1983 Evirnude 70 high idle

[jbhasaboat]

My 1983 Evinrude 70 isn't being nice to me. I just finished swapping the power head with one that actually has compression (140 each cylinder) and fired it up yesterday in the test tank (large trash can). It started quickly and runs good except for it wont slow down, its stays at 1200 rpm or above. I've checked the timing, which is at 3 degrees and made sure all the butterflys were closing all the way. I also checked for air leaks in the crankcase and carb mounts by spraying carb cleaner. I just finished checking to make sure the flywheel is lined up with tdc and the flywheel key is intact, which it is so Im out of ideas Hoping someone else has more ideas than me. Almost forgot to add that a mist of gasoline is coming out of the top carb. I think its the reeds, would that have something to do with the high idle if the reeds are bad?

 

[Daviet]

Re: 1983 Evirnude 70 high idle

Have you checked to make sure the lynk/synk is correct? There is an idle adjustment screw, have you tried adjusting it?

 

[xjdriver]

Re: 1983 Evirnude 70 high idle

In gear, or in neutral? Pretty sure thats about right for neutral.

 

[jbhasaboat]

Re: 1983 Evirnude 70 high idle

Im pretty sure its not normal, it seems like the whole throttle is exaggerated if I even think about touching the idle lever is races up to 4,000 rpm before I shut it down. I have done the lyn and sync several times as the manual instructs and disconnected it from all the cables to rule out the box or cables. I also replaced the reeds, which were in pretty bad shape, very rusty and large gaps in them compared to the newish ones.

 

[xjdriver]

Re: 1983 Evirnude 70 high idle

My factory service manual is for 1975 70hp, it says set idle to 1000-1100rpm. So its not to far off.

 

[jbhasaboat]

Re: 1983 Evirnude 70 high idle

Yep you're right, sorry about saying you're wrong without even looking for myself, this engine is making me a little crazy :facepalm: Right now I will forget about the crazy revs and focus on the running rich issue that has devolved and hopefully everything else with it will fall into place. When it does run it likes to spew gas out the carbs and oil and smoke out the back, lots of oil and smoke. I don't think its the floats, all the floats and valves are new and adjusted according to the manual. While I was cleaning them out I noticed the jets were pretty heavily tool marked from someone trying to remove them. At the time I didn't think anything of it, but could that be the problem?

 

[xjdriver]

Re: 1983 Evirnude 70 high idle

Ya it shouldn't be spewing gas out the carbs, usually floats or reeds. As long as the jets arnt oversized it should be alright. Are you running it on the hose or in water? Have you had it on the water lately? Mabey post a video

 

[jbhasaboat]

Re: 1983 Evirnude 70 high idle

Its running in a large trash can, it hasn't seen the water in 2 years now. The reeds I changed out with a set from a running engine that all looked good, the old ones in it were pretty nasty looking. As soon as it stops raining here I will post a video.

 

[jbhasaboat]

Re: 1983 Evirnude 70 high idle

The rain held off enough today for me to get a video of the suspect. I know its sideways, sorry, I didn't think about how I was holding my phone at the time. Anyway, you can see in the video that after running for awhile the throat of the top carb fills with fuel, but I don't think its a float issue because I did a little test by pumping the primer bulb while it wasn't running and it doesn't fill with fuel. This makes me think that the float valve is working properly because if it wasn't it would pour out full by pumping the primer bulb, correct?

 

[xjdriver]

Re: 1983 Evirnude 70 high idle

Your idle is a little high, 1500 in nuetral, i would lower it a little, other than that it sounds good, and i wouldn't worry about the little puddle of gas in the carb throat, ittl clear out when u get on it. You are correct about the primer bulb it should flood if its the float.

 

[jbhasaboat]

Re: 1983 Evirnude 70 high idle

That's the problem I cant get the idle to lower, the timing is as far back as it will go and all the butterfly s are shut I just cant slow it down. Also wondering if your user name has anything to do with the jeep xj, besides boats jeeps are my next hobby.

 

[xjdriver]

Re: 1983 Evirnude 70 high idle

That's the problem I cant get the idle to lower, the timing is as far back as it will go and all the butterfly s are shut I just cant slow it down. Also wondering if your user name has anything to do with the jeep xj, besides boats jeeps are my next hobby.

Hmmm, sounds to me like maybe a vaccum leak in the intake manifold since you say you replaced the reeds, did you install all new gaskets?
Ohh about the username..


Its my daily

 

[jbhasaboat]

Re: 1983 Evirnude 70 high idle

How could I have a leak at the gasket, I made it myself by hand I sure hope its there and not the crankcase seal.
Nice XJ, I really like that lift, is it a 3 inch? Here's my 93 ZJ, also my daily driver, posing for a picture hoping one day I will give it bigger tires. Me and a friend of mine tried to get into the whole offroading thing but we ending up just making a sport out of fixing the things. :lol:

 

[xjdriver]

Re: 1983 Evirnude 70 high idle

How could I have a leak at the gasket, I made it myself by hand I sure hope its there and not the crankcase seal.
Nice XJ, I really like that lift, is it a 3 inch? Here's my 93 ZJ, also my daily driver, posing for a picture hoping one day I will give it bigger tires. Me and a friend of mine tried to get into the whole offroading thing but we ending up just making a sport out of fixing the things. :lol:
View attachment 208718[/QUOTE
hopefully i cant really think of abything else that would couse high idle if your timing is all the way retarded and the throttle plates are closed, ya its a 3" lift.

 

[jbhasaboat]

Re: 1983 Evirnude 70 high idle

Its the crankcase seal :blue:I sprayed some seafoam along the seam and the rpms shot up another 200 rpm. I assume the only way to fix this is to disassemble and redo the seal, in that case the engine is done. It has heavy cylinder wall scoring so I don't really want to spend the time to redo it.

 

[xjdriver]

Re: 1983 Evirnude 70 high idle

Its the crankcase seal :blue:I sprayed some seafoam along the seam and the rpms shot up another 200 rpm. I assume the only way to fix this is to disassemble and redo the seal, in that case the engine is done. It has heavy cylinder wall scoring so I don't really want to spend the time to redo it.

I was gona say its not to bad of a job, but if it has bad scoring, might as well look for another motor

 

[jbhasaboat]

Re: 1983 Evirnude 70 high idle

I know everyone is going to attack me for this one but I was thinking about trying some permatex resealer stuff. I know its a long shot but if it works that would be great, and if it doesn't and I get bored this winter I might get around to the real repair. Being a poor college student another outboard isn't really in the cards right now so if I can patch this one up and use it for awhile that would be great ( don't worry my family has seatow :lol

 

[jbhasaboat]

Re: 1983 Evirnude 70 high idle

Well the leak was at the bottom of the crankcase where I couldn't reach. So its time to pull the power head apart because I want to go boating. Now for why I am here, is there anything I should replace while I have the engine open? Keep in mind I want to spend the minimum because this engine is living on borrowed time as it is.