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Help no start merc 37

megman

New member
"Need help, engine started and

"Need help, engine started and ran fine, I rebuilt the carb last week and after installing it the engine wont start, the fuel is fine but getting only 6.5 volts from the coil with the key on, checked purple wire going to coil off and 12volt there but when connected still 6.5 tryed new coil and still same result."
 
"There is a purple resistance

"There is a purple resistance wire that run from the choke to the ignition. Resistance wire means you WILL get LESS THAN 12V at the coil. Just make sure you put all the wires back where you found them and that they are connected good, clean and tight!!
2 things must be present to run your engine,
1- Fuel
2-spark
You say the fuel delivery is fine-How do you know?
On to step two,
Pull a spark plug, look at it, is it all wet and stink of fuel? If it is, you have flooded engine and fouled the plugs. If it looks good, hook the spark plug to it and ground the plug. Crank the engine. Check to see if a spark is jumping across the electrode. Please be carefull when doing all of this. Report back your findings!!
MY 2 CENTS Chris"
 
"The boat has two engines and

"The boat has two engines and I checked the volt on the engine that is working with the key on and it gave me above 12 and starts fine, the motor that is not I checked the fuel looking down the port and moved the butterfly and it flowed fine, the purple wire seems to be overheating it gets very hot. The spark plugs are fine I checked them. but there in no spark with the spark plug tester connected to the lead wire. I am wondering if a ground is missing or shorted I put back everthing the same as I took it off."
 
"Megal
Just because one engin


"Megal
Just because one engine is giving you 12v doesnt mean the other engine should be.
You may have an external resistor wired in on one engine in which case the voltage at the + side of the coil will be much less than 12 volts, where as the other engine may have an internal resistor coil fitted and then the voltage at the + terminal will be 12v or greater with a good battery.
If there is a resistor wire in the harness it will get hotter than the rest of the wires.
You need to determin wether or not your coils are resistor or non resistor coils and then let us know.
I would suggest that if the boat ran OK before you serviced the carby, unfortunatly you have done something wrong or damaged something whilst doing the job, why was the carby overhauled ??
Go back and double check everything you have done and if you overhauled the carby using the instructions that came in the kit instead of setting it up as per your manual you may have used incorrect settings.

Peter C"
 
"You are probably getting 12V

"You are probably getting 12V on the good engine because you are checking it with the points in the open position! The circuit is not closed, current is not flowing and there is NO voltage drop. Your bad engine has a closed or grounded circuit and you are reading the voltage drop across the coil.
Check your interrupt switch if you have one. Look at this wiring diagram(link). The gray wire will ground your coil, if the switch closes. Otherwise check inside of your distributor. Do you have some sort of neutral kill switch at the throttle? That could also be a possibility. http://www.members.aol.com/cdrr61/470_wireing.jpg""
 
"Thanks Chris the switch on th

"Thanks Chris the switch on the side some how the spring got out of place and it stay off, after putting it back in the right place it started perfect."
 
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