Compression test

[tx1961whaler]

Re: Compression test

I did not see where he actually confirmed the spark of each cylinder.

 

[smokin_dodge]

Re: Compression test

I did not see where he actually confirmed the spark of each cylinder.

i havnt confirmed that there is a spark yet. what tool do you use to test the spark? i have gap checks but they are for 4 stroke lawnmower engines.

Status Update:

drained the oil out of the lower unit today and it was black goopy and had water in it. is it a bad thing to have water coming out of the lower unit?

 

[tx1961whaler]

Re: Compression test

Water in the Lower Unit is kind of bad.
I check the spark with a spark tester from the auto parts store. They're less than 10 bucks.
http://www.oreillyauto.com/EW3/Prod...d=1232328747362&cycleCount=1111&currentPage=0

 

[Solittle]

Re: Compression test

Water in the gearcase ain't good but don't panic just yet. Get it running then fill the gearcase with fresh oil as called for in the manual MAKING SURE THAT YOU USE NEW GASKETS FOR THE FILL & DRAIN PLUG. Then run it for a trip or two and recheck. The most common cause of water in the gearcase is when someone changes the oil and reuses the old gaskets. The gaskets are either a nylon gasket or an oring - chek your manual or match with what was on yours.

 

[smokin_dodge]

Re: Compression test

Now i was told that the motor was rebuilt top down 5 years ago as i stated earlier, but im still curious if i will need to replace the waterpump - mainly because it responded so well to the tcw-3 and it only had 200 hours on it before he put the boat up. im curious as to know what goes out on the waterpumps, do the gaskets dry up?

also going to do a carb rebuild. ive looked up the kit i need, its a 1979 Johnson 140 V4. part #'s 9-37100 for the Mallory & 18-7046 for the Sierra. Is there a difference in kits or are they the same.

Also, I still have yet to pick up a manual (the owner of the boat is trying to cut costs, leaving me to hunt on the internet) and ive yet to come across a carb breakdown to assist me in the carb rebuild.

ive rebuilt a few 4-stroke small engine carbs, but never a big carb like on the 140. am i looking at a morning job, or a weekend endeaver?

 

[gyoung]

Re: Compression test

(where should i ground the wires to, should i just attach them to a head bolt)

Just engage the kill switch. That will ground the ignition system so it can not be damaged while cranking with the plug wires off.

 

[tx1961whaler]

Re: Compression test

The rubber impeller gets hard, cracks, or loses its ability to spring back into shape. THe new impeller is cheap, and pretty easy to replace.

 

[tmcalavy]

Re: Compression test

Ground them to the power head.

 

[hamburgerman]

Re: Compression test

Do the impeller it can be costly if you dont, they should be replaced every two years or so, if motor has been run or not. Let me tell you I learned the hard way.

 

[jonesg]

Re: Compression test

You can rebuild the carbs, first time trying, in less than 2 hrs.
Look for the FAQ file here.

 

[tmcalavy]

Re: Compression test

Did I miss something...thought he asked about checking spark.

 

[smokin_dodge]

Re: Compression test

Status update: did a gap check today at 1/4" and got a bright blue spark. im feeling confident in this motor now. Im going to talk to the guy that rebuilt the motor tommorrow, see what he has to say about it.

right now the boat is sitting in a shop so its not possible to hook up a hose to the motor. so instead we thought of putting it in a 50 gallon trashcan. any problems with sticking a 140 in a trashcan when we fire it up?

 

[smokin_dodge]

Re: Compression test

update: pulled the started and took it to a local shop to have it tested, mechanic said it was good. so i put the started back on the motor. - Still having problems turning the motor. without plugs in the motor spins great, the water pump is circulating water - everything seems to be in good working order.

put the plugs back in and try to turn the motor, it will make 1 complete rpm before puttering out. so im thinking either the starter is dead ($220 or so) or could there be a deeper underlying problem with the engine?

 

[tx1961whaler]

Re: Compression test

I'd check all of the cables from the battery to the starter before buying anything. A voltmeter helps. I use a loooong wire to the negative battery terminal to the voltmeter (-) or COM, then measure the (+) battery voltage when cranking, then the voltage at the solenoid, then after the solenoid, then at the starter. I wouldn't think that any of those measurements should be under 10 volts when cranking.
You could try putting jumper cables directly to the starter stud, to see if it turns over better when hooked directly to the battery, but I do not know if this damages any electronics.

 

[smokin_dodge]

Re: Compression test

sorry forgot to add that, i hooked the battery cable directly to the starter motor and still would not turn the the engine over.

 

[tx1961whaler]

Re: Compression test

A good check, but if the battery cable was bad to begin with.....I'd use a set of car jumper cables to make sure, before putting 200 bucks into a starter, when it might be the cables.

 

[smokin_dodge]

Re: Compression test

A good check, but if the battery cable was bad to begin with.....I'd use a set of car jumper cables to make sure, before putting 200 bucks into a starter, when it might be the cables.

the first thing i did on the boat was replace the cable from the battery to the starter solenoid. thats the cable i used to hook up the battery directly to the starter. could it be possible for a new 4gauge cable to go bad?

 

[tx1961whaler]

Re: Compression test

the first thing i did on the boat was replace the cable from the battery to the starter solenoid. thats the cable i used to hook up the battery directly to the starter. could it be possible for a new 4gauge cable to go bad?

Not very likely. Looks like the starter needs to be rebuilt. Unless it's the ground cable/connection that's bad