WOT problem with 1989 40 hp Evinrude

[chade1968bellsouth.net]

Just got the motor. I have:
disables VRO
added standard 90 hp pump mounted to block
replaces all lines
cleaned carbs
checked compression 140 +

Motor runs and cranks good
but at WOT it revs fully then cuts out over and over until you pull the throttle back. Please help

 

[mikesea]

Re: WOT problem with 1989 40 hp Evinrude

Are you saying that,the engine dies at full throttle due to loss of fuel?like it ran out.if so,you may have a restriction between the tank and the carbs,anything from dirty/corroded tank fittings,kinked fuel line,hoses can also delaminate INSIDE of the outer jacket,like a clogged artery.If you have a built in tank ,use a portable,if portable,be sure your lines are 3/8 hose and the hose barb if you have one has a 3/8 opening,if I understand your question,the demand by the engine at high rpm isnt being met,that would be a restriction problem

 

[mikesea]

Re: WOT problem with 1989 40 hp Evinrude

Are you saying that,the engine dies at full throttle due to loss of fuel?like it ran out.if so,you may have a restriction between the tank and the carbs,anything from dirty/corroded tank fittings,kinked fuel line,hoses can also delaminate INSIDE of the outer jacket,like a clogged artery.If you have a built in tank ,use a portable,if portable,be sure your lines are 3/8 hose and the hose barb if you have one has a 3/8 opening,if I understand your question,the demand by the engine at high rpm isnt being met,that would be a restriction problem ,also,why did you replace the VRO,did problem occur prior to conversion?

 

[chade1968bellsouth.net]

Re: WOT problem with 1989 40 hp Evinrude

Yes it dies at full throttle. I will go through all my lines and have another tank for my johnboat and it has new lines on it. Thanks for your time.

 

[chade1968bellsouth.net]

Re: WOT problem with 1989 40 hp Evinrude

Does anyone think it could be dropping fire to one of the cylinders... the rpm's just go from wide open to very low so fast it seems a little strange for a fuel flow problem.

 

[chade1968bellsouth.net]

Re: WOT problem with 1989 40 hp Evinrude

I replaced the VRO because I am too stupid to be sure it is working but not too dumb to mix my oil and gas. The motor sat outside for 3 years before I purchased it so thought it would just be better. Thank you for advice... i will let you know if it was a problem in the line.