115 tower of power carb issue

[Chris1956]

OK, First step in link and synch is to set the timing pointer correctly. Remove all spark plugs. Stick a dial indicator into the top cylinder. If you do not have a dial indicator, use a steel ruler or caliper. Set the piston to top dead center. Measure from water jacket cover to top of piston. Add .464 inches to that measurement. Turn the motor CCW 1/2 turn. Stick ruler into cylinder to sum of measurement. Turn flywheel CW until it hits ruler. Now piston is .464 inches before TDC. Set timing pointer to agree.

Now install top spark plug, and attach plug wire. Stick other plugs into their wires and tape the bases together and ground the bases to the block. Advance throttle until the carbs are ready to open, but still closed. Attach timing light to top plug wire. Crank motor and observe timing. It should be 2-9* ATDC. Adjust the primary pickup screw (on the throttle arm, just above the pivot point) to make the pickup timing correct. Note: you may need to adjust the idle stop screw (bottom most screw on throttle arm) and the throttle cable barrel nut to make this happen.

Next advance the throttle all the way and crank motor to find timing. Max spark advance should be 21* BTDC. Adjust the max spark advance screw (top most screw on throttle arm) to make it correct. Adjust throttle stop screw to stop the throttle open before it hits carbs stop. Throttle stop screw is below pivot of throttle arm, on the block to the left of the throttle arm.

That is it....

 

[justin27]

Sounds kind of tricky is that something that would be expensive at a boat mechanic to do I hate to get it all out of wack

 

[racerone]

Sorry, but " in gear on the muffs " is still the same as nuetral as the prop does not have to do any work.---Test compression and check for good spark on all 6 leads.---Good spark is spark that will jump a gap of 3/8 " or better.

 

[justin27]

It has good spark and compression I'm thinking that Mabye over time it wore through that rubber piece on end of timing screw and wore down the screw not letting it stop where it should and throwing timing off correct me if u think I'm on wrong track thanks for any and all replies

 

[Chris1956]

Justin, Get yourself a Mercury Brand Service Manual. It will have pictures and words.

 

[justin27]

Thank u for all the help I was messing with the piece that adjust the timing and pushed on it a little and took boat out yesterday ran awesome better than it ever has since bought it I never dreamed they would run that good I called a mechanic and he is suppose to link and sync it for me first of week so hopefully that cures everything il keep u posted

 

[justin27]

Mechanic couldn't get to my boat till next week so I am Gona try and link sync it myself my question is how do turn engine over at wot mine won't turn over in gear and all I have is a fast idle lever can I cross out solenoid and check or how would u do it thanks to all

 

[Chris1956]

Easy stuff, as my post said. Remove prop and spark plugs as described. Set throttle to max, ign on. Use a jumper to energize the starter solenoid, and take the timing reading. The engine will likely not start, which is fine.

 

[justin27]

I got my boat back from mechanic today and still won't open up he said he set timing to 10 degrees and 21 degrees it seems to me like when it warms up it runs worse any ideas what it could be he checked compression again and it was 115 on 2 cylinders and 120 on the other 4

 

[Chris1956]

Timing for your motor should be 0-9* ATDC for idle pickup and 21* BTDC for max spark advance. Any idea if he set it to 10* BTDC or ATDC?

 

[justin27]

10 atdc on idle timing he has it idling good just doesn't open up good

 

[Chris1956]

OK, maybe the idle mixture is set too lean to accelerate. Does she stumble when you give her throttle?

 

[justin27]

It does want to hesitate some when I take off

 

[Chris1956]

OK, Richen the top carb 1/8 turn first and then test acceleration. Follow with mid carb, then test acceleration. Then bottom carb, follow with test. Repeat sequence if necessary. Eventually you should get reasonable idle, and smooth acceleration.

 

[justin27]

I noticed that the rubber hose going to the fuel tank from where u fill the tank has wore into could that cause it to run bad and also where can I find some more rubber hose to put on it and what kind should I get it's Probly 2 inches around

 

[sptjet90Reflexx]

I had a similar issue with my 115 I6 also. turned out to be a bad switch box. Ran great, idled and would go but ran like crap when WOT was applied. some of the cylinders were not firing right. My upper switchbox had failed. Replaced and been good ever sense.

 

[justin27]

Thanks for the response does anyone know how to check the switch box

 

[Chris1956]

There is an extensive troubleshooting procedure for the ADI ignition system that you have at the CDIElectronics web site.

 

[sptjet90Reflexx]

My switch box actually tested fine. Just swapped it cause I couldnt figure out anything else that would cause it.

 

[justin27]

Can anyone tell me what the rod running under the flywheel from where u adjust the timing runs to and could wat ever it runs to b the problem or b in the linkage under flywheel since when I was messing around with that linkage it ran good for a little while I think I may try find a switch box and try it out