1976 Johnson 135HP V4

[FishRFood22]

Hey guys. So I've been doing a bit of reading on here about these motors and it seems they are pretty bulletproof and nice old motors. A couple of months ago I purchased a 1976 Aquasport 19-6" FF powered with the original Johnson 135HP V4. I've had it run on muffs a couple of times and had it on the water twice. It is ALWAYS hard to start. Just gotta dump starting fluid into the carbs and crank until she decides to start. After its started it runs great and was mighty quick at WOT. The 2nd time I had it on the water I was cruising around 35mph and it just died out (not like a rough running/choppy die out, like a drained battery die out). I chalked this up to the stator going bad and not charging the battery while I was running it. I hooked the battery up to a charger and tried to start it (with starting fluid) for about 15-20 mins in the driveway on muffs. It cranks and cranks and cranks but wouldn't start (fuel ball stays hard). I replaced the stator and replaced spark plugs. Still can't get it to start. I have the ignition coils ordered, just waiting on them to get here. Also sprayed the carbs up with some cleaner. Are there any other avenues I should be taking? I will be installing the new ignition coils with caps and springs as soon as they arrive. If this doesn't work, should I do a carb rebuild? What else would make it so hard to start, but yet run fine after starting? Also, why are there no magnets under my flywheel? Are they internal? Thanks in advance for the help and info, I'm sure I will get plenty from this site!

[fitz73222]

STOP USING STARTING FLUID TO START THIS ENGINE. Starting fluid will wash off the premix oil on the crankshaft and bearings. Continued use will destroy this engine. It has a mechanical choke, is the choke plunger working that closes the choke butterfly in the front of the carbs? Take the air silencer cover off and make sure the choke is working.  Stop throwing parts at a problem that you don't understand but it's your money.

[RickK]

Good to see you back Farley. We hope you check in more often for the motor questions.

[Capt. Bob]

Two flags here.

Hard starting but runs good after starting.
Died while running.

If those were two hints given to me, I would have first guessed; fuel flow.

To confirm my guess, I would have pulled the plugs after the long crank/no start and looked to see if they were wet.

If you must use a "starter fluid" it is much wiser to pull a plug or two and squeeze in some premix but that really isn't necessary with a working choke. Fact is, sometimes one uses too much choke.

Good luck.

[FishRFood22]

Choke is functioning just as it should. checked plugs for spark, they are working fine. took all 4 plugs out and squirted a bit of premix into each cylinder, reinstalled, tried to start, still nothing. Cranks all day long but won't fire now, and it was hard to get it started on most occasions before it went out completely. Could this be a real dirty carb?

[fitz73222]

It's possible it's not reaching at least 300 rpm at cranking speed. We had a perfect running 115 that would not start with the starter with the plugs in. It sounded like it was turning over fine but it wasn't reaching cranking speed. Wrap a rope around the flywheel and the engine would start instantly. It could either be a weak battery or troubled starter. The engine does not need the battery to run, just to turn the engine over to start. The flywheel has hooks cast in it to start it with 1/4" rope. Make something up the handle and couple of feet of rope and see if she starts, make sure the keyswitch is in the on position. No BS here I have actually done this, I'll never forget this because it took us two days to figure it out! It was a bad starter.

[Capt. Bob]

Been there , done that with my V-4 Johnson. They (OMC) use to supply a pull rope in a plastic bag, affixed inside the cowling.

I found that if one person pulled and the other turned the key to crank, it worked rather well.

As Fitz stated, you need at least 300 rpm to light those engines off. I think you would be rather surprised at how fast that flywheel has to spin to reach that rpm.

Good luck.

[FishRFood22]

Thank you guys for the help/advice. I did a compression check earlier today before I read your suggestions and the cylinders measured 90,60,15,90. So I think I found my problem.. Not what I was hoping for.

[Capt. Bob]

Ouch

[fitz73222]

Yes, those are dismall numbers for sure, but the engines were notorious from having carbon problems and severely stuck rings. I worked at an  Evinrude dealer in those days and some of those engines didn't make 4 years without being totally carboned up or blown up with broken rings. We used to keep several replacement powerheads in stock for this reason. Pull the cylinder heads and have a look. They were wonderful engines and I loved the one we had.

[FishRFood22]

I decided to go ahead and re-power the vessel. Got a nice deal on a 94 Merc 125hp. Came with controls and a 4-blade. I haven't torn into the old Johnson yet. Before I do, is anyone interested in it? I'm sure someone may find use in keeping it around for a parts motor.