'89 110 evinrude lagging

[boatnut74]

I'm having some problems with my 110hp Evinrude. If I give it throttle slowly it has a 5-6 second lag between 2500 and 3000 rpms. After that it will take off and run fine. Under hard acceleration I have no problem. Also when starting it up for the first time for the day it will "cough" a few times while warming up. I never had any of these problems until I had a recent link and sync done. Now I can only hit 5200 rpms WOT when before I could get 6100. I'm thinking a possible timing issue.

 

[boatnut74]

Re: '89 110 evinrude lagging

I did a little research and it appears im missing the extensions from the intake silencer on both sides. Will this cause any loss in performance or do some motors just not have them. Attatched are some pics of what I'm talking about

port side

starboard side

 

[Will Bark]

Re: '89 110 evinrude lagging

Can't answer your question about what effect that would have but those screw holes look like there was something bolted on there; I would go back to whoever did the link/sync and get those extension/covers put back on. My 150 covers point backward toward the rear of the engine which is where the air intake of the cowl is located. Good luck.

 

[boatnut74]

Re: '89 110 evinrude lagging

The extensions were actually missing before the link and sync. I just never thought of anything supposed to go there until I was looking at a parts diagram.

 

[AEROCOOK]

Re: '89 110 evinrude lagging

I'm missing the extension on the port side of my 1988 110hp and it doesnt seem to affect anything.
Your problem could possibly be clogged intermediate jets. When were the carbs last cleaned? Does the motor stumble at all during the 5-6 second lag? The intermediate jets are screwed into the plastic float boals, 2 per carb. These jets shouldnt affect your WOT RPMs though so there could be more than one problem.

 

[cdn-pk]

Re: '89 110 evinrude lagging

They actually quite the engine. i have them on mine (140HP) and i take them off to do any work and i notice an audible difference as soon as i put them back on it quiets back down.

 

[boatnut74]

Re: '89 110 evinrude lagging

I rebuilt the carbs last spring. It doesnt stumble at all during the lag. I pulled the plugs and checked them. The lower port side one seemed to be an off color frm the rest of them. I'll try to post a pic here shortly.

 

[AEROCOOK]

Re: '89 110 evinrude lagging

It's looking like the link and sync may not have been done properly. How "Qualified" was the guy who worked on it?

 

[boatnut74]

Re: '89 110 evinrude lagging

I took it to a reputable marine repair shop. They have a good reputation. I called them today and told them what was going on and they said to bring it in that one of their adjustments might have "slipped" hopefully they can find the problem.

 

[emdsapmgr]

Re: '89 110 evinrude lagging

Probaly a good idea to have someone check the sync and link again. Your high rpm loss indicates something is out of adjustment. Make sure the carb throttle plates open fully at full throttle. You will have to pull the airbox cover off to check this. Those side extensions on the airbox do help silence the carb noise. Also, they slightly richen up the carb mixture due to airflow changes. Running without them may not be a problem, but it will run slightly leaner without them. If you still have them, it's probably best to reinstall them.

 

[boatnut74]

Re: '89 110 evinrude lagging

Make sure the carb throttle plates open fully at full throttle.

That was one of the first things I checked. The only other thing that has changed since last year is I put a new prop on. Same pitch but the blades seem to be a bit wider. (Its a solas) but I wouldn't think that would have much if any effect on rpm.

 

[AEROCOOK]

Re: '89 110 evinrude lagging

That was one of the first things I checked. The only other thing that has changed since last year is I put a new prop on. Same pitch but the blades seem to be a bit wider. (Its a solas) but I wouldn't think that would have much if any effect on rpm.

The prop can have a lot to do with the RPM drop even if the pitch is the same. Pitch is just one of many specifications on a prop, you have diameter, cupping, blade shape and size etc. I have 2 props that are both 17 X 13.25 one is cupped and the other one isnt. and theres about 500 RPM difference between them, the cupped one being the lower.

 

[boatnut74]

Re: '89 110 evinrude lagging

The new prop is 1/4" smaller. How do you tell the difference between cupped and uncupped? Maybe i'll put the original one back on and see what i run before i drop it off today.

 

[AEROCOOK]

Re: '89 110 evinrude lagging

The new prop is 1/4" smaller. How do you tell the difference between cupped and uncupped? Maybe i'll put the original one back on and see what i run before i drop it off today.

Probably a good idea to put the old prop back on for now as it's your benchmark in comparing your current performance to what you had prior to the link and sync. Once you have the motor set up 100% put the new prop on.
A cupped prop has a curved lip on the trailing edge of the blade, it's hard to put into words but if the concave contour of the blade (that all props have) becomes noticabley more curved at the trailing inch or so of the blade it would be a cupped prop. If you have any questions about prop science, and believe me it is a science, post your question on the prop forum.

 

[boatnut74]

Re: '89 110 evinrude lagging

I got the boat back from the shop yesterday and just as I suspected they backed off the timing. Factory calls for 28 degrees and they said the manufacturer recomends 24 degrees due to the quality of todays fuels. I usually run premium anyways as I have built several motors and know what low octane fuels can do to a high performance motor. So I guess I will have to deal with the lag or go in myself an bump up the timing a few degrees.

 

[cdn-pk]

Re: '89 110 evinrude lagging

the 4 degrees is gained from the electronic solid state components in the ignition. my 77 says 28 degrees but you set it at 24. i believe there is more threads around here with more info, that quality of fuel line is crap.

 

[boatnut74]

Re: '89 110 evinrude lagging

They set the timing under load with engine running. I've read setting it 4 degrees less but I believe that was if the motor isn't under load. They said first time they did the sync and link it was at 28 but backed it off to 24. I ran it 2 years that way and never had any issues.

 

[emdsapmgr]

Re: '89 110 evinrude lagging

There was an old OMC service bulletin from 1986 in which the factory recommended all engines from 3 cyl up through V6 should have their timing retarded by 4 degrees due to the new "no lead" gas which was just coming out. The stated exception was that if the engine was going to live on a diet of premium fuel only, that the timing could be left at the original factory setting. (the original higher timing.)

 

[boatnut74]

Re: '89 110 evinrude lagging

So if the service bulletin came out in '86 wouldn't they change the timing specs for the newer motors to compensate for this? Mines an '89.

 

[boobie]

Re: '89 110 evinrude lagging

The '98 service manual I have for that mtr says 26* BTDC WOT timing.