Pull Start Mercury not working

[pyro225]

Ok you may have seen i had a 50 '82 pull start that was hard to start and now has got to the point it doesn't at all...

Now i'm completely lost...

So I prime it, put it on fast idle, choked it and pulled her over 3-4 times no fire or anything. Unchoked it and tried another 20 or so times but it still does not start.

So now I'm at an absolute loss with this bloody engine and if it hadn't worked before it would have been junked!.

Recap of whats changed/been done.

Compression Test - As expected
Spark tested - As expected
Switch box swapped with a working one (used)
new CDI stator.
New Rectifier.
New Plugs.
Carbs stripped cleaned.

Please any advise now as I'm at a total loss it doesn't even pop or anything when you pull her

 

[racerone]

The term ---" as expected " means nothing to me.--------Answer with the compression values in NUMBERS.----Does spark jump a gap of 3/8" or 1 cm with all plugs in the cylinders ?----Only those answers will lead you to a solution.

 

[pyro225]

Hi Racer One, quite hard to do the gap test on my own as its pull start so i got a tester which was producing a blue spark.

Numbers

1:125
2:128
3:110
4:120

Thanks

 

[racerone]

All I am going to say is the second question was NOT answered !!------Good luck with your project.

 

[quicktach]

Use a THEXON or equivalent adjustable spark gap tester to see what voltage you're getting....

 

[pyro225]

So racer one - do you want me to leave all 4 plugs in the cylinders and then add a spare one to the ht leads to see if it will jump 1cm? I also read another post for the same ob you answered and you mentioned for the same symptoms that a wire could be going to ground to stop it starting - any ideas which wires so I could test that too?

 

[racerone]

NO,no-----You need 4 plugs in the cylinders and a TESTING DEVICE to see how strong the spark is when pulling on the recoil the way you would when trying to start this motor.-----You are having trouble with this motor.---You need to ANSWER the question.-----Does spark jump a gap of 3/8" or 1 cm, yes or no.-----Perhaps you do not realize that someone a 1000 miles away needs exact information about your motor.

 

[pyro225]

Hi racer one - what kind of device do i need? i used a tester see the video is that good enough or do i need something more heavy duty? all plugs ares the same...

https://www.youtube.com/watch?v=Quf84rvddlI

 

[pyro225]

ps sorry for long delay been waiting for a break in the weather!

 

[Bondo]

Ayuh,.... That kinda tester says it's sparkin',..... I'm guessin' it ain't gettin' gas,...

 

[pyro225]

The thing is as I said - I swapped the switch box with a working motor that's the same, new stator, rebuilt the carbs changed the plugs, checked the key - could the trigger stop it firing up? Can you mix up a bit of gas and two stroke, remove the plugs and poor staring in the cylinders or is that a bad idea ?

 

[pyro225]

hi guys - still not sure what to test with so i used a plug and made the gap as big as i realistically could about 5mm and got a strong blue/purple spark?? any further advice? i also tested the trigger wires from the switch box as far as i could to the bottom of the flywheel without taking it off with good connection... any ideas?

 

[merc_man]

Did you try spraying gas in carb to see if you can get a pop?

 

[pyro225]

hi mercman - i tried easy start which i believe should achieve the same to no avail - can i remove the plugs and spray a bit directly in or won't it work like that (maybe disconnect fuel?)

 

[pyro225]

bump

 

[pyro225]

tried spraying easy start into carbs no go but then took all four plugs out and quickly fired easy start in all 4 cylinders put back together and pulled it started and it ran for about 1-2seconds then wouldn't run again - taken the carbs off again even though I cleaned them as this would seem to indicate carbs would you think?

 

[Bondo]

Ayuh,.... It ain't gettin' gas, it sounds like,....

So, start at the tank, then the fuel lines, then the fuel filter, then the fuel pump, then the carbs,.....

 

[pyro225]

theres no fuel filter on it atm so not that - primer bul pumps and if I pump real hard fuel weeps out of both carbs...