Has spark, wont start

[alloycowboy]

I can put muffs on my 25 Mariner and it idles good, and hitting the throttle sounds good. Carb IS clean, I can see fuel spray thru main jet. BUT, when I put it in the water its a different story. At half throttle it surges (it takes of then it bogs down). New gas tank, new lines, new bulb,etc. Once it dies in the water it will not restart. I dont know what to do next. Any ideas? Ok, I just pulled off the fuel line going from the pump to the carb, its pumping gas. So that one problem it doesnt have. I did soak the carb in cleaner for 4 hours.... may need to rebuild it?

 

[Coloradolakeboy]

Re: Im stumped!!

Re: Im stumped!!

That sounds like a lean condition. What color is/are the plug(s)? Try adjusting your idle mixture.

 

[alloycowboy]

Re: Im stumped!!

Re: Im stumped!!

Just put new autolite gapless plugs in. I have tried to adjust idle mixture....

 

[alloycowboy]

Re: Im stumped!!

Re: Im stumped!!

Went out and cranked it up. It started after about 2-3 minutes. It did idle for a long time.... so I adjusted the idle mixture again until it sounded good. Well it ran for about 2 minutes then died. It was hard to start, and when it did it only ran for a few seconds. So im stumped lol

 

[section8]

Re: Im stumped!!

Re: Im stumped!!

maybe the fuel pump diaphragm. you drain the carbs in those two minutes and and the fuel pump isnt keeping up. diaphragm may be able to keep up with idle.

 

[alloycowboy]

Re: Im stumped!!

Re: Im stumped!!

Well I will do that next then and see. Looks like the time Im thru with this thing it will be brand new, LOL.

 

[alloycowboy]

Re: Im stumped!!

Re: Im stumped!!

Have'nt did diaphragm yet... Went out this morning to work on it and it will not start at all. Fresh gas, spark, etc, and its a no go. What am I missing? It TRIES to start, but will not run for more than a few seconds.

 

[nicknight]

Re: Im stumped!!

Re: Im stumped!!

The other poster wants you to check the color/condition of you old spark plugs. Do you still have them?

 

[alloycowboy]

Re: Im stumped!!

Re: Im stumped!!

They have alot of carbon on them. Just did compression check....50/53. So I guess its a rebuild?

 

[nicknight]

Re: Im stumped!!

Re: Im stumped!!

They have alot of carbon on them. Just did compression check....50/53. So I guess its a rebuild?

I don't know....but I don't think poor compression will cause the engine to die.
Bad sparkplug gap? Did you gap them properly?
You probably figured/know this part already.....here is a link on how to read sparkplugs: http://www.atlanticjetsports.com/_techtalk/00000005.htm

nicknight.

 

[alloycowboy]

Re: Im stumped!!

Re: Im stumped!!

They are gapless

 

[j_martin]

Re: Im stumped!!

Re: Im stumped!!

Poor compression will keep it from starting or running right. Carbon build up jamming the rings can cause poor compression. Carbon build up in the exhaust relief ports can cause it to die when immersed in water.

Sounds to me like you're in line for decarboning, (thread in FAQ on this site) compression check again, and if it's bad, a rebuild, if it's good, carbs rebuild.

hope it helps
John

 

[alloycowboy]

Re: Im stumped!!

Re: Im stumped!!

I did decarb today. And boy talk about smoke lol. Did the shock treatment w/ Seaform. Took it out on the water a Tried to run a wot. It ran pretty good. At wot it sounded like it was not getting enough gas... then all of a sudden it took off and ran perfect. Once I back off the throttle and then hit wot it was the same deal, starving for gas(I think) then it would take off. I turned it off and had hell to get it to crank. So, I will check compression tommorow. Change plugs and go from there. Any ideas???

 

[openroad2003]

Re: Has spark, wont start

open you distrupter and there is a screw holding down the point it is proboly lose i just had the same problem tighten the screw up and then your cap will open and close when it should wich will make you motor run