Trouble shooting 1980 Evinrude v4 140 bottom cylinders dead, poor idle, maybe cranksh

[JIMTMCDANIELS]

Hi mates!

Any expertise greatly appreciated here:
I am use to 4 cycle car engines.

My first boat, an always freshwater glass 1982 Sprite 17" seahawk bowrider? has a 1980 Evinrude V4 140 Crossflow outboard, 1200 hours on the clock and previous owner said it ran ok before he parked it 6 years ago.

I put in a 12V new deep cycle battery fully charged and a new fuel pump(that shows no indication of leaking into the cylinder that pulse powers it).

With water muffs, it still does not idle well or for too long, warming up does not seem to make much of a difference, I need to fix this before going on the water.
The key push in primer seems to be working fine to help start it when needed.
With the warm up lever up, the rpm's hold fairly study around 2,000.
When the warm up lever is finally brought down, with the rpm's then around 700, the rpm needle surges up and down by about 500 rpm's, Although for a short period it did idle without surging..

While idling, I have disconnected and reconnected each cylinder spark plug wire and found that the rpm does not seem to be effected when removing either of the bottom spark plug wires, but either of the top cylinder wires removal kills the engine..

Also I find while idling, that there is low or no suction noticed when placing my hand over the bottom carburetor throat with the access cover removed, compared to the top carb throat and spraying carb cleaner into the bottom carb throat while idling does not have much effect.

I have replaced all the dried recirc system vacuum hoses and tested the 4 recirculation check valves using a syringe of rubbing alcohol as described in my repair manual and they test good, not allowing flow in but allowing flow out.

I have added an inline-see-through plastic bulb spark-test checker between the spark plug and the plug wire, to each of the spark plugs and they all show sparking while idling.

I have checked the compression on all 4 cylinders is 100psi and have removed and cleaned the water cooled exhaust plate with new gaskets, which only had some carbon buildup and viewed the piston tops and cylinder wall and rings are free and all looks great including still slightly visible factory cylinder cross hatch marks.
New thermostats and popetts and gaskets and short hoses installed.

I also removed the 2 carburetors and disassembled including jet orifice cover screws but did not remove orifices and found gas in the bowls, floats level, needle valves hold when mouth blowing through fuel line to and no carb gunk present and sprayed all holes with carb cleaner including low speed jets orifices and all seemed to spray through and I reassembled.
Visually inspected reeds with carbs removed, they appear good and I lightly touched them and they open with a oil sticky pop. I have ordered carb rebuild kits which include new needle valves.

I had removed all the spark plugs and turned the flywheel clock wise slowly with a wrench while holding up to my ear, a short hose inserted into the intake manifold throats and I find the top throats make a reed opening popping should but the bottom throats make no noise or a weak scratchy sound..
I don't notice much or any crankcase pressure resistance on the wrench while turning..

I have also replaced the spark plugs and water pump impeller and seals and changed the lower end oil and lower end top seals.

SO...advice please, seems to me from doing much reading that the bottom crankshaft seals may be bad/leaking-the problem?
I don't see much mention of these seals getting much focus in forums but I saw someone said they should be replaced every 5 years..

So I ordered the top/bottom seals kit (2 seals and 4 large O rings).
I see it said that the power head has to be removed for the bottom seal replacement.....does not sound like fun. and my manual does not go into detail on how to remove it.

But if there is no suction from the lower cylinders, how is the fuel pump being powered and if the lower crankshaft seal is bad, would this effect both lower cylinders or just one?

Seems I need to also remove the intake manifold and reed boxes and inspect them closer and replace the intake seal if it might be old or leaking, could cause no suction..

I have not checked adjusted the ignition timing sync as this requires to be on the water and assume that is still ok.

Any input is appreciated!
Thank-you for your time.

Jim

[ChampioNman]

It has been a bit since I've worked on that vintage motor so forgive me, I just can't remember if the fuel pump is mounted to the upper or lower side of the crank case. If it is the upper then that would explain why the fuel pump is working as it is drawing its vacuum from the #2 cylinder via the back side of the pump. If it is mounted to the lower side then it is getting enough vacuum to pulse the diaphragm in the pump. you can remove the by pass covers on the #3 and #4 piston and examine those two pistons for any sign of damage.
To replace the seals, unfortunately to replace the seals, the motor will need to be torn down.

[316jughead]

Welcome to the forum. It has been a long time for me too. It sounds like you don't have the OMC service manual, you should get one. Only spray a mix of gas and oil into the carbs, it's a good test. Compression tests can be inaccurate on 2 strokes, if possible do a leak down test. Total spark output tests should be done with an adjustable gap tester, I don't remember the gap for your motor, it would be in the OMC manual. I think it was 3/8", anyway the spark must jump a specified gap and be strong. You can check the idle timing and set the synk and link, timing and carbs, on the muffs. Just follow the OMC manual. Was your motor always in the Colorado Springs area, not at a lower altitude? Something to test, with the key on, test for any voltage at the primer solenoid, you should have none. Sometimes the key switch will bleed over and cause some voltage at the solenoid, this will cause an erratic idle. Spark plugs Champion QL77JC4 gap at .030? Make sure that the timer base is moving freely and returning to the stop. It might not hurt to look at those reeds, your probably going to have to test the entire ignition system. Keep us informed, omcforever is a good one to listen to, as is ChampioNman, I'm getting old and forgetful, but at one time I knew your motor inside and out.

[JIMTMCDANIELS]

Yes you are right, the pump is on the side of the upper #2 cylinder, not the lower #4 cylinder. thanks! Yes ok I'll pull the bypass plate and reed boxes today.

[JIMTMCDANIELS]

Thanks you gave me a lot to look at. My manual is on a cd I bought on e-bay.. It's some 400 pages and covers engines thru 1991.. I believe this boat has always been in CO at least the last 2 owners. Is there an altitude adjustment for these engines? I know if it was a car, you install different jet orifices for different altitudes....
It did have the gapless spark plugs but I installed the ql77jc4 that was recommended for better idling, yes .030 gap.

[JIMTMCDANIELS]

Thanks guys, I have removed the reed boxes and found the bottom cylinder reeds intact BUT both have one reed cage with a small chip in the casting at the tip of where the reed curve sits causing light to pass through and definitely air leak. Now I need to find on ebay 2 factory replacement reed and boxes.
I guess the original style is best, I'm not into trying to get crazy on the motor performance unless there's something that is a no brainer and no risk upgrade.

[316jughead]

Good job! I would stick with OEM, less problems. Yes on the sometimes jet change moving to higher elevations. Those surface gap plugs are horrible in motors like yours.

[JIMTMCDANIELS]

Sorry 316jughead, I did much reading last night and decided on new reeds:
Now I have bought 4 used reed and cage-boxes for $45 on ebay and will only need 2 to replace the 2 of mine with chips, but also ordered new CCMS 6500 rpm max Sport version composition reeds to install as they claim to get better idle, fuel economy and are durable and won't cause engine damage if they break and I don't suppose they will chip the cage like the factory originals did.


The cylinder walls look to be in alright condition, I see some vague lines but no crazy scoring.

In the mean time, I have pulled the flywheel and am replacing the top crankshaft. The new new is definitely tighter and I had to clean and polish where the seal rides had some material from the old seal on it.
I am contemplating the bottom crankshaft seal as the seals were a kit but I'm not looking forward to removing the engine to get to it.......my manual really doesn't say how to...

I don't see anywhere for high altitude orifices in online literature...
I don't know for sure of this boat was always in CO..
I wonder what I can do about checking that and how important it is..?

[316jughead]

I guess you could ask CCMS. Later

[omcforever]

There are some things you need to check/do before running composite reeds. Insure jetting is right. Some may take a reduction in Idle air orifices and maybe fatten up mains a tad. Also reed blocks usually need to be smooth/flat/no machine marks like the OEM have. You really should insure your motor is running right especially at your altitude before adding fiber reeds. 1 back fire/lean sneeze and they could be damaged. Your original jetting is idle air-#25/mids-#29/mains-67C at sea level. Do as Jerry says and contact Chris at CCMS and ask for his recommendations on prep and jetting, ect. Personally I would fix issues with motor and verify proper jetting first before I do any mods. I may have an altitude adjustment chart at home and if I do, I will see what it says. Fix your known issues first before mods. Also, never saw a metal OEM reed chip a reed block unless it comes apart maybe or ingests something. Maybe a bad or weak reed block casting??????

[omcforever]

also, did you remove the bypass covers as Fred stated for pistons 3-4 and check rings/for damage,, ect?

[JIMTMCDANIELS]

Thank-you for the expertise!

An altitude adjusting chart would be great, I'm at 6,000 ft elevation. Well, how do I check orific/jetting sizes? I mean, are there numbers etched into the orifices or do I use a drill bit in hand to see what size their hole it is or?

Ok I will ask Chris what he recommends, I didn't know the composite reeds can effect the ideal orific sizes, no ono seems to mention that do they?

Well I had read in another post elsewhere a discussion on factory reeds and one long time subscriber stated, in their experience, that the original cages seem to chip/fail more than the original reeds break, and with 2 of my 4 cages having a chip, it seems that may be a weak spot in the original design that composite reeds will avoid inflicting again..
I mean, I don't know what it would ingest to inflict a chip but the steel reed flap pounding it over 35 years I would think is suspect cause.
Ok I can wait to lap smooth the cages (as I've read how to before installing) the composite reeds later after I know its running right with original reeds.

Remove the (exhaust?) bypass plate?
yes as I stated previously I removed the exhaust bubble plate and also the piston rings were not caked with carbon and were free to spring and move and the piston tops and walls looked well:
"I have checked the compression on all 4 cylinders is 100psi and have removed and cleaned the water cooled exhaust plate with new gaskets, which only had some carbon buildup and viewed the piston tops and cylinder wall and rings are free and all looks great including still slightly visible factory cylinder cross hatch wall marks.
New thermostats and popetts and gaskets and short hoses installed."

Any discussion on the lower crankshaft seal typical failure rate or how dramatic an effect if it fails?
Maybe I should do that another time down the road say next year..?

If I do remove the power head now or later, to replace the lower crankshaft seal, are there any other items to replace while I'm in there, like I've seen mentioned a motor mount (or 2?) that can go bad although I don't know how to check it at this point, my manual does not mention any...

Many thanks again

[316jughead]

The high altitude orifice changes are in a service bulletin. I never got the chance to do any dyno testing on motors with CCMS reeds, I did with the popular composite reeds back in my day, I can't remember their name. The only difference I could see was maybe a better throttle response at mid range rpm's, some of the guy's did say they thought maybe a little better idle. There were so many problems with those reeds I never tried them. In 1980 I ran the hottest little Evinrude 140 on a 16 foot Cajun, we had shotgun starts back then, it was a real boat race. It revived my old drag race days. There are a lot of modifications you can do to your motor, mill the heads, square the ports, cut off some of the exhaust tube, match the powerhead exhaust outlet to the mid section, modify the reed cages, lean out the carbs until the plugs burned a nice color of brown, not that I did any of this, but I heard about it. We don't talk mods here. I always ran stock reeds. I ran the Evinrude 1983 235S and the 2.6 to 7000 rpm with no problems with stock reeds. With the success of CCMS reeds I can't argue against them, I don't know Chris, but I would trust him. Omcforever has good advice, my take on the whole thing, run stock and enjoy the time on the water.

[ChampioNman]

Chris is a good dude I know him personally and have been to his shop down in the Keys. You won't pick up any top end by going to them but your idle will be smoother and a little better mid range punch. While you are at it I'd take the heads off and replace the water deflectors and replace the head gaskets. I don't know any dealers down in the Springs but I do know that the crew up at Crowley Marine can answer your questions on orifice sizing. You may be better off by dropping a few pitches in prop size. I know on some of the 90* big block motors that they did offer high altitude heads.

[JIMTMCDANIELS]

Thank you very much for the discussion and info 316!

Yes well very interesting to talk about and learn anything I can from you would share!

Please feel free to elaborate or even correct my new understands on the fun and interesting discussion below of boating.
This is my first boat and a 2 cycle engine and there is so much to learn about it all and I still haven't had the boat in the water yet:

I do have an open ear to any easy/reasonable/inexpensive methods/discoveries of improving the motor performance or idle or fuel economy without sacrificing the reliability or fuel economy or idle and it seems there isn't anything out there that fits all those catagories besides say:

-proper tuning up synching/high altitude orifices/HHO kit..
or I have read about drilling vent holes in the aluminum prop to increase hole shot performance and a few said that removing the exhaust filler blocks actually oddly enough improves the 140 motor all round.. (see reference at bottom)

I did see in other posts, people asked what they could do to a 140 E/J to increase performance and guys that seemed very knowledgable, generally speaking said nothing within reason and to just get a 3 cylinder 150 or bigger motor instead to really pursue more hp. (see references at bottom)

I mean they and you talk about some mods that sounds like they require a machine shop to perform, even the ones that sound easy I don't think I could or would be comfortable doing myself even if I go to Harbor Freight and get, not sure what tool to do some of what is mentioned.
I have read about people doing mods that sound like these on other motors and sometimes they saw little gains, just seems risky trying to reinvent/reengineer something when I can have trouble just restoring to factory condition setup LOL

You say to Lean out the carbs till the spark plugs are a nice brown soot? Is that the ideal sign of fuel mixture set for fuel economy and performance?
If so, I would be very interested in learning how to get that right but idle, intermediate, high speed orifices, ...I'd have to learn how it's done. I guess I'll have to google it although I haven't seen discussion of how to choose orifics sizes and my 400 page manual does not either.
Seems if I can find out what OMC recommends for high altitude and make sure that's what is installed, may be as far as I need to go with that concern..?

I was initially a bit disappointed when I learned/read that my 1980 140 hp rated at the prop is really only like a 115 as now modern ratings, since about 1985, are at the powerhead.
I was also a bit disappointed when I learned that the later 140's were a more powerful, like new invention called the "Looper" combustion flow design instead of my "crossflow" design.

Also I know mechanics say combustion engines loose some 3% HP for every 1,000 feet of elevation, because of the thinner air, so here at 6,000 feet, it's down some 18% where I live in CO (I still remember being amazed at the family 1966 Ford 390 4b station wagon being capable of squealing the tire across the intersection down low in AZ while on a family trip, almost like it was turbo charged down there. LOL)

But then I read that the looper design for engines has been around for a long time and has some disadvantages compared to the cross flow in that the cross flow is better suited for trolling, has lower end torque and better fuel economy, sounds like a better fit for me.
I don't do fishing but I have a few friends who do and I don't plan on speeding around the lake non stop all day.
I may want to "troll and fish" for the people to meet and get to know on the lake instead of top speeding around all the time. Maybe if we aren't speeding around I can run into you 316 and we can chat about boats!? 316.. oh you aren't a borg are you!?? .. cause that would be pretty cool ! Sorry my Star Trek fan in me coming out LOL

Well my boat plate says it shouldn't have more than a 115hp motor anyways and here in CO the speed limit for the entire state is 40mph and careless/reckless driving are all not legal and I have read online of people being ticketed for these offenses...

Also I have read when pulling people whether skiing or wakeboard or tubing, 25mph should not be exceeded as it can be very dangerous for them if they fall and I don't want to hurt anyone..
Also having too much HP on the boat can increase the chance of capsizing and sinking my sprite seahawk 17' open bow glass tri hull boat and I want this boat to last a very long time, until they come out with boats that fly or something LOL.

Also I have read and seen in youtube videos how the HP increase needed to increase a boat's top speed is a very very steep exponential curve including crazy fuel consumption increases, crazy pursuit for say 5mph faster.....

So I mean I see it on youtube with cars and boats where insatiable people go to great lengths to squeze some more HP out of their engines and some seem never satisfied for long.
It often ends with them blowing them up or crashing the vehicles and even people getting hurt, doesn't it?

I see much discussion on the net about vehicle mods yet very rarely are the disadvantages to mods ever discussed at all like bad idle, noise, premium gas, knocking, etc.

I mean I have seen some small engines on boats that can really scoot around impressively.
So I'm assuming that my factory 140 will be all the power I need.

I've read how we are called the Human Race because us adults become addicted to our mind thoughts always racing racing in energy highs.

For me, when it comes to automobiles, I generally strive to restore that original factory balance between comfort and ride and fuel economy and smoothness and quietness and balanced practicality of a vehicle, the sweet spot for the engineers and for me.


References:
Exhaust filler blocks removal
https://www.screamandfly.com/archive.../t-192347.html
-
140 performance increase mod discussions:

http://www.boatracingfacts.com/forum...crossflow-mods

https://www.screamandfly.com/archive.../t-173795.html

http://www.marineengine.com/boat-for.../t-410042.html

[JIMTMCDANIELS]

Thank-you ChampioNman!

Smoother idle and mid punch and no risk of a broken composite reed taking out a cylinder or chipping the reed cage sounds like an improvement over the old technology reeds.
-
Thanks for telling me about the problem of not replacing the important water deflector inserts!
I did not know what these were but found a good discussion (ref. below) that educated me so I will buy some 3/8" double wall fuel line hose to use and also replace the head gaskets.

I had tested my overhead horn by grounding so it's good to know that will work if needed.
-
From what I've read, having too aggressive a prop that lugs the engine into low top end rpm's is what is very hard on an engine.
When I get the boat in the water, then I'll be able to see what the top rpm is and so whether the prop is a good size/pitch or not.
My understanding is the current prop is an Aluminum 3 blade 391198, 13 3/4" x 15P, 13 spline.
Since my engine max wot is 5,000 rpm, that or slightly higher is my target, from what I have read.
-
High altitude heads?! Hmmm I'll have to try to google that, I wonder what the difference is.. seems with old carbureted cars, for high altitude you would rejet the carbs leaner and the idle mixture screw and increase the ignition timing advance...
for the 90 deg but not the 60 deg..? hmmm
-
Ok thank you also for the tip to contact Crowley Marine for the orifice sizing and I will also google to see if there is also a chart online.
-
Thanks again!

Water deflectors ref.
https://forums.iboats.com/forum/engi...77-johnson-140

[316jughead]

OK. my 2 cents worth, why would anyone remove those filler blocks. For goodness sakes that is a tuned exhaust system. In my day you could buy the bubble back but not those filler blocks, guy's would give their left nut for a set. Don't ever think that swallowing a reed will not cause motor damage, composition or not. The reed may not cause any damage but other damage can and will happen. You will gain more from a good, proper fit stainless steel prop than any minor modifications. Omcforever is correct, get your motor up and running and then decide what other things you want to do. Most OMC motors came out plenty rich on the main jetting, for their protection. When I milled .020 to .025 off the heads, depending the combustion chamber style, I only had to go down one jet size, sometimes two, to get my desired burn on the plugs. Also with some mods and some motors, double or at least more oil is required, I always ran more oil when I fished a tournament. I am very proud to be a part of this forum, a no BS site with certified master techs and other members with extensive experience and knowledge. We have had some get on here with their BS, but they don't last long. You haven't heard from him yet, but we have a God Father that doesn't let us get to far out of line, Mr. Seahorse. This man knows these motors, we've had our discussions, but when he talks I listen. ( except once )

[ChampioNman]

^^^^ You don't want the infamous Smack or the Dunce cap.

It has been a long standing rule here that we don't do mods, that's what Scream N Fly are for. Stick around here a while and you'll see it is scary enough to see that some folks have a hard time with a spark plug wrench never mind letting them take a die grinder to a cylinder sleeve. One false move and you've gone from a screamer to an anchor. Every time you make a hop up to your motor you are decreasing the life span of said subject. Remember most of those guys over there have no worries about rebuilding their motors after a few good runs and say Oh Well should it pop. That's why we stick to stock performance motors.

[316jughead]

Hey Jim, if you still need the high altitude jet info, I dug out my service bulletins. Bulletin 2217 has the info and the orifice chart for your motor. IM me your e-mail and I will send you that info. I was thinking, since you live in mountain time zone and I live in central time zone, 8:00 here is 7:00 there, will you receive the info before I send it?

[316jughead]

Glad you got the info, I had fun looking thru the old service bulletins and my notes made years ago.