please help, wits end

t.martin

Petty Officer 2nd Class
Joined
Apr 27, 2005
Messages
121
1986 85 hp. I have never had this motor run for more than 5 seconds. I have good spark at all 3 cylinders. I have fuel at all 3 carbs. Compression is between 115 and 120 on all 3 cylinders (new pistons and rings). Flywheel mark lines up with mark on intake when #1 is tdc. Rebuilt fuel pump. Fresh gas. New plugs. When I do get it to start it is usually for just a second or two and if I crank it again it will usually crank hard and then backfire. When I look at the plugs it looks like #1 and #2 have never ignited (clean) as a matter of fact #1 looks like it has condensation on it, but I don't have it hooked to muffs(going to change impeller if i get it running). Sometimes I can see gas spit out of the top carb about two feet. Can it be that far out of time by adjusting the timing on the trigger? Can it be something internally they did wrong when they rebuilt it? Could it be a bad trigger? Almost forgot I also checked the reeds and they are flat and look good. Any ideas will be greatly appreciated.
 

novicetech

Petty Officer 1st Class
Joined
Jan 19, 2004
Messages
267
Re: please help, wits end

T, first Check for spark at all three plugs, by removing them one at a time and holding them up to the plug holes with insulated pliers, while an assistant cranks the motor. You should have blue spark at all three plugs. If you have spark at all three plugs get yourself a manual and rebuild the carbs and use it to set your timing.
 

Docdoc

Petty Officer 2nd Class
Joined
Mar 3, 2005
Messages
196
Re: please help, wits end

Sounds like your carb(s) is/are flooding. Get rebuild kits at Napa auto parts and rebuild them. Set idle mixture screw about 1 to 1.25 turns out from lightly seated and adjust to specs from there. Do not adjust motor to run too lean, or you will cook a piston. Do not run the motor without a source of water for the water pump. If nothing else, put it in a trash can filled with water.
 

t.martin

Petty Officer 2nd Class
Joined
Apr 27, 2005
Messages
121
Re: please help, wits end

The carbs on this motor can't be rebuilt (walbro). The seats are pressed, so I cleaned them real well with power tune and blew them out with compressed air. I also adjusted the floats. I am pretty sure it is timing. I have another motor for parts. I have swapped everything, but the trigger. I am going to try that tonight. The spark is strong and bright blue on all three.
 

boatsmitty

Cadet
Joined
Jan 4, 2004
Messages
22
Re: please help, wits end

If you have a volt-ohm meter with peak voltage capture, you can check the trigger output. you will need a copy of the page in the manual that describes the test procedure and readings.
 

t.martin

Petty Officer 2nd Class
Joined
Apr 27, 2005
Messages
121
Re: please help, wits end

I checked the resistance = 50 per set. The problem is none of the wires are marked coming frome the trigger. The parts from my parts motor had a terminal board, this motor has plug ins, so I had to cut and splice. I might have crossed #1 and #3 cylinders being both use orange and green wire sets. I am going to put a timing light on it and try to figure it out.
 

chuckz

Chief Petty Officer
Joined
Aug 22, 2004
Messages
625
Re: please help, wits end

Forget about the timing light. You're already backfiring, it's not going to get any worse. Reverse the two sets of wires and try it. If it starts, extend your arm away from your body, bend it at the elbow and then slap yourself :)
 

t.martin

Petty Officer 2nd Class
Joined
Apr 27, 2005
Messages
121
Re: please help, wits end

These wires come out in a clump, you would think they would be color coded for each cylinder. Trust me, if this fixes this %*%$# motor I will do more than slap myself.
 

t.martin

Petty Officer 2nd Class
Joined
Apr 27, 2005
Messages
121
Re: please help, wits end

IT RUNS!!!! I put a timing light on it to find that #2 and #3 were switched.
 

chuckz

Chief Petty Officer
Joined
Aug 22, 2004
Messages
625
Re: please help, wits end

Let the slapping begin!
 

t.martin

Petty Officer 2nd Class
Joined
Apr 27, 2005
Messages
121
Re: please help, wits end

I actually celebrated by drinking myself into a light coma. I still blame force for not color coding their wires.
 
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