[duke.2010]

i have mercury 500 thunderbolt and i have a starting problem and i dont get more that 15 mph out of the engine i think its a timing problem but i dont know how to go about fixing it and i need help with that asap

[Yepblaze]

It's usually not a timing issue.

[duke.2010]

so if its not the timeing what is it then ?

[rafteye]

Weird. I am having the same issue. I believe it to be a fuel issue. It sounds like it's starving for fuel. I'm going to make sure my fuel lines are completely cleared and try a carb cleaning. I'll let you know if anything works!

[Yepblaze]

It's usually something like poor compression or a fuel delivery issue.

Sometimes it can be ignition (even timing), but from seeing all the post that come by, I'd guess mostly fuel.


Run a compression check to make sure you have a solid foundation on which to perform repairs.

See, that if by squeezing the primer ball in the gas line while operating the performance immediately improves.

Look to see if gasoline dribbles out of one or more carbs.

Run those diagnostics and get back to us.

Of course, if by chance you, or someone has somehow messed the timing up I guess It could certainly be a timing issue.

[rafteye]

My issues has been resolved. It was actually a linkage problem inside the control box. There was a burr on the throttle cam that was preventing the throttle from opening all the way. Also found a couple of kinks in the cable itself. Alll works great now! You might take a look in your control box. Good luck!

[duke.2010]

i hope that is the case if not i will add another posting to this form