85HP wont start /ran great for 12hrs

[topcat1965]

Hi, to all. I have a 1975 85 hp mercury. in January of 2007 I replaced the engine harness (wires from ignition to motor), the stator,replaced the water impellar and rebuilt the carbs. took it out a couple of times probably 4-6 hrs max. run time. then I let it sit while i rebuilt the deck and furniture. It sat about a year. I recently fired it up and it ran fine for about 6 hours of run time. Now it wont even start. I've checked the plugs they look ok. I'm stuck not sure what to do . rebuild or clean the carbs? P.S. I live in Arizona, so the weather may be a factor?

 

[rtpassini]

Re: 85HP wont start /ran great for 12hrs

is it getting fuel?

or bad gas?

 

[topcat1965]

Re: 85HP wont start /ran great for 12hrs

As far as I know I checked the filter and fuel came out. I also have an in line visible filter between the tank and the squeeze bulb.

 

[rtpassini]

Re: 85HP wont start /ran great for 12hrs

how old is the gas in it? more than a few months and you should put new in.

 

[topcat1965]

Re: 85HP wont start /ran great for 12hrs

ok will try tomorrow

 

[tashasdaddy]

Re: 85HP wont start /ran great for 12hrs

you check the plugs, they looked ok. But did you check to see if you have spark on each cylinder? have you considered that the motor sat for a year, and the carbs could have varnished up and broken loose, clogging the jets. have you checked compression.

it takes 3 simple things for the motor to run, CORRECT, spark, compression, fuel/air mixture.

 

[topcat1965]

Re: 85HP wont start /ran great for 12hrs

#1 145 psi, #2 135 psi, #3 145 psi, #4 145 psi. I think I'll clean the carbs, I know the spark plugs are getting juice.

 

[MadProps]

Re: 85HP wont start /ran great for 12hrs

after sitting a year Id rebuild the carbs

fastest diagnostics.......squirt fuel in the throat of each carb ....and start the motor....if she fires, you know its carbs