New to me Rude 140, sneezing, won't idle and low top speed

[ctravis595]

Just picked up an older evinrude 140 that I thought was gonna go a lot faster than 23 mph on a 15.5 ft cacci craft (old trihull kind of shape)

Other noticable symptoms seem to be maybe incomplete ignition? It sneezes loudly sometimes when I'm trying to start it

Also can't really get the boat to idle, I have to give it gas to get her started but she runs pretty smooth once she gets going

She sounds like a beast, and I've noticed other people saying these old rude 4s can sound a little rough at idle. I found one on YouTube that sounds rough like mine but stills hauls ass, I also found some smoother sounding rude v4s on YouTube so not sure what to think?

Seems like fuel pump, ignition wires, plugs were recently changed. Previous owner said he cleaned the carbs but I don't think he did a great job because he is a "car guy" like me and I haven't had amazing luck with outboards either

Worried I am running the engine with a dead cylinder, holidays are tight on money so I might see if I can just rent a compression tester, I keep the boat in the water so doing a cylinder drop off test is kind of dangerous (flywheel spinning while engine cover is off)

Anything else I should be looking for? I have a newer evinrude manual but it's hard to digest all of what it says, and it doesn't specifically mention my engine either

 

[ctravis595]

Compared to other YouTube videos it doesn't seem like my evinrude is really getting into the high rpm zone. I have no tach on my boat and no money to pay a shop

Forgot to mention the prop has a 14 inch diameter, I'm not sure how to measure both numbers yet. Seems like not much of a bigger prop would fit on this lower unit

I also suspect the possibility of some air getting in my fuel lines, saw a trick where you use a clear tube from the fuel pump to the carbs and look for bubbles, need to find some suitable clear tubing...

I apologize ahead of time for my lack of understanding with outboards

 

[oldboat1]

See if you can get a timing gun, and use that to do the drop test. Just clamp on to the individual wires.

 

[ctravis595]

Thanks I will look into sourcing one, I didn't think it would be easy

Also forgot to mention I installed these cables/throttle control myself and I have no idea what I am doing with boats, just general mechanics. Kind of "threw" the boat together and it ran good, i got the throttle and shift cables where I think they should be..not sure

 

[emdsapmgr]

What year 140 are we talking about? A crossflow or looper model? If the engine occasionally misses at idle, (sounds like a sneeze) that's likely a carb issue. One or more of the idle passages inside the carb may have some restriction inside. Once the passage gets restricted, it won't flow fuel, the engine will run lean on that cyl, and it will seem to "miss" Called a "lean sneeze."
Only way to correct that is to remove the carbs and re-clean them. You'll need something which will dissolve dried fuel, such a the aerosol Gumout product.

 

[ctravis595]

Thanks for the suggestion, I have a feeling the one tank of ethanol gas I didn't think about when I used and whatever ethanol gas the previous owner used probably prompted the restrictions

I think it's a crossflow model. From what I've seen in other videos it might be a 1979-81 based on the engine cover design

Is the pre 1995 150 v4 models in my manual a lot like the my 1980's 140 crossflow?

Edit - I planned on doing some seafoam treatment as I do with my cars, is that good enough to get the carbs clear or do they need a rebuild? Is that gumout stuff wildly different from seafoam? I just like seafoam a lot, trust it because of experience to not wreak other issues on my engines

 

[emdsapmgr]

The V4 crossflow model that is similar to your year version was made up through the 98 model year at least. All of these models share similar rotating assemblies and blocks. The later models have differences in: power trim, carb linkages, shift rod linkages, power trim control box location, VRO fuel pumps, Prop rated hp ratings, ignition components, etc. But basically, it's an improved version of your 140. The similar big brother V6 crossflow was last made in the 1991 model year.
The big thing about carb cleaning is to dissolve dried fuel gelatin which accumulates in the small idle passages. Not many chemicals will touch dried fuel. And you can't just blow the passages clear. You need to pull all the jets out and do a spray/flow test with the aerosol gumout product to validate that the passages are actually clear.

 

[oldboat1]

Ethanol is often a boogeyman -- gets blamed for all kinds of poor maintenance. Replace fuel lines (good idea to do that anyway when restoring an engine). Likewise, Seafoam often gets credited for much more than it probably should. Use it to decarb if your motor needs it, but don't count on it for carb cleaning.

"I cleaned the carbs" properly means they were disassembled and soaked, then all idle and high speed passages and jets cleaned with spray cleaner like Emdsapmgr mentions, all passages physically cleaned with small wire or similar. Maybe compressed air to finish -- has to be squeaky clean when you are through. A carb kit is normally installed.

IMO, no clear villians, and no quick fixes. Type of gas, type of oil, use of particular solvents -- all subjects of multiple threads and lots of discussion. Lots of opinions, usually some truth in all of them.

[edit. BTW, will want to be real sure your motor is cooling properly -- replace water pump unless absolutely sure the PO serviced it (new impeller). Do the usual temp tests either way.]

 

[glust]

The sneeze is usually indicative of an air screw adjustment issue. Whomever rebuilt the carbs may have screwed the jets all the way in instead of adjusting the mixture. If you aren't getting the rpms you think it may be that the prop is too big or pitched too much. it could also be that your cables are out of adjustment. Search youtube and check your manual for a section called link and sync. If the cables are not adjusted correctly you will not get the maximum throw from the cables and the butterflies on the carbs will not be all the way open. If your shift able is out of adjustment as well you can have shifting problems and start tearing out clutch dogs out of the lower unit. don't ask me how I know. Good luck

 

[waterinthefuel]

Sounds like it might be out of time. I know my dad rebuilt my carb on my 28 when it was almost new. It sneezed like hell before the rebuild and couldn't run better after. I was one happy 15 year old boy. That boat ran like a scalded dog and if it sneezes anymore its once, not 15-20 times like before. He doesn't know what he did, I don't know what he did, but he fixed it.

 

[racerone]

The trouble shooting on older crossflow engines starts with---A compression test !

 

[ctravis595]

Great advice all around, definitely gonna help me sort this out

I think the timing is not too shabby, it only really sneezes while trying to start, it's never sneezed while running. Some days it will sneeze 5/6 times before she wants to keep running, other days she starts right up BUT from what I've read, the idle and timing adjustment are the same thing on these engines so you might be onto something

I think I was scared to bite the bullet and test the compression, I hate buying engines and not knowing the compression until later. But I got the compression tester and some gumout

Gonna test the compression cold and if I can't get good readings I'll let her warm up before testing again on the lake

Also purchased some gumout and will be dissecting the carbs soon I think. Will report back

I have a strong feeling the carbs are indeed not set up correctly. While I think my compression might not be amazing I think the sneezing, bad idle and low top speed are more indicative of a fuel/air problem. Pumping the primer bulb while running provides no change, choking it while running seems to do exactly what you'd expect and doesn't provide any temporary improvement either. I don't know carbs too well but seems like the "hi speed jet" might not be doing anything at all. Not sure

I have a strong tell-tale pisser. I THINK he mentioned he replaced the water pump and I know the tell tale is the first sign of a bad water pump. Should I be worried if my tell tale is strong?

Also I read into the link and sync procedure in my manual and it discusses a lot of tools I don't have and not sure how to get?

 

[emdsapmgr]

Any crossflow will sneeze when just started. It's telling you that it's lean. You need to push in on the choke occasionally during the first minute or two that it's started. That brief choke will keep it from sneezing till it warms up and can run by itself. This is normal. No maintenance need to correct this.

 

[ctravis595]

Went to rent a compression tester and upon testing the cylinders I found a loose spark plug wire!

Pulled my spark plug and sure enough there looks like unburnt gas/oil in that cylinder while the other plugs were more dry

Compression readings 118 119 111(same cylinder that was not firing) and 119 while cold starting.

I imagine the numbers would be even better if tested at operating temp but since my numbers aren't too far apart I think I am fine and caught the issue early enough

If you are not familiar with these engines I cannot stress enough how important it is to make sure all cylinders are firing. I've installed an engine/transmission/suspension/brakes on my mercedes and often do my own troubleshooting too and I did not even recognize that the 140 was not firing on all cylinders. I knew something was wrong but she still ran smooth

Extremely excited to see how she runs with 4 cylinders instead of 3. Thanks for all the suggestions, I have a much better understanding of how to troubleshoot this engine with my shop manual in the future

 

[ctravis595]

Now for the first time since getting this engine she won't start...tried unplugging one of the spark plugs in case (maybe?) it just runs better on 3 cylinders...still wouldn't start. Very annoying

Went over the basics, everything seems plugged in. Primer bulb gets firm but doesn't get rock hard...primer bulb arrow in "up" position.

Cold start procedure - pump primer bulb once or twice (especially when reconnecting the fuel tank after fueling)
Choke on, light throttle while cranking and she usually starts up

Now she is not even starting

 

[emdsapmgr]

Is it just not starting, or is it not even cranking. Different problems. If it seems dead, you could have blown the main 20 amp fuse in the engine's main wiring harness. If it cranks, but won't start, try putting a timing light on each plugwire while cranking. See if you have any fire on all 4 plugwires. Your compression is fine for that 140. Once cyl is low, but within the 10% accepted variance. When you get it running, you may want to run a can of Bombardier "Engine Tuner" through it once or twice. It eliminates carbon around the ringsets. Usually the compression comes up a few lbs and it tends to start better.

 

[oldboat1]

fellow mb guy deserves better. Check for spark (spark tester), or the timing gun thing. She popping at all, or nothing? If the flywheel was pulled at some point, could be a problem with reinstallation.

 

[ctravis595]

Got it started and running again. Same symptoms. No idle, tops out at 26 mph on a 16 footer...going to look into cleaning the carbs now that I have the gumout.

Question-

I hear my choke click when I depress the ignition key, but I DONT see the orange lever move. I've heard it is supposed to move? It used to have gasoline dribble out of it when I would depress the choke, now it is dry.

I can move the lever by hand, I remember when I used to do this gas would seep out. No gas now. Does this sound like normal choke function?

Edit: I think it's time for a spark test

 

[ctravis595]

Also this might seem like a dumb question

But how do I know if my engine has tilt? It has a hydraulic jack mechanism on the transom mounting plate I didn't see on my Johnson 48 SPL but then again this engine is 300 lbs...

 

[jakedaawg]

Wow, sounds like we need to start over on this one....

Post results of compression test, open air gap spark test and a fuel sample into clear jar. also post model number.