Evinrude 50hp 3-cylinder fourstroke with timing chain / valve timing

Hi

I have got 3-cylinder Evinrude 50hp 4-stroke engine from around 2000 model year. Lower end was replaced by earlier owner after collision to a rock etc. However, engine did not start after repair.

I checked there is continuous spark and and injectors are supplying fuel to all cylinders as long as engine is cranked. Engine occassionally bangs to exhaust, but doesn't start running.

Compression pressure is only 5,5 bar evenly on all cylinders. However, when testing with compressed air, there seems to be no leakage from valves when they are closed, and piston rings neither leak pressure abnormally. I think the valve timing may be incorrectly adjusted.

The engine has timing chain under engine, so it's harder job to disassemble completely.

I see that the cam sprockets have a "top" marking and arrow, and they are facing upwards at the same time. Should some of the cylinders be at TDC at the same time, or how to determine if the timing is correct or even close to correct setting?

Thanks for advise in advance.

-Vili

Re: Evinrude 50hp 3-cylinder fourstroke with timing chain / valve timing

You go off the TDC of #1 cylinder. I would get the manual to make sure that you are absolutely sure the engine is timed correctly. I would concur that the engine may have slipped a tooth with the impact on the engine. The backfiring would be an indication that the timing is off.

Re: Evinrude 50hp 3-cylinder fourstroke with timing chain / valve timing

5.5 bar is equal to 80 psi. That is way too low for a four stroke. I would expect to see at least 100 PSI more, but I don't have the spec. The big sister to this engine, the 70hp 4 stroke pushes 180-205 psi which is much higher than your 5.5 bar. Again, this indicates cam/valve timing is off, to me. Be very careful at this point...you could ding a valve/piston.

Re: Evinrude 50hp 3-cylinder fourstroke with timing chain / valve timing

out of curiosity the 4 stroke is it not a Suzuki dressed in Evinrude clothes . I have found this out reading a forum on the net

Re: Evinrude 50hp 3-cylinder fourstroke with timing chain / valve timing

Yes, a wolf in sheeps clothing. LOL

Re: Evinrude 50hp 3-cylinder fourstroke with timing chain / valve timing

That 3 cyl Evinrude 4-stroke is a Suzuki engine.

One problem they have after a good underwater impact is that the pressed on crankshaft gear slips position and the valve timing is off. On that engine the powerhead has to be removed to access the timing gears and chain. Chances are it will need a new crankshaft which may make it uneconomical to repair.

Re: Evinrude 50hp 3-cylinder fourstroke with timing chain / valve timing

Thanks for the advise to concentrate on the timing.

Because of not having the the manual I tried to go to basics and turned engine and checked cam lobes. It seemed that the timing between cams was 180? degrees shifted (exhaust opened after intake). So I set the timing by primarily concentrating that when 1. in tdc the intake is opening and exhaust closing. But also in that situation both cam gears' "up" arrow is facing up.

Can't understand how that was the alignment also earlier. I thought the the sprockets can be only in one position related to the cam (rigid on exhaust / 3 screws and pin on intake cam)

But now the engine started. Measured compression before start (cold engine) was about 8 bar. I hope anything is not going to slip when I test it next time.

Video of the machine's short test run on dry land: Evinrude 50 fourstroke running - YouTube

Can it be safely run longer on the stand with "ear muffs" and garden hose connected to the lower end?

-Vili

Re: Evinrude 50hp 3-cylinder fourstroke with timing chain / valve timing

That engine is hitting the rev limiter, I think. If you are in neutral, and you manually attempt to accelerate the engine RPM, the rev limiter will kick in at around 2500 and it sounds exactly like your video. The EMM will not allow higher revs than 2500 when the engine is in neutral.

Re: Evinrude 50hp 3-cylinder fourstroke with timing chain / valve timing

Check this out. Read description, see pics of prop. Interesting. 1999 Evinrude Four Stroke 50 Horsepower Outboard Engine | eBay

Re: Evinrude 50hp 3-cylinder fourstroke with timing chain / valve timing

There was no water coming out in your video so check up on that too, you dont want to burn up your impeller

Re: Evinrude 50hp 3-cylinder fourstroke with timing chain / valve timing

Two days ago ran it a bit longer with a water barrel. It was spraying water out, so hopefully it was not broken yet to water shortage. Also the revs could be raised by moving the shift lever on engine side out from neutral.

If the timing has gone off from crankshaft side, will it eventually happen again, or is it even possible to correct the timing and run engine after such happens?

Now the only problem is continuous warning tone, and red light on the rev counter with (!) symbol. I had rectifier disconnected because erlier I followed an ignition troubleshooting guide and that was the step 1. With rectifier connected, the charging voltage was up to 17 volts and alarm signal was on. Could that indicate problem with charging system? I read that in some (older?) systems the voltage can be high if there is no external load.

When ignition is swithced on, there is only one beep after some seconds, doesn't it mean no faults detected.