1980 Evinrude 35hp 2cyl running problems

[liki]

I have 2 problems with an old 2cyl Evinrude that are likely related. Otherwise the engine starts and runs very reliable and nice, but there are 2 issues.

First, especially when then engine is cold I assume that it misses an ignition every now and then. The effect is very similar to hitting the bottom fin slightly into a rock. That is, the engine jumps a bit and "hiccups."

The second problem is that seldom the engine just refuses to start after running and then resting a bit. It seems to give a spark, fuel flow is evident from exhaust and starter turns the engine but no promise, nothing. Until after enough tries it just starts like there were nothing wrong.

I was suspecting an electric problem, like an intermittent grounding in ignition spool or faulty grounding as there was once suspicious connector and fiddling it "fixed" the problem the last time. Alas, it turned out to be that that wire was for the starter relay. These engines are dead simple, but a thread about a misfiring mariner made me fear that this evinrude is also in need of a total rebuild. Any ideas about it, advice, or knowledge about common problems in these?

[pistnbroke]

over fueled when starting ..plugs wet ,,,,put your question on the evinrude part of the iboats.com forum.

[powerabout]

hiccup when cold is too lean and also possibly why you have hard starting.
what happens if you choke it?

[thudpucker]

I had one of those for years. I had to pull the rope though.
To clear up an old possible issue, look for a Mercury switch on one of the cylinders.
It's job was to cut the RPM's down if you jumped a log. Tipping the engine up, that Switch grounded the points for that cylinder. Yes, I took it off my engine.

Second thing on the "Jump" you experience mignt be the Clutch Dog down in the Lower Unit. It's slipping out of contact with the Drive gear. It feels like you jumped a log or hit a rock at speed, but bangs right back into gear again.

When I saw how badly worn that gearworks down there was, and that it was still working, I was greatly in respect for the OMC Lower unit engineering.
You can either buy new gears or take yours to a machine shop for re-surfacing.

That third problem of 'not starting at all' is likely a bad ground, or a bad wire connection at a switch. Those old OMC's had good paint, but nothing can keep the Corrosion from mariching right up the metal and under the connectors.

My engine was a direlect I bought off the Beach and 'fixed' up. The Natives had used it to death and left it laying.
The only other 'strange' problem I had with that engine was 'miss' at certain RPM's and some pretty bad vibrations at other RPM's.
It was the Upper main bearing worn plumb out. They'd not been using good oil in the gas.
Other than that, your motor ought to outlast your grandChildren.

[powerabout]

there is no mercury switch on a OMC as standard

[pistnbroke]

the mercury switch was to stop it being run tilted when being flushed as a kid walked into the propeller once and was killed ...
Check if plugs are wet or dry when it wont start ....all other stuff suggested good ....did you try www.iboat.com they have sections for each brand of engine and whilst you get the usual tossers much of the advice is very good ...there are no tossers on BD.net ....please note !!!

[liki]

Originally Posted by thudpucker

Second thing on the "Jump" you experience mignt be the Clutch Dog down in the Lower Unit. It's slipping out of contact with the Drive gear. It feels like you jumped a log or hit a rock at speed, but bangs right back into gear again.

In fact the shift lever sometimes acts suspiciously and feels stuck when trying to disengage. Could be the time to disassemble the lower unit the next winter.

[powerabout]

Originally Posted by pistnbroke

the mercury switch was to stop it being run tilted when being flushed as a kid walked into the propeller once and was killed ...

Are you describing liki's engines history??

[liki]

Did some more troubleshooting yesterday, a gear problem seems very probable. With forward engaged at idle had a jump about once a minute, at around hull speed every 30 seconds and at slow plane already every 5 seconds or more frequently. Observing more carefully this time, I think that the engine itself ran fine all the time.
Time to investigate is there any play in the gear control or adjustments that could help to keep the outboard usable over this summer... But I already did some parts sourcing and gear parts for this outboard didn't seem easy to find and original OMC/BRP rear gear was 3 times more expensive than forward one and pretty expensive.

[powerabout]

if its jumping more than likely you will see the lever on the side of the engine also move when it jumps?
how does the oil in gearbox look?
The adapter that you undo to remove the gearbox down low on the stb side of the gearcase can be loose so you lose travel there so never engage properly.
Your shift could also be inside the water intake screen where it came apart on later engines this is fool prof so shouldnt come loose????
Problem is once it jumps it has started to do permanent damage.

The lever on the side of the engine has adjustment where it bolts up to the shift cross shaft in the top of the exhaust housing, the adjustment here is critical to longevity of the gears/dog/and cradle.

As I remember there was also several upgrades to the original parts to make them much more durable.I think the set up was changes from a 2 lug dog to 3 log so hence new gears in the kit as well.
Ask a dealer to look up the service bulletins for that engine before you buy any aftermarket parts as maybe there still is a kit?

[liki]

Gearbox oil was just changed, the old oil certainly had no water in it and seemed pretty good though it likely wasn't very old either. During first trips we noticed this same symptom infrequently but now it is prohibitive for use. While testing I held on to the gear lever outside of the engine case but felt certainly no movement there.
I'll have to study how the gear linkage acts with the long lever on the side of the power head and check that it moves all the way to engage gear. If that does not help I think it is time to disassemble the gear box and see what needs to be renewed there.
Alas, I didn't find any gear set for this engine from OMC/BRP or aftermarket manufacturers but atleast all the parts should be available.

[powerabout]

make sure if you are buying new that if there is the possibility to move to 3 lug set up you do that instead of just replacing the original

[liki]

That could make sense especially if the rear gear is also to be replaced ... but cost for that part alone was ~400 USD while forward and pinion gear and shift dog were priced at 100-200 USD each. Too bad that there seemed to be no aftermarket sets.
I just checked BRP spare parts catalog illustrations and it seemed that long vertical level coupled with the shift lever has the adjustments in its top end and it has no other purpose but the vertical shift rod is coupled into the shift lever in the lower engine body?

[powerabout]

There is no update kits on the brp web site you will need a dealer to make the enquiry/look in the service bulletins
Sierra has a kit for 84 yr+ I guess you just need to find out if they fit?
Trip to outboard salvage yard might be the go as you might find freeze damaged housing but good parts

Re adjustment from brp web site, item 39 is slotted to item 42 the shift lever so it can adjust.
on the crankcase page the long shift interlock lever item 42 determines how far the shift lever can travel so hence if it is not far enough you rotate the shift cross shaft further into forward.
NB make sure there is not too much load (any)into forward, you can feel this by turning the propshaft as you drop it into gear and see if there is any extra drag. If there is you will just wear out the shift cradle and be out of travel.

The fitting under the powerhead on the end of the cross shaft could have come lose as well. If you remove the lower unit and hold the shaft then move the shift lever you will see if there is any freeplay.

[thudpucker]

LIKI, is it fixed? What was the problem?
Did you dissasemble the lower unit and turn all the gears around so the problem went from Fwd to Rev? :/)