runs good,no power under load

[toomanyboats]

I have a pair of 1100 1965 Mercs on a 30 foot pontoon boat i just finished,the problem is that one of the motors runs real bad by its self,it starts right up cold,starts every time,revs real good in neurtal,very strong motor,no smoke,no bad sounds,put it in gear and it idles great,low end is fine,give it throttle and it has no power and falls on its face,,?add the other motor (it runs perfect)and it runs better as were going along,but still seems to not getting the rpm's needed for peek performance,I'm good with motors and i am puzzled?this motor should run as strong as the other by its self.<br />Any help and thoughts will be needed here.<br />Thanks

 

[The Marine Doctor]

Re: runs good,no power under load

Check the fuel connections.<br /><br />TMD

 

[DJ]

Re: runs good,no power under load

toomany,<br /><br />The pintle type fuel connections on older Merc's are notorious for developing air leaks.<br /><br />There is an O'ring in the female receptacle on the engine side. Check that.

 

[toomanyboats]

Re: runs good,no power under load

I changed the fuel connection to the other gas tank for the good running motor,and the thing runs the same ,so its not that,any other ideas

 

[greasemonkeyozi]

Re: runs good,no power under load

My motor had somewhat the same problem. The manufacturers use zip ties for hose clamps on all hose connections instead of real hose clamps. Why, I dont know. Go to the parts store and buy some metal screw type hose clamps and replace those zip ties if not done so. If this does not fix your motor, consider rebuilding fuel pump and carbs. Do your fuel pump first since its the easiest job. $5.00 for a diaphram kit for fuel pump at your dealership. Good luck.

 

[greasemonkeyozi]

Re: runs good,no power under load

oh yeah, the marine doctor reminded me of something that can pertain to this problem. Go to your local NAPA store and buy some SEA FOAM DEEP CREEP. Spray some in your carborators while motors running in short squirts for about 5-10 minutes. Do this be4 you consider rebuilding your carbs.