WOT Issues

I am running a 14'x48" Lowe aluminum flatboat with 1999 25hp Johnson. I have added an extended front deck (aluminum), trolling motor and battery, and 2 "bass boat" style seats. Other than that just the usual ice chest, paddle, etc. I know the boat is not really streamlined nor light, but I am not getting the speed or rpm's I have previously.

History- sat up for a while and would not get to full throttle. Cleaned carb, no change. Put in shop, replaced fuel pump, head gsket and re-cleaned carb. Idles and runs properly, just not getting to WOT rps. Or so I believe.

Never was real fast boat, but now I can feel it straining. What can I do? It used to run better with the same gear. What can I try before I have to consider swapping out for a larger engine.

Thanks for all of your help, even though I'm new to this forum.

Re: WOT Issues

What are your compression numbers? If your shop changed the head gasket I'm assuming they weren't very good.

Re: WOT Issues

I did not get a number from the shop. I was told that the numbers were good, but they weren't even and that's why they changed the gasket. I understand that is counterintuitive, but it has been changed and should be ok now.

Re: WOT Issues

Bump. Come on guys I know yall have some ideas.

Re: WOT Issues

did you remove and clean the highspeed jets. would also suggest a link N sinc.

Re: WOT Issues

You added weight to the frount, sounds like its plowing, try triming the moter with the stop rod. raise to higher hole.

Re: WOT Issues

I would agree with the plowing, except for the fact that the bow is in the air because it won't completely plane off. It seems to do be lacking power. I am ssuming all is well with fuel since I got it back from the shop and they replaced the fuel pump. The only thing they didnt do is link and sync. I am gonna attempt it this weekend. I was just hoping it would be something a little easier to attempt before going through the link and sync process.

Re: WOT Issues

I hope this response helps, I had the same issue after workig on a boat, ran great, not very fast but would plane, did some additions and could not plane. I had to reprop for the extra weight. if possible to get a less pitch prop, usually one pitch or two smaller, should let your rpm's go up and get you on plane, this is as long as your motor is o.k., or try removing the additions and see if you can plane, if you can, the weight and prop could be the issue.

Hope this helps