boat wont plane out

[tuff luck]

I have a 1988 17FT cajun bass boat with a 1988 90 hp mercury oil injected outboard. Ireceived the boat not running. I put a new switchbox on the motor and then had the required spark that i needed but since the boat sat around for about three years the carbs were gummed up.I rebuilt the carbs and flushed the fuel tank replaced the filter and rebuilt the fuel pump. put the boat in the water and it went with a little bit of hesitation and it took awile to get up on plane but it ran 53mph.I then took it home.two weeks later went to take boat out and could not get up on plane no way. it's very dead as if it were dragging an anchor I watch the rpm and it only gets to about 2800 rpm but when out of the water it spins as much as you want if you know what I meen some times it goes some times it dont please help have to young boys that would like to go fishing.

 

[greasemonkeyozi]

Re: boat wont plane out

Make sure your jets are set right. Sounds like your running a little lean. On your carborators, turn your idler screws clockwise all the way, dont tighten them, just snugem. Then rotate them counterclockwise 2 full rotations. Now your jets are set to a good start. <br /> Go to your local dealer parts guy and buy a can of mercury power tune. Spray some in each carb while motors running to clean those things out.<br /> My guess is your fuel system gummed up in time and its trying to clean itself out. That gumminess may have clogged something in your carbs. If power tune dont get it, may have to take your carbs off again and clean em out with a fine tooth comb.<br /> If any problems, email me at greasemonkeyozi@yahoo.com.

 

[tuff luck]

Re: boat wont plane out

I triying to get a few ideas so that when I go to work on the boat this weekend I can do all that i can do please give more options thanks and to mercury.grease.rag I tried to email but no reply email from damangary@bellsouth.net your the only one that replied and I thank you would like to pick your brain a little further

 

[The Marine Doctor]

Re: boat wont plane out

Check compression and spark. You may have dropped a cyl.<br /><br />TMD

 

[jim dozier]

Re: boat wont plane out

Just how exactly did you rebuild the carbs. If after following the marine doctors advice you find that all cylinders have spark, take another look at your carbs. You wouldn't be the first to inadequately clean your carbs (complete dismantling, cleaning, compressed air, replace and adjust with rebuild kit parts). You might try squirting some premix in the carb throats, if it picks up, you ar running lean and it is most likely the carbs. I respectfully disagree with mercury.grease.rag and suggest that spraying carb cleaner in the carbs will only spend your money. Buy a beer instead and drink it while you ponder the situation. When you did the carbs did you also do the fuel pump? If not you may want to look there also. Also if the motor was sitting up long you should replace the water pump impeller as they have a shelf life used or not.

 

[tuff luck]

Re: boat wont plane out

to jimd yes the fuel pump was rebuilt and the fuel filter replaced at the time of rebuild the fuel tank was also cleaned completly with new filter I used mercury rebuild kit and carbs were soaked for about an hour and blown threw to get every thing out i did the best job i could do with out knowing that much about two stroke motorI dont know how to adjust the carbs or where or if its possible

 

[KCLOST]

Re: boat wont plane out

tuffluck,<br /><br />Don't over-rev the engine when using your ear muffs in the driveway.. Take it easy, as you could damage the engine by not getting enough water to it at higher rpms... Go 1500 max for any extended period of time...<br /><br />Anyway, Did you have the kids in the boat the second time out? Or was there any signifigant added weight at the back of the boat to hinder hole shot? <br />Do you have your motor trimmed all the way down when you rev up? 53 mph with your set-up seems excellent... I just wonder if your trim setting or even prop selection may be a cause to hinder your start up...<br /><br />What was your max rpm's when you reached 53 mph your first time out?

 

[jim dozier]

Re: boat wont plane out

I would refer you back to the marine doctors advice. Check to see if you are dropping a cylinder. It could be spark or it could be lack of fuel due to an incorrectly set float valve in the carb. First idendify the dead cylinder and go from there.

 

[tuff luck]

Re: boat wont plane out

to KCLOST I dont over rev I just push throttel forward real quick and pull back real quick.The reason for that is just to see if it would rev. The second time out I had less Weight in the boat. When the rpm gets up to about 3300 rpm the boat will start to plane out and the rpm rise rapidly after that point then I trim up the motor rpm will rise a little more I really dont know what rpm is at cruising speed (53mph)I have also tried two props one is a laser2 with exhaust outlets on the back side of the prop and also the front supposed to help with whole shot launch .the second is the original prop for the motor.both do the same thing except one runs 53mph and the other runs 49mph.I thank you all for the advice Im sure I'll get it soon.keep it coming thanks