Baffled by 80 Horse

I've got an 83 Blue Band 80. The motor was rebuilt but still won't run consistently. I checked the compression on all 4 cylinders,they were within 5lbs of each other. I checked the spark with a spark tester and all 4 had great spark. I took the carbs off and checked to make sure that no float pins and needles were sticking, they all went up with the floats and fell when I let off on the floats with no sticking. I checked the fuel lines to see if everything was clear and they were clear of any obstructions. I pulled the little fuel filter cover off and the screen was clear but I shot carb cleaner in the screen and blew it out with air and it is clear. I left the cover off and pumped the bulb and fuel went everywhere, so I am assuming that the motor is getting good fuel. I ran the boat yesterday with everything buttoned up and she would come off the trailer fine. Put in forward gear and it fell flat on its face. I re-trailered and came home. I checked everything again last night. ( compression, spark, fuel out of the lines) Put it back in the water this morning without the cowling and carb cover on and after warming up she ran good. I ran it for about 4 seconds turning 4500 and kicked it back to to 3500 and fuel was spitting into the carbs. I kicked it down in to a troll speed and it did good. I shut her down and killed a little time hitting a few crappie beds and decided to try it again. It was a hard start ( 3-4 times) finally got it started and tried to head out at 1800 rpm's, she fell on her face. Choked the hell out of it with the electric choke off the controls and ran it up to a very fast idle and then jammed it in forward and it took off like a rocket. Trimmed it down and brought it back to 3500 and it ran fine. Brought it back to a fast troll to prepare for re- trailering and it did good. I feel like it is something relatively minor but I am at my wits end. The rope at the end of my rope is getting smaller by the minute and I cannot hang on much longer. From this post can anyone tell me what may be the problem. I am close to calling it quits on this motor , but the only thing that keeps me from doing it is no extra money for a new motor and two boys that love to fish. I would appreciate any help with the motor.

Re: Baffled by 80 Horse

have you tried a linc n sinc?

http://www.iboats.com/bbboard/bbBoard.cgi?a=viewthread;fid=29;gtid=891893

Re: Baffled by 80 Horse

No sir I have not. Can you walk me through the process?

Re: Baffled by 80 Horse

Sounds like a fuel problem as if it were ign choking and etc would not help here are some thing to ck- If a built in tank ck the anti syphon valve-apparent fuel line and bulb problems, if you have a differant tank and line available run them-have you rebult the fuel pump and cked the pump valves-some center bowl carbs have a trash screen under the inler elbows-change the inlet needles and ck float height-make sure the plastic venturi is in both carbs-clean the high speed jets-seal the carb soft plugs-the other day you ask about the nylon roller on the top carb linkage it is a actuator arm the roller is NSS and I don't have a bleed line route in my manual sorry--Bob

Re: Baffled by 80 Horse

I agree that it appears to be a fuel problem -- probably a weak fuel pump. As for Link & sync, it is not something you "walk through". If you are going to work on this engine you need a service manual specific to it. It can be obtained on-line at the Mercury Parts Express web site. You need the serial number of your engine to get the correct manual.

Re: Baffled by 80 Horse

I've checked Mercury Parts Express and the service manual that is specific to this motor is No Longer Available. I can get a Seloc that covers multiple motors but not one specific to this motor. I have tried pushing in the choke when she starts to fall on her face and the motor picks back up and runs? The serial number is 6234592. Also parts express shows that the fuel pump is NLA, so if the fuel pump happens to be the culprit what can I do?

Re: Baffled by 80 Horse

Buy one here or NAPA number 18-7808 for the kit and Mercury number is 21-30430 A13 ussualy if choking helps its the carbs and if you pump the bulb and it helps it's the fuel pump