1975 135HP Johnson won't start

[xfbeast]

Hi all,
I am new to outboards etc and have just brought a 75 135HP Johnson outboard.
The motor winds over but drains power quick from battery.
It won't start and I have checked spark etc and it looks like there is no spark on 2&4 but there is spark on 1&3.
I have cleaned terminals and changed the battery leads etc.
It is fitted with the flat spark plugs not the ones with the exposed electrode etc.
Any help or suggestions would be greatly appreciated.
Thanks
Cory

 

[F_R]

Re: 1975 135HP Johnson won't start

You are going to have to figure out what is wrong with that battery or starter. Begin with having the battery load tested. Many auto parts stores such as Advance will do it free. I hope it isn't a el-cheapo battery with no capacity.

If the battery is ok, it is on to some voltage drop tests on the cables. And/or inspect the starter. The field magnets may be shattered or brushes worn out. Can we assume the engine itself turns over with no binding or difficulty with the plugs out?

That motor needs to be turning over at least 200 RPM to have spark. I suspect that is your spark problem.

Personally, I would replace those plugs with Champion L77JC4 or QL77JC4.

 

[emdsapmgr]

Re: 1975 135HP Johnson won't start

After you complete the tasks FR has recommended, you may want to do some ignition troubleshooting. There is an exellent website: cdielectronics.com. The troubleshooting for your engine starts on page 35. It's a great reference.

 

[xfbeast]

Re: 1975 135HP Johnson won't start

Ok update time.

So I went through and tested everything and put my battery on charge to make sure it was fully charged etc.
I got the motor to start and run but I noticed when I was doing my checks that the previous owner has put 2 wrong plugs in it and I'm guessing that's why it was running a little rough not too bad though.
I have ordered 4 new plugs L77JC4's and hopefully that will help make it run a bit smoother.
I also took my boat out on the water yesterday and it ran ok when idling up but when I put it into gear it would back-fire and cut out most of the time.
I managed to get it out for a bit of a run in the harbour and it ran fine but didn't feel like it was opening right up or wasn't giving full power out there? (Could this be from the mismatched plugs?)

Next the previous owner has put a whale tail on the motor as in photo. Does this look like it would help or hinder on a 16ft glass boat?



Thanks for the help so far and thank you for any help/advice that is to come.

 

[mark1961]

Re: 1975 135HP Johnson won't start

That motor should have Champion UL77V or L16V (surface gap) plugs fitted.....the L77JC4's are the same heat range and should be okay, check for piston clearance first though.

 

[boobie]

Re: 1975 135HP Johnson won't start

Piston clearance is the big thing on that mtr between the "J gap" plugs and the "surface gap" plugs.

 

[emdsapmgr]

Re: 1975 135HP Johnson won't start

The whale tail is usually a hopeful solution for some other problem. Get the right pitch prop on the boat and make sure the engine setup is correct. Many of these whale tails are mounted such that they actually drag in the water-when on plane, causing extra spray. That can cut down on top speed and fuel economy. Ilve seen many of these hanging on boathouse walls after their owners decided to take them off.

 

[xfbeast]

Re: 1975 135HP Johnson won't start

Ok thanks for the tips.
I checked and replaced the plugs with a set of L77JC4's (Funny thing is or isn't Mark1961 it had 2 UL77V plugs in the top cylinders and 2 L16V plugs in the bottom cylinders?)
I took it down to the boat ramp for a run and it started not too bad and ran up on the start lever ok but when I drop the revs it cuts out a lot of the time or when I put it into gear it chokes and dies unless I gun it.
I've read a bit in other threads about the link & sync? How do i check if it is set correctly?

 

[xfbeast]

Re: 1975 135HP Johnson won't start

Thanks i plan to take it off and run the boat without it because it definately lacked power and didnt plane properly.
How do i check the prop pitch?
And what do you mean by engine set up.
I also noticed that it's not pumping alot of water but when i checked the water pipes going into the motor there was plenty of water.

 

[emdsapmgr]

Re: 1975 135HP Johnson won't start

Engine setup is making sure the engine is mounted on the transom at the correct height. There are holes in your aengine's transom brackets which will permit the engine to be mounted slightly higher/lower. You want the engine set at exactly the correct height for optimum performance and fuel economy. If the engine does not idle well, you could have a couple of issues. The idle timing may not be set properly, causing low idle rpm's. The engine will repeatedly die if it is set too low. Should be 650-700 rpm's, set when the boat is floating normally in the lake, the engine is running in forward gear. Also possible that your carb idle passages may have some residual debris (dried fuel) in the, which will really affect engine idling. They are pretty small and have a huge effect on even idling. Check the prop by running the engine at WOT. The correct prop will permit that engine to rev to 5500-5800 rpm's with just you in the boat. (and fully trimmed out-if that engine has power trim...) If it runs at a different rpm, then you should consider changing to another pitch prop. Different pitch props can change the WOT rpm's as much as 300 (or more) rpm. You can check the temps of each head with a laser temp gun. I believe the vernatherm (thermostat) on that engine runs cooler than later models: Should be 115-125 degrees normally.