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New Developments in 1987 140hp Evinrude not accelerating

I havent found the problem problem yet. Its a bit too cold up here in NY to take it for a bay test. Hoping to get a nice day in January to and ill throw the boat in the water, and try the kill circuit...
 
This is a very interesting read. Could I throw my two cents in?

It runs well in a test tank but not on the boat in the WATER. I just did a google earth and checked the ambient temperature in your area (Well the whole nation actually).......3 Deg C or 37 Deg F. To me that is very cold coming from where I am LOL.

If we had temps like that down here there would be a first check of the engines cooling system. If the thermostat'thermostats are jammed open or missing the engine will never reach a cylinderhead temperature adequate for proper fuel burn. Mixture migration to main jets would be too lean for a sub cooled engine.

Check that maybe?

Regards

B
 
Thermostats were gone thru when i first got the motor. Everything looked good. I did NOT buy new ones though. It was under my impression you could run a 2 stroke motor without thermostats. Its not the best thing, but I heard its not that uncommon..

Is there truth to that?

At this point, I am willing to try just about anything. Its almost, at the point where it needs a set of fresh eyes..

I know the motor is a strong one, and when she runs right shes at top notch..
 
Post all your jet sizes, So if I remember correctly you now have the 140 reeds and carbs bolted up? If its true the reeds will be six petals and three screws on the butterflies correct ?
Post pictures if you can ...
 
You want me to replace the tach? How in the world could the tach be the cause of this problem? Like Ive said in earlier posts, Im willing to try just about anything..

Could the tach even be considered as the culprit? It just seems sooooo far fetched..
 
No news as of yet. I still have about 2 foot of snow in the boat, so working on the boat has been put on hold till it melts..I will keep you all updated as I start to work on it...
 
I had used this same Tach on a 120 Force I had hooked up to the boat prior to upgrading to the 140 Evinrude...The Force ran fine..Does that make any sense??
 
I'm just back to this site after a bit of a break and have read over your post with some interest. I myself own a 1986, 140 which I completely tore down last year. I thought that some of your responses were on to something when they suggested the sensor (trigger), it really does sound like a phantom trigger issue, but you did definately rule that out.

I did read that the carb bodies were swapped, pulled, rejetted etc etc the only thing I didn't see in that part of the conversations is whether or not you checked the correct carb bodies were feeding the correct cylinders. Looking at my notes/charts to confirm it's the intermediate jets (orifice) which are different between the port and starboard carbs. Both port carb bodies should have the no. 20 jets and the starboard ones, the no. 16's.

Might be a longshot but it really looks like you have tried just about everything else...
 
I had used this same Tach on a 120 Force I had hooked up to the boat prior to upgrading to the 140 Evinrude...The Force ran fine..Does that make any sense??
Please note a Tach MUST be set to the correct "pole" settings to function correctly. If I remember correctly it should be set to 6 ..Look at the back of the Tach is set using a flat screwdriver.
It has to do with the number or poles on the stator. For a 12 pole stator it would be set on 6, for a 10 pole stator it would be set on 5, and for a 8 pole stator set it on 4.
However you can disconnect the Tach wire (gray) to eliminate this during your testing ...
 
Ok, i checked that the jets were the correct ones for each cylinder. I ran the motor on land for 5 minutes (just to make sure she would start). I took the boat to the ramp and it ran flawlessly. I shut it down in the bay for 30 minutes while I drifted, started back up, and she ran great. No hesitation on getting up on plane, and she ran for 20 minutes at 5500rpm without skipping a beat..

I have no idea what is going on. I dont know if the problem is gone for good or if the next time i put the boat in the water she is going to act up again...


Any ideas????
 
Do yourself a huge favor, troll for a while 5 to 10 minutes plus then slowly try to bring her up on a plane...Post your results ...You mentioned the jets are the correct ones, I assumed stock as per your manual? I ask for the actual sizes for a reason.
 
I had the jet sizes written down and i cant find the darn paper. I did the trolling for a few minutes over the weekend, and the motor is acting up again.
 
"I did the trolling for a few minutes over the weekend, and the motor is acting up again"

This is exactly what I was afraid the results would be. I did ask you for some information back in November you did not respond? Help us help you...Go back and read my posts please provide all the information I am asking ..including this new info below...
Here is what you need to do..I am assuming never my style ..I am going to stick my neck out on this one...

Vro disconnected fuel mix 50:1 correct? Yes/No
I am sure you seen this engine loads up or run rich when trolling? Yes/No
Remove all your plugs, verify they are champions QL77JC4 gap to .30 snap a picture of the plugs before you clean them, re-install (We may need this info for a comparison later on)
Verify you have the 140 throttle bodies installed (three screws on the butterflies)
If you observed 2 screws STOP do not jet as I recommend below...
Verify your high speed jets are 61d (Stock) Yes/No
Verify both PORT and STARBOARD IDLE jets are (Stock) #28
Intermediate jets are the ones at the very top of each carbs the jets directly below are your idle (do mix these up)
Remove all your intermediates, if jetted stock your PORT's will be #20 and STARBOARD #16
Now here is what I recommend you do REPLACE OR RE-JET all your intermediate's to #16
I am asking you to LEAN out your intermediate mixture.

Note> both your idles and intermediates are indeed "air jets" the rule is larger the jets=more air flow=leaner fuel-mixture. Smaller the jets less air flow richer the mixture.
Note> this rule does NOT apply to your high speed since its regulates fuel flow NOT air.
Run the engine on hose then on the Lake at various speeds etc, You should see a huge change in the way this engine runs, on the hose you will see a increase in idle, adjust if needed.
Take notes you are benchmarking and needs to log everything.
Once back in the yard remove your plugs and carefully label and inspect each plugs, take a picture and post it we need to see if this engine is running lean or just right.
If lean we need to jet up and etc....
An old timer told me this trick it seems to work for me you can try it...for excessive trolling for long periods or distance like I do out the channel, Trim the engine up so all excessive unburnt 2 smoke oil drains forward in the cylinder and is pushed out the exhaust port as you hum along. Its a known fact the Looper's never likes to idle under load period.
 
I like this thread! Did you actually make sure that your cooling system had all thermostats and bypll good?

NOW! The below comment has sparked my interest........

"An old timer told me this trick it seems to work for me you can try it...for excessive trolling for long periods or distance like I do out the channel, Trim the engine up so all excessive unburnt 2 smoke oil drains forward in the cylinder and is pushed out the exhaust port as you hum along. Its a known fact the Looper's never likes to idle under load period."

EXACTLY one of my Old Dears, not like this post motor, 1976 Loop!

That is exactly what I had to do if just idling about! 3Cyl. Funny how some discussion jogs a whole pile of past life memories Eh?

I will, on that note, post a new topic about my Old MAN! 1976 Evinrude.

Anyway, sorry, get back to topic now
 
I pulled the boat out of the water earlier today. Nothing like going for a quick ride when its 16 degrees out..I didnt have time to check anything from the previous post. However, I did run the boat on plane, stop idle, troll, and accelerate again and the boat is lagging on acceleration but reaches 5500rpm without sounding like its breaking up and losing power. Keep in mind 5500rpm was very hard to get with this particular motor...I would get 5500 but it would sound terrible at that rpms..most of the time i could only push 4400-4900 and no its not prop related.
 
I know this is a very old post, but if like me you came here looking for the answer Im here to help. I had EXACTLY the same problem with my 120 evinrude. Here goes. The reason that changing the ignition parts didnt do anything is because it is a fuel problem. The reason it kicks up like two cylinders came on all of a sudden at about 3000 rpm is because that is where the two stroke powere band kicks in. The reason he can get up on plane at the end of this while test running when its really cold is because cold air is more dense than warm air.
His engine is flooding. On mine it was the manual bypass switch on the primer. It was fine, just not fully closed. 2 shops on 4 occasions didnt find it. I didn't know what it was so didnt know it was supposed to be down. On his it could be the same, or a leak in the diaphragm. Either way, I hope this helps someone to not spend the thousands of dollars that I did.
 
I might have bad grounds. But that would have absolutely nothing to do with wether or not it ran on the hose and not in the water. There has to be more to this story.
 
I'm new to this but I was going to buy a boat that would run on hose but wouldn't in the water. A mechanic said that water was a good ground. I didn't mean to come across as knowing the answer.I'm curious as to whether there is any truth to it .
 
You didnt come across bad at all. The only thing that is different about being in the water vs being on the hose is exhaust back pressure. You might have a mouse nest in the mid section.
 
Sometimes a shop can spot / identify a situation where someone is trying get or is demanding free information .-----They have a set answer to persuade those folks to go elsewhere.----And yes I know that is a bad practice, but some shops are are busy and they do it.
 
When I said the guy was a mechanic what he was was somebody who had worked at a.boat shop.he was just an acquaintance.he no longer works in the field. I appreciate you guys that do and are willing to share your knowledge.I'm retired and managed to get into this in a roundabout way and find it interesting.We live close to the georgia coast and we love to go there every chance we get. Thank 's again for helping an old guy like me.
 
I think it's unethical to go to a place of business and expect to get free information . If you think I'm.gaming this forum the ignore my questions. I'm just trying to have a hobby.
 
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