80 Red Band Merc no RPM's

[^Fire_N_Ice^]

Hi<br /><br />Im reasonably new to having to repair my own boat, I bought a boat and dropped in the water yesterday to find I have I hope a minor problem. Motor starts fine and seems to run fine however when I went to power off I had no power ! When I put the throttle forward I have minimal power however if I push the trottle as far forward with a bit of weight I seem to get more power but still very little. Can someone tell me does this seem as simple as just a stretched accelerator cable maybe ? The wash behind the motor looks powerfull enough just doesn't push me forward. The forward push would be equal to maybe a 3.5 hp push.

 

[^Fire_N_Ice^]

Re: 80 Red Band Merc no RPM's

Sorry can anyone also tell me the year model s/n is 3060508 Thunderbolt 80 hp Red Band Merc. Now I know this a really blonde question but to make sure this is a 4 cyl and this should be running on 2 stroke fuel ? Correct ?<br /><br />Thanks for your help

 

[steelespike]

Re: 80 Red Band Merc no RPM's

I believe your motor is a 71 4 cylinder.<br /> It is 2cycle and uses a 50:1 mix.<br /> Look in the carbs and see if the butterflies are opening all the way at wot.<br /> Then you need to determine if the motor is sound.<br /> Check the compression should be at least 100 lbs. and vary no more than 10% cylinder to cylinder.You need to check for spark.But get a manual and follow the correct procedure or you may damage the ignition system.<br />Aftermarket manuals are available at the bottom of the page among many other places.<br /> Getting it to australia may be tough.<br /> You could try ebay.<br /> If the motor checks out go through the fuel system from tank to carbs clean and repair as required.Dont forget to check the tank vent.<br />While your at it if you dont know its history<br /> replace the impeller.

 

[^Fire_N_Ice^]

Re: 80 Red Band Merc no RPM's

Thanks Spike <br /><br />The motor checks out to be fine however someone else has suggested a slipping prop, so think I will take it to a merc dealer and see what they say I'd reckon.<br /><br />Thanks again

 

[^Fire_N_Ice^]

Re: 80 Red Band Merc no RPM's

Ok Spike can you answer something else for me ?<br /><br />Let me try to explain this as best as I can.<br /><br />There are two levers on the forward controls, one is the throttle to go forward neutral and reverse, the other is I guess for when your running your engine out of water and when the engine is cold, I hope you understand so far. If I push my t-bar throttle forward I get now power or minimal power ok we've established that, however the other flat lever, once the motor is warm I push that to the closed position and the motor stalls. this sounds like lack of fuel to me, do you think that maybe my whole problem may be as simple as I was so stupid that I may have had the fuel tank vent completely closed ? I didn't check it on the water yesterday as it was the hubby who put the fuel in the tank. Maybe something like a closed vent would not give me power as it is starving for fuel ?