Evinrude 140 V4 1989 missing @ WOT

[mt78robalotank]

Hey there fellow boaters. I have a 1989 Evinrude 140 that I have been working on since I bought the the new to me boat back in July. This is my very first boat so I am really new to outboard engines. I had some very helpful relpys from the fellow Iboat members in the past. If it weren't for you guys I dont know if I would have a decent boating season. I have recently found a good boat mechanic that is reasoble but I am a hands on kind of person that would rather learn how to work on my stuff rather than pay a fortune to someone else to do it for me.
I have recently replaced the power pack and stator and rebuilt the carbs on the motor and it idiles and cranks like a top. However when I goose the gas it falls flat on its face trying to reach WOT. If I keep the throttle about halfway to 3/4throttle it runs fine anything above that and it surges like someone pulled the throttle back. Any ideas as to what might be happening?

 

[oldcatamount]

Re: Evinrude 140 V4 1989 missing @ WOT

Since you have re-built the carbs, I'm assuming the high speed jets are clean. It could be the fuel pump is failing when you reach higher RPM's or there is a restiction in the fuel line somewhere that doesn't allow maximum flow of fuel. (just thoughts)

 

[twostroke87]

Re: Evinrude 140 V4 1989 missing @ WOT

when you get to that point where it falls flat, at the same time that you try to accelerate to WOT, push your key in to activate your fuel enrichener (electric choke) If the engine seems to speed up towards wot, then you know you have a fuel problem, whether or not something is wrong in the carbs or fuel pumps or what.

 

[Bob Gilvary]

Re: Evinrude 140 V4 1989 missing @ WOT

Just for kicks, check and see that your cam follower roller has not deteriorated, cracked and fallen away. If your roller is small in diameter, it's outside sleeve portion is gone.

 

[mt78robalotank]

Re: Evinrude 140 V4 1989 missing @ WOT

Just for kicks, check and see that your cam follower roller has not deteriorated, cracked and fallen away. If your roller is small in diameter, it's outside sleeve portion is gone.

Hey Bob, sorry I took so long to reply, Thanks for the reply I looked at the cam follower and it seems to be ok. It is a black cylindrical plastic peice. You mentioned an outside sleeve portion. What should the cam follower look like? Am I missing something?

 

[mt78robalotank]

Re: Evinrude 140 V4 1989 missing @ WOT

Two Stroke, Thanks for the reply. I have tried this in the past but it does not seem to change when I engage the choke. What does that indicate to you? I performed a linc and sinc after rebuilding the carbs and that cleared up my ideling issue and starting issue. Could it be a timing issue. I have not checked this yet. I need to accquire an appropriate timing light first. Which one do you reccomend?

 

[nymack66]

Re: Evinrude 140 V4 1989 missing @ WOT

Downsize your intermediates jet and test ..Post your current jet sizes and location and I can recommend some numbers for you. Your current stock size should be .54? Try a set of .52 and post results...

 

[ezeke]

Re: Evinrude 140 V4 1989 missing @ WOT

What is the approximate RPM at breakdown?

Is S.L.O.W. engaging?