please help MERC people

[BASSNSNOW]

i have a 99 merc 115 on a 17 foot nitro i have absolutely no zip zero hole shot. when i give it full thottle and my motor will load up like crazy it will rev at 2000 sometimes for **** near 2 minutes but sometimes it will only take 30 seconds but it loads up none the less. my top end is ok at 54 mph at 4200 rpm but it takes forever to get there. i brought it to the shop for intermitent stalling from neutral to gear they replaced the acelerator pump a few fuel lines but since then the lag appeared acceleration was fine prior. i brought it back they checked the compression and it was 118, 120, 120, 124 it also has a good strong spark. i am completely frusterated and irritated, someone give me and explaination PLEASE- thanks

 

[kevlar3000]

Re: please help MERC people

Could you be over propped? I don't know about the new Mercs but with an old 115 you should be getting 5500 rpms wot. Just a hunch... I know it can drive one crazy!!<br /><br />Good luck

 

[Fouled Plug]

Re: please help MERC people

Sure sounds prop-related. What is the diameter and pitch of your current prop?

 

[BASSNSNOW]

Re: please help MERC people

i have a 26 pitch laser2 prop that came stock with the boat. the only reason i'm not that sure it's a prop problem is that i was able to get to 5000 rpm and 58mph prior to the work done on my motor

 

[kenthrussell]

Re: please help MERC people

did they do any work on the carbs??? check with boat out of water and not running when you give it wide open throttle are the carbs the butterfly valves actually wide open?possibly they didn't sync the carbs right if this is the problem let me know and i can tell you how to do it...not hard and no special tools required about 15 minutes

 

[kevlar3000]

Re: please help MERC people

I agree with the carb check as fuel delivery may be the root of your problems, and I would also find out your wot recomendatations, that sounds like a lot of prop. It may be that a 24 pitch would put you in your most efficient powerband. It will increase holeshot and maintain the top end you desire. You don't want to load the engine with a prop it can't efficiently turn.

 

[BASSNSNOW]

Re: please help MERC people

thanx for all your replies according to the merc website my max rpm should be 5250 which was just a bit higher than what i was able to achieve before. i had to pass on a tourney today because my boat just won't run right and i dont want to damage anything. i cant even bring it to the shop for three weeks they're all booked up (different shop)

 

[kevlar3000]

Re: please help MERC people

What a drag!! The wait takes forever!! Your rpm is not too far off, so it sounds like you are in the right area @ 5000 If you knocked down to a 25 that would give you a couple hundred rpm. Does that Laser have vent holes in it? Not related to your fuel issues, but it should give you a good hole shot once all is fixed. There are some shops that are so booked in advance that thay simply don't take the time to really get your motor right as they are TOO busy. It is a shame as it costs us money and time.

 

[BASSNSNOW]

Re: please help MERC people

yup my laser 2 prop has vent holes. i cant wait to see what this motor can do. from the time that i got it, it ran somewhat shakey so i brought it in for a tune and to solve the intermittent stalling. since i got it back it runs 10X worse. i'm going to look into the carb ajustments and prop pitch with a NEW shop thanks guys