1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

[GLPmike]

Hello,

Rebuild my starter, installed a new starter solenoid, new battery so I was finally able to do a compression test. Was able to get 110-115 psi out of all four cylinders.

Question: how good is this for this motor? Do I expect good performance?

Thanks,
Mike

 

[tashasdaddy]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

that age excellent!!!!!!!!!!!

 

[GLPmike]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

Thanks. I rebuilt the starter hoping I would get good results. Looks like it was worth it!

Now for the not so good news. I tried starting this puppy with acshot of starting fluid, but nothing.

Any ideas where I go from here?

Thanks again,
Mike

 

[kenmyfam]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

Thanks. I rebuilt the starter hoping I would get good results. Looks like it was worth it!

Now for the not so good news. I tried starting this puppy with acshot of starting fluid, but nothing.

Any ideas where I go from here?

Thanks again,
Mike

Start with the basics.
Compression (done and good)
Spark
Fuel delivery
Spark plug condition.

Post results and go from there.
Check out the "Top Secret Files" at the top of page 1 in this section for some really good info.

 

[ezmobee]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

And stop using starting fluid on your 2-stroke. It strips all the lubrication out of it! Use a squirt bottle with pre-mix in it if you have to.

 

[GLPmike]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

Thanks.

Forgot to mention that I did install new champion plugs. Also, cleaned spark plug wires at plug end only as well as the coil end. I did not do anything at the distributer cap end as of yet.

What is the easiest/safest way for me to check for a spark? Also, do I run the test on all four cylinders?

Mike

 

[GLPmike]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

Thanks for the fuel starter tip.

 

[kenmyfam]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

Thanks.

Forgot to mention that I did install new champion plugs. Also, cleaned spark plug wires at plug end only as well as the coil end. I did not do anything at the distributer cap end as of yet.

What is the easiest/safest way for me to check for a spark? Also, do I run the test on all four cylinders?

Mike

Spark tester available for around $10 from your local auto parts store. Yes check them all.

 

[GLPmike]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

Will do. Thanks.

What is a bigger problem? No spark or a potential fuel delivery problem?

Thanks again,
Mike

 

[kenmyfam]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

Will do. Thanks.

What is a bigger problem? No spark or a potential fuel delivery problem?

Thanks again,
Mike

Hard to say depending on what the root cause is.
Are the plugs getting wet when you crank it ??
Is this motor new to you ???

 

[lindy46]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

Will do. Thanks.

What is a bigger problem? No spark or a potential fuel delivery problem?

Thanks again,
Mike

Engine needs spark and fuel getting into the cylinders to run, so both are equally important. Without either one, the engine won't run.

 

[backyard mechanic]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

Spark tester available for around $10 from your local auto parts store. Yes check them all.[/QUOTE]


Put your new plugs into the spark plug boot, set it so that the metal body lays against the block... Turn it over and look for a spark. We even used screwdrivers, bolts, screws... anything to go from the wire to the ground and show a nice crisp BLUE spark. (Yellow isn't considered a good spark).

If you have 110-115 lbs of compression you shouldn't need a starter fluid boost. No need for the similar analogy of "towing this thing around for 6 blocks" while it pops wheezes and coughs. You know the type... rebuild the car motor and then drag the car around the block to get it started. WRONG WRONG WRONG!!!! Be a good mechanic and do it right.

Here's where you should be checking prior to the starter turning over for the "start up" (after Compression and lower end pressure checks to determine value/viability...)
Good fully charged battery. Electrical system checked, tight connections made up before and after you hook up to the motor.
Distributor pumping out good crisp BLUE spark at the new, carefully and uniformly gapped plugs? (Points set, dwell angle checked as well as point tension adjusted to the rubbing block?)
Coils checked for primary and secondary ohms, shorts/carbon trails to ground?
Plug/coil wires and boots in good condition, (not leaking power to ground somewhere)
Belt new/in good shape and set on the flywheel and distributor gear correctly? Arrows "pointed" at the right spots...
Carbs, hoses, FP cleaned and gas/oil mix correct?
Floats set for drop and max fuel? Check valves new or in good condition.
Idle jets new or in good condition, coarsely set to about 1 1/2 turns after seated LIGHTLY?
Did you get a look at the reeds? (Seems the reed block was right behind the carbs on those monsters). Look for chipped/broken reeds and that they are touching but not tight to the reed block.
Look for possible air/fuel leaks in gaskets etc.
Timing and synchronization all set up per spec?
General check/second check of all systems. Choke works as it should etc.
Gas hose attached, vent open, bulb tight and not leaking down.

Power up and start it up on the hose or in water.
After you get it running do your fine tuning/checking WOT timing.

I love it when they fire right up after a major rebuild or tune up.

 

[GLPmike]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

Thanks for the "checklist". Looks like I have my work cut out for me.

I will check for plug spark tomorrow and take it from there.

Thanks again for the input.
Mike

 

[kenmyfam]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

Spark should jump a 1/2" gap on the spark tester. Laying it against the head or block will show if you have a spark. The tester will let you know if it is good enough.

 

[GLPmike]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

Thanks. I plan on picking up a tester tomorrow and will give it a try in the evening.

 

[GLPmike]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

Will check the plugs tomorrow for wettnes.

I bought the 69 Glastron v156 with the motor and trailer last month for a "project".

This is the first power boat that I owned or worked on.

These boards are a lifesaver.

 

[kenmyfam]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

Good Luck. We look forward to your findings.

 

[jpriak]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

If you were getting spark that shot of starting fluid should have fired it up. I would get that spark tester and check for spark in all four and if they are all dead I would be looking at the distributor, wiring, on/off switch stuff like that..

 

[jpriak]

Re: 1968 Johnson 65 hp v4 Compression 110 psi - Good enough?

I don't know how to edit but thats not the flywheel it's the distributor . I was thinking a smaller motor. sorry I FIXED IT!!!!