1985 90hp Evinrude bogs above half throttle

[TBarCYa]

I have a 1985 Evinrude 90hp engine that when I started it yesterday ran find and was running at 3/4 throttle for about 15 minutes when it suddenly bogged down and from then on it will run terrible above half throttle. Initially, pushing the key in (activating the choke) would allow the boat to get up on plane and half throttle (without the choke) would keep it there, but it stopped being helpful after a short time. I took the carbs apart and blew cleaner thru all of the orifaces and adjusted the float level and everything is clean and the floats are adjusted properly.<br /><br />I'm looking for suggestions on what may be causing my problem. I have a set of recently rebuilt carbs that I can install but I'm not sure that the carbs are the problem since they are clean and seem to function correctly.<br /><br />Someone suggested that it could be a timing issue but I don't know how to adjust the timing on this engine.<br /><br />Any suggestion on what may be the problem would be very helpful. <br /><br />Thank you in advance for your assistance.

 

[Goodoleboy]

Re: 1985 90hp Evinrude bogs above half throttle

Check for air leak in your fuel line. It can happen all of a sudden just like you have described. A small air leak will let the motor run at low rpms but wont get up past mid range.<br /><br />It could be other things such as timeing. but look for the simplest things first.

 

[TBarCYa]

Re: 1985 90hp Evinrude bogs above half throttle

Excellent... I will replace all of the fuel lines tomorrow then.<br /><br />Is there a simple way to adjust the timing??

 

[Goodoleboy]

Re: 1985 90hp Evinrude bogs above half throttle

Do you have a manual for this motor. If not its very difficult to adjust it corectly.<br /><br />If you do have one then its fairly simple to check and adjust.

 

[TBarCYa]

Re: 1985 90hp Evinrude bogs above half throttle

I do have the manual but I'm 35 miles away from it right now. I will have the manual with me tomorrow when I am working on the engine tho.<br /><br />Thanks again.

 

[TBarCYa]

Re: 1985 90hp Evinrude bogs above half throttle

I went out today to work on it and noticed that no matter how many times I pump the primer, it never gets hard like it used to. When I switched to a different hose (with everything else being the same) the primer bulb does get hard. In both cases, the engine seems to run the same but since I'm only starting it with earmuffs, I have no way to load test it or to really try it above half throttle. Could the lack of pressure in the primer bulb be indicative of the cause of my problem or should I continue to investigate?? I don't want to drag the thing all the way to the water unless I'm reasonably sure it will be successful.<br /><br />Thank you.

 

[Goodoleboy]

Re: 1985 90hp Evinrude bogs above half throttle

Yep could be the cause. Can you back the trailer into the water start it up. let it idel till warm as usual.<br /><br />Then open it up. If I were you I would check timeing at idel just to see if its still ok.<br /><br />But I wouldnt start takeing things apart until you see how the fuel line works out.<br /><br />Mabey we should all build a swiming pool that we can back the trailer down into and play around with or boats till we geter working.<br /><br />First time I win the lotery Ill do just that!

 

[TBarCYa]

Re: 1985 90hp Evinrude bogs above half throttle

Hahaha... At this point, if I had a pool, I would try that because the nearest body of water large enoguh for the boat is 45 minutes away. I have a large drum that should be big enough for me to lower the prop into and fill with water. Do you think that would work??<br /><br />I was reading the Clymer manual and it states that there should be a constant flow of fuel from the fuel pump, but I thought that it is a diaphragm type and therefore would pulse?? Mine pulses and puts out a fairly even amount of fuel with each pulse so I don't believe the pump is bad unless I'm incorrect and that there should be a constant flow from the pump. <br /><br />I'm still planning to replace all of the rubber fuel lines under the engine cover but I haven't gotten to the store yet to get them. I guess I'll do that tomorrow and if running the engine in the drum is an acceptable way to test it, I'll try that before heading to the ramp.<br /><br />Thanks again.

 

[CLICK7]

Re: 1985 90hp Evinrude bogs above half throttle

I had some what of the same problem on 81' 90hp<br />except mine bogged out at full throttle,my primer bulb would never really get tight either replaced the fuel line connector at the motor.It ran fine after that.the primer buld now gets tight like it should also.

 

[TBarCYa]

Re: 1985 90hp Evinrude bogs above half throttle

I can hear some noise coming from the connector at the tank so that's probably where the problem is but I think I'll replace the whole hose just to be on the safe side. It also can't hurt to keep some extras of those connectors around just in case this happens again.

 

[CLICK7]

Re: 1985 90hp Evinrude bogs above half throttle

The one on mine felt loose but it wasnt leaking any gas, but might have been sucking air,there pretty cheap so it wouldnt hurt to replace.