96 johnson 150

[Chuck4741444]

problem: rough idle \ runner good at wot 21 ft. CC running 32 mph that's what it was before rebuild
Things I've done.
1. tested the coils
2. test resistance on plug wires
3. tested resistance on plugs
4. tested plugs for blue spark.
5. set the timing @ 6 btc per manual.
6. removed 6 carbs and throttle.7. cleaned and wired every hole. (Twice)
check reeds buy looking for light shining through them ( replace 2 that were not closing tight)
7. set mixture screws at 5 turns per manual. turning in only effect 2 carbs.
8. reinstalled them.
9. Motor fires right up when its warm.
10. I have pulled the plug wires one at a time. 3 of them does not change the performance,
11. I can cover and flood that card and nothing changes. full pours out when I remove my hand.
12. sprayed carb and chock cleaner around throttle plate, carbs nothing changes.

Is it possible that I have 3 bad plugs? their fairly new.
or could it be reeds" I don't have fuel spraying form the carb, as before.
is there any way to check the reeds without removing the again?
thanks for any help.

 

[saltchuckmatt]

Plastic carbs parts .... Assuming compression numbers check out.

"Blue spark" but how far do they jump?

 

[Chuck4741444]

Plastic carbs parts .... Assuming compression numbers check out.

"Blue spark" but how far do they jump?

compression is 100 +- 5 psi, I heard the were low compression motors, I just put new plugs in, I think is being flooded with fuel, or the power pack is week, the idle screws on half the carbs has no effect on it. I started pulling plug wires, its running on 3 cylinders. I have a spark tester, the type in a plastic housing, will it do? I've seen the clip-on type, after all the money I've spent, before I tell my wife, I'll run it like it is the rest of this season. lol

 

[saltchuckmatt]

"low compression motor" ?

End of life is coming, rest is BS.

Running in a barrel or muffs you won't see much difference. If you have no spark it could be a power pack but weak spark more likely coils.

You need a spark jump tester....pick up one of these cheapies and look for a "zap" of 7/16, nice and blue.

As for the wife, we all have our secret ways!

 

[Chuck4741444]

Plastic carbs parts .... Assuming compression numbers check out.

"Blue spark" but how far do they jump?

I pull the plug wires one at a time while running, it sparks from inside the cup to 3/4 to an inch out to a head bolt,
but when I pull a plug and with wire connected to the plug, the spark is week, barely jumps to ground at a 1/16 or less. the plugs seem to be the problem ngk bpr7hs 6422

 

[saltchuckmatt]

Well I run champions and haven't really liked the ngk's but guys on here like them and I doubt that's your problem. Never hurts to try though....cheap test.

 

[Faztbullet]

If you use NGK the correct ones are BPZ8HS-10 and Champion is QL78YC. Which 3 plugs are not firing as motor has a ignition cutout switch?

 

[Chuck4741444]

runn

"low compression motor" ?

End of life is coming, rest is BS.

Running in a barrel or muffs you won't see much difference. If you have no spark it could be a power pack but weak spark more likely coils.

You need a spark jump tester....pick up one of these cheapies and look for a "zap" of 7/16, nice and blue.

As for the wife, we all have our secret ways!

Running in a Barrell. strong spark about an inch. week spark on the back side of the plug, real week,
I must have the wrong plugs ,nkg bpr7hs.
the manual says that it could be fuel leak through the primer solenoid. that make scene, the electric primer stopped working, it may be stuck, I can't get the rpms below 1100.
I'm going fishing tomorrow, even if I have to drifted fish.

thank for your input.

 

[Chuck4741444]

runn

Running in a Barrell. strong spark about an inch. week spark on the back side of the plug, real week,
I must have the wrong plugs ,nkg bpr7hs.
the manual says that it could be fuel leak through the primer solenoid. that make scene, the electric primer stopped working, it may be stuck, I can't get the rpms below 1100.
I'm going fishing tomorrow, even if I have to drifted fis

runn

Running in a Barrell. strong spark on all 6 cylinders, I went through the fuel system last night, double checked the timing, started it up this morning, it's still missing on 3 cylinders, could the power pack not be firing on these cylinders at the proper time. I can turn 3 of the 6 idle mixtures screws all the way in, and nothing changes. I'm all most convinced it's in the power pack,

 

[racerone]

Have you checked the shift switch ???----An item found on the MOTOR linkages.----Shuts off spark to 3 cylinders during shifting.----If it is sticky ???

 

[Chuck4741444]

If you use NGK the correct ones are BPZ8HS-10 and Champion is QL78YC. Which 3 plugs are not firing as motor has a ignition cutout switch?

Have you checked the shift switch ???----An item found on the MOTOR linkages.----Shuts off spark to 3 cylinders during shifting.----If it is sticky ???

its running on cylinders 2,3,4

 

[Chuck4741444]

Have you checked the shift switch ???----An item found on the MOTOR linkages.----Shuts off spark to 3 cylinders during shifting.----If it is sticky ???

i have pulled the plug wires off, its running on 2 cylinders, #3 an #2 the other 4 don't change with them on or off. but all 6 wires are firing good.

 

[saltchuckmatt]

i have pulled the plug wires off, its running on 2 cylinders, #3 an #2 the other 4 don't change with them on or off. but all 6 wires are firing good.

You had better re-explain. Doesn't make sense....at least to me.

 

[Chuck4741444]

You had better re-explain. Doesn't make sense....at least to me.

I pulled each plug wire, one at a time, cylinders #1,4,5, and 6 are dead. its barley running on #2 and #3..

When i check the spark on the dead cylinders, the plugs are firing to ground, with a spark about 3/4 inch and blue in color.

 

[saltchuckmatt]

I pulled each plug wire, one at a time, cylinders #1,4,5, and 6 are dead. its barley running on #2 and #3..

When i check the spark on the dead cylinders, the plugs are firing to ground, with a spark about 3/4 inch and blue in color.

Then you have a fuel issue most likely. This assumes your coils are properly hooked up to the right firing order.

 

[Chuck4741444]

its running on cylinders 2 and 3

The switch is missing, could this be my problem

 

[Chuck4741444]

Then you have a fuel issue most likely. This assumes your coils are properly hooked up to the right firing order.

have been through the fuel system, twice, i have wired every whole in the throttle plate, and carbs, check flat levels, blew air through every thing,

 

[saltchuckmatt]

Switch shuts down one side....so your answers are inconsistent with what is happening.

Try a different compression gauge.

Might want to inspect piston skirts. Remove exhaust covers.

Compression
Spark
Fuel

Did you check the firing order?

Reading back you state "rebuilt the motor" your getting 100 to 105 on a rebuilt power head?

 

[racerone]

???----These motors have hole in the cylinder wall.-----Bleeds off a bit of compression at cranking speeds.-----So 105 might be normal on one of these.

 

[saltchuckmatt]

I've heard of the lower compression commercial motors....rebuilt one at 105?

Id question that but thanks for educating me.