55 Evinrude problem, please help!

[ronsealdeath]

Hi there, I have a late 70s Evinrude 55 with fixed jet carbs and a problem with running in the water. Apologies but this is another 'my engine does this, what's wrong?' threads but I have run out of money so need all the help I can get!

Ok here goes, engine was bought having been standing for unknown period. Ran pretty roughly at idle on 3 outings we have had on it and in the driveway but it started first time always. Always would stall when put in gear and so needed a bit of throttle straight away to get it going at high speed which was always pretty smooth to be fair. Flywheel nut kept coming loose and flew off a few times. Now the engine was probably running for a minute or so with no flywheel nut until we noticed! Loctited it on and it stayed put. Next outing we were going fine, usual stalling at low speed, but suddenly at WOT it stuttered, so I backed off and it died. Wouldn't start for a minute then fired with loads of choke, ran for 10 secs then died even with plenty off travel on the warm up lever.
Paddled back upon which I was told by the neighbour who is an expert on Evinrudes that it sounded like fuel starvation. So I rebuilt the fuel pump for good measure and also noticed that the vac pipe leading from it to the engine was split, so I replaced it. I have never rebuilt a fuel pump before but its not inconceivable that I may have screwed it up? The diapragm I put in from the rebuild kit wasn't loose like the one I took out? Is this correct?
Anyway, bear with me sorry this is a long story!:redface:
Also rebuilt the carbs and sprayed carb cleaner through them. Haven't got access to compressed air. Also couldn't get access to the low speed orifice as the screws are chewed up a fair bit so they are uncleaned.
Put carbs back on, lync and synch, she started up ok, still rough idle but idled ok at about 1000 on the muffs. Did a decarb with Redex, got loadsof crap out. Checked compression which was 95 psi COLD with no throttle, on each cylinder.
Plugs are new with 0.03 gap.
Took it out yesterday, fired up first time, warmed her up for 5 mins, idled at around what was set on the muffs, little lower but didn't want to stall really. Put in gear and didnt stall, gave it some throttle and it sounded like it was missing a bit, gave it WOT and it was at about 80% of power we had a while back, still sounded a bit rough. Went on for about 5 mins at just under WOT, backed off the throttle and it just died straight away. Tried to restart but would just cough a bit and not start. Gave it loads of chole and it fired for 10 secs then died. Same story for 30 mins. Plugs looked dry when I took them out, no oil deposits. Pumped bulb, gave loads of choke and it would go for a bit longer, say 15 secs, then die.
Fuel is fresh but my TCW3 oil is about 10 yrs old! (I know but it was there!) I have 5 gallons of mixed fuel here with no way of using it!!!!
Took her home, got it fired with loads of choke then using the throttles direct on the carbs I could keep her going above about 3000 RPM but below that she wanted to die out. It would just die otherwise then refuse to start again. Both cylinders warm to touch.
Anyone got any ideas? Anything I can do on the cheap! Been offered some carbs off a 50hp johnson of same year for quite cheap. Are they worth a try on there? Is it worth trying to get into my low speed orifices? I guess so but will need to make a tool to get the screws off.
Any help would be awesome. I dont want to give up on her as she ran great at high RPM before and I want to get her going nice and smooth.
Cheers
Al
Wales

 

[Daviet]

Re: 55 Evinrude problem, please help!

OK, lets start at the beginning. You need to post the model number so we know what engine you have.
There are some basic checks you need to do first, check the compression and spark, the spark should jump a 7/16" air gap and be bright blue.
If those check out ok, move on to the fuel delevery system. Does the primer bulb pump up firm, is the filter screen clear? Do you have fuel pressure from the pump? It sounds like you could not clean the carbs properly, that might be a major portion of your problems.

 

[ronsealdeath]

Re: 55 Evinrude problem, please help!

Hi there it is a 55975C. Thanks for the advice, going to check the spark gap tomorrow using a home made tester. If that checks out I will take the carbs apart and do a clean again. I'll try and borrow a compressor this time perhaps?
Cheers
Al

 

[Daviet]

Re: 55 Evinrude problem, please help!

Check the compression, could be causing you problems.

 

[jtexas]

Re: 55 Evinrude problem, please help!

55975 is a 1979 model number http://evinrude.cust.shopatron.com/media/document/ModelNumberReference.pdf

When the flywheel nut came off, was the flywheel key ok? If the flywheel isn't torqued to the specification in the manual, dry (no loctite), it is prone to breaking the key. That throws the timing off.

There's a core plug on top of the carb, that will allow access to the back side of the idle orifice. Drill or punch a hole in it and pull it out. You should have got replacements for those in your kits, they look like metal contact lenses. Drop it in place and flatten with a hammer and punch. A socket works pretty well for that. I'd give that a try first, if it doesn't help carefully drill out the screw plugs. Don't damage the carb body, it'll be tough to replace. Replacement screws are about 14USD, hopefully you can source them locally.

Revving on the muffs is a bad idea, way more likely to do harm than to help with troubleshooting. Without backpressure on the underwater exhaust, even a crappy running motor can sound great on the muffs, so you won't know how well it will perform in the water until you launch the boat anyway. And, here's a couple recent examples of the dangers of revving a 2-stroke outboard on the muffs:
http://forums.iboats.com/showthread.php?t=430070
http://forums.iboats.com/showthread.php?t=430437
Not to mention which, without a load on the motor, RPMs are slow to come back down when you reduce the throttle. With the throttles closed and the motor still revved up, you get a moment of inadequate oil.

Loose pump diaphram, sounds like it was ready for repair. If the carb bowls are full when you shut it off, the pump is good. If your fuel line is holding pressure the pump is good. But note that if either those conditions is not met, there are other possible causes besides faulty pump.

Redex...is that composed of naphtha and ATF?

I don't know the shelf life of TCW3, I suspect it's ok, but if there's any doubt, a couple gallons of premix at a time, added to a full tank won't hurt your vehicle -- fuel economy might suffer a tiny bit, but modern automotive engines have sensors and computers to deal with that sort of thing.

 

[Daviet]

Re: 55 Evinrude problem, please help!

I forgot about the flywheel nut, do as jtexas suggests and check the key and torque it down to proper specs, and leave out the loctite.

 

[ronsealdeath]

Re: 55 Evinrude problem, please help!

Hi there I dont blame you for forgetting the flywheel nut, I wrote a lot in that post so I appreciate you all taking the time to read it and get back to me.

I torqued the flywhel nut up to 105lbs before but with loctite as well. I think it was that torque, but I got the figure from the shop manual so whatever that said.

If I take the flywheel off do I risk throwing timing out? I will check the woodruff key for damage tomorrow as well if I can get the flywheel off without a puller. It was loose when the nut flew off so I guess the key may have got damaged.

There is a lot to check but should be fun trying it all. Me and my mate lost a bit of faith in her yesterday but I feel a bit more inspired now!
Many thanks
Al

 

[ronsealdeath]

Re: 55 Evinrude problem, please help!

Oh yeah, Redex is a fuel additive we get here in the UK. It states it can be used to decarb engines but I don't know if its as good as seafoam etc... They are expensive to buy here so I used redex. Got a lot of white smoke and a dirty driveway!
Muffs will be consigned to bin in favour of a big bucket!
cheers
Al

 

[Daviet]

Re: 55 Evinrude problem, please help!

Make sure the water level in the bucket covers the water pump.

 

[ronsealdeath]

Re: 55 Evinrude problem, please help!

OK, got the low speed nuts off the carb in the end with a v. big screwdriver. Got some fishing line in there to clean them through and got some carb cleaner in there.

I used my home made spark tester and got it jumping an 11mm gap (7/16) ok. It wasn't a very thick spark or anything, like a hair line? But it was cracking as it arced. I guess the main thing is that it jumped the gap ok.

Took the flywheel nut off but couldnt get my flywheel off. Ordered a puller from fleabay so should be able to look at the key this week.

Re-gapped plugs to 0.03. When I took them out they were absolutely covered in carbon. I guess this was as a result of me giving it so much choke to get it to fire up. So plugs are gapped and clean now again. On the water last week after the engine died, the plugs were clean so fouled plugs appears to not be an issue when engine is running.

Like I said before compression was 95psi cold on each cylinder.

Will let you know how the key looks. I'll check the fuel pump pressure after that.

Thanks
Al

 

[F_R]

Re: 55 Evinrude problem, please help!

Whoa!! Get your eyes off the carburetors and on the obvious problem. You say it ran with the flywheel nut off? You can bet the farm that the key is sheared and you will be extremely lucky if the flywheel and crankshaft aren't destroyed. That is what happens when some unqualified person works on motors and didn't install the flywheel correctly. You may not have anything left to fix. But it certainly needs to be inspected.

The key locates the flywheel in relation to the rest of the engine. In other words, it affects the timing. No wonder it won't run.

 

[ronsealdeath]

Re: 55 Evinrude problem, please help!

I suspected that it would have had some consequences but I wasn't 100% on how bad they were. Its pretty sobering to think that the crank and flywheel may be junk.

One question I have is when I get the flywheel off and get access to what is below it, what am I looking for in terms of signs of damage? Say the key is sheared, can I just use a key of the same size to re-fit? Just curious as to how I can tell if I have crank damage?

It will have to be a spares or repair motor/powerhead I think if there is major damage to the crank.

Thanks, fingers crossed
Al

 

[ronsealdeath]

Re: 55 Evinrude problem, please help!

OK I couldnt get the flywheel off so a puller is still on order. Just waiting for that to inspect the key/crank/flywheel.

Been thinking that if crank and flywheel ARE damaged then I'm going to struggle to find a spares repair motor that I can get the crank out of. Since found out my motor cant be 79 as it has the older, flatter flywheel if that makes sense? The guy who sold it to me must have given me a different model number? Anyway it looks like its a 1976 model or similar and in all honesty I havent seen many of them about.

I've seen a VRO 60hp mid 80s vintage for a good price. Gearbox fail but comes with a spare box ready to fit. Are these motors decent? Can I easily bypass the VRO? Just keeping it in mind if my 55 is going to become an anchor.

Cheers
Al

 

[bktheking]

Re: 55 Evinrude problem, please help!

If you couldn't get the flywheel off chances are it didn't move and no damage was done, when they do come loose and shear keys and damage cranks you can bet you don't need a puller to get it off as it's already "off".

 

[ronsealdeath]

Re: 55 Evinrude problem, please help!

There is hope! Having said that when the nut came off the flywheel was definitely loose then. I didnt pull the flywheel off as I was unsure if this would affect timing etc... I know now it wouldnt have but you live and learn.

I used loctite so suspect this is holding the flywheel on the crank to some degree.
We shall see.

 

[F_R]

Re: 55 Evinrude problem, please help!

Ouch. If you locktited the flywheel on, good luck getting it off.

 

[bktheking]

Re: 55 Evinrude problem, please help!

I hope is wasn't the super loctite or like F_R said, good luck getting it off.

 

[ronsealdeath]

Re: 55 Evinrude problem, please help!

It was the weaker stuff. I put too much of a blob on when i used it for the nut and some seeped onto the crank and flywheel seating. Shouldn't have done too much bonding, I hope. The flywheel nut came off ok so I'm hoping the puller will get it off.

 

[jtexas]

Re: 55 Evinrude problem, please help!

... Having said that when the nut came off the flywheel was definitely loose then. I didnt pull the flywheel off as I was unsure if this would affect timing etc... I know now it wouldnt have ...

generally speaking, flywheel key inspection is indicated any time you discover a loose flywheel nut, because of the likelihood that the key has sheared, which for sure will affect timing.

 

[ronsealdeath]

Re: 55 Evinrude problem, please help!

Thanks for all the advice on this problem so far. As mentioned previosly I thought the engine was a 55975C as this was what I was told when I bought it but on closer inspection the powerhead must be different to the leg as the ignition system appears to be 1975/76 on boats.net diagrams (Flatter flywheel)

Now I know these kind of questions get asked all the time so apologies for this but I have been offered a pretty good 55hp spares or repair motor that is a runner and quite tidy. Price is good and its easy for me to collect it. The guy said it is an early 80s 55 Evinrude. I'm going to need a spares engine for my 55 to try and sort whatever is wrong with it. So the question is what is interchangeable on the powerhead? From my investigations on part numbers it lookes like flywheel, crank and the whole ignition system are different to my 55. Should I just leave this 80s 55 alone or would it be worth a punt?

I'm not going to make a decision until i've pulled the flywheel anyway but just wondering?
Thanks for still reading my posts.
Al