. Do you have good spark on both? If not check the coils and make sure a wire didn't come off. If all checks out do a compression and leak down test to see if you may have a bent valve. Just some places to start looking. Heck first thing is make sure your plug wires are pluged on good and the spark plugs are gapped correctly.

X2 compression test can rule out alot real quick!!

Check your diodes. If you replaced a coil, it's possible the diodes could be fried making it run on one cylinder.

Ill bet its a one cylinder issue

An easy check....... Pull one spark boot, replace it, then pull the other. If it kills with only one plug then you know you are only runnin on one cylinder. Pull the valve cover, if everything looks good there then check your diodes.

Def sounds liek a one cylinder... Do what QC said and make your assumption there. Should be an easy diagnosis.

I have good spark on bother cylinders. Ok i will try that when i get home ill pull the boots. Off one by one. If that is the case wouldnt it run like shit even with out a load because it idels good and runs wide open at 4100 rpms no problem. How do i check the diode????? The plugs are gapped coreectly and have spark at plug wire. How much compression should i have on this motor? Thank you all so much for your help. I live in central illinois and the closesnt dealer is about 2 hours away or i would just take it to them.. Thanks again

If you have spark on both cylinders your coils are firing. Pull the boots off the plugs one cylinder at a time and you will see if the opposing cylinder will keep the engine running. If you find a cylinder with problems pull the valve cover to make sure a push rid didnt come out of the rocker arm.

Maxiss thank you so much for your help.. The push rod did come out of the rocker arm and the bolt that hold the rod in place was laying on the bottom. I guess my next question is what caused this and what do i do now. I am very thankful for your help and i will gladley send you some money for helping me out i dont exspect anything free i just am so far away from the dealer and am hoping to use it sunday. Please let me know what to do next you can give me a call if you want and i will get your address and get a cashier check sent to you.. 309 258 6452 thank you very much

bro thats what this site is for right there. helping guys that need it i a hurry. i'm sure he dont expect any monitary donation for his wisdom. I might be wrong, but i couldnt take money from ya for helping like this. glad ya got it figured out and hopefully get it ready soon.

i know but i dont like repaying people. So id gladley pay him or take him hunting. I would be paying a place to do it anyways if they were anywhere close to me. I just hope i can get her fixed im worried its something major i just got the motor..

Id suggest polling that push rod out. Roll it on a flat surface to make sure it isn't bent. Likely its fine and you just need to adjust the valves but better safe than sorry.

Shit happens at 4000 RPM's

I would just get a new set of pushrods and reset the valves... Out of curiosity which valve was it?

Bro I dont expect you to send me a damn thing. Hell I'm happy that my post and the posts before me were able to get you to save some cash and you fix your motor yourself. You see this site might get rough and rowdy at times, But rest assured if there is a problem were gonna help you.

Also to fix the issue.
well you see ther is a rocker arm bolt and there is your valve adjusting bolt with a jam nut. Regardless of which one it is I am sure you can see how it goes together by looking at the other valve. Once you get it back together, set your valves with the piston at 1/4" past top Dead center and set your valves @ .004"-.006" and then button her back up.

When adjusting valves make sure you fully understand what it means to do so on the "compression stroke".

i checked everything nothing was bent. I went yesterday and bought a book for that motor. Told me set it at .005 and i did so. I got her all put back together and even took her out at 11:00 last night. Ran like a champ. I appreciate all of your help and if you guys are ever in illinois get ahold of me i have some killer spots. Not only did you save me money but i will be able to take the kids i promised on the youth hunt this weekend.. Thanks much again

Good luck with your hunt!

Glad to know you're back up and runnin.