gas fume going out cylinder when removing spark plug

[gabswiss]

gas fume coming out from cylinder when removing spark plug...normal?

I'm not mechanical savy so here is my question:

Is it normal that there is gas fume coming out of the cylinder when removing the spark plug? It only happens on one cylinder (on my 787 motor).

I'm asking that because I have problems with my challenger...spark plug keep fouling especially on one cylinder (same one where gas fumes comes out when removing spark plugs).


While I'm at it an other question: can i use a regular hose clamp to connect the fuel lines?

thanks!

 

[timmyboy76]

Whats the compression on the motor, and clamps..yeah, but, rust out eventually.

 

[gabswiss]

Whats the compression on the motor, and clamps..yeah, but, rust out eventually.

Compression test when I bought the boat (2months ago) showed 150 on both cylinder

 

[kustomkarl]

I would use stainless steel clamps so they won't corrode up.

Karl

 

[timmyboy76]

pull plug, leave cap on it, and hit button, see if theres spark.

 

[gabswiss]

pull plug, leave cap on it, and hit button, see if theres spark.

There is spark for sure.
There were gas fumes after leaving the boat on idle for 15minutes and then unplugged the spark plugs.(did that to read them to see if my low speed screw was adjusted correctly)

Boats run great but one spark plugs get fouled very quickly.
I also read the spark plugs after being at full throttle for 5 minutes and they looked good.
And the other day I had the same problem as the other guy in the other thread where suddenly I was not able to go past 15 mph (guess it was running on one cylinder? so I had to ride like that all the way to the boat ramp (like 10min. away).
Then when I looked at the park plugs, one (always on same cylinder) was extremely oil fouled (due of lack of ignition?? They were both good right before that)
All that happened at the same time I was out to do the full speed spark plug reading I mentioned above.

 

[timmyboy76]

make sure it aint oil, thats foul'n the plug. If the case, than the inner seal is leak'n...

Or, the needle in the n/s assy, is leak'n (carb)

 

[gabswiss]

make sure it aint oil, thats foul'n the plug. If the case, than the inner seal is leak'n...

Or, the needle in the n/s assy, is leak'n (carb)

Yes they are oil fouled (on one cylinder especially).
Carbs looks super clean...they have been rebuilt I guess right before I bought the boat. i took them appart and everything looks good.


P.S. Thanks A LOT for your help :cheers:


I added more infos on my post #6

 

[timmyboy76]

quote...Carbs looks super clean...they have been rebuilt I guess right before I bought the boat. i took them appart and everything looks good.

While yuo had it apart, you blast carb cleaner, to make sure?

 

[gabswiss]

quote...Carbs looks super clean...they have been rebuilt I guess right before I bought the boat. i took them appart and everything looks good.

While yuo had it apart, you blast carb cleaner, to make sure?

Going to do that. Was going to put them back on tonight.

What do you think about the problem I posted on post number 6 ?
Do you think it's related?
(To recap:
-I took the boat out to read the spark plug at full throttle. Result: both look great, not fouled
-Few minutes later on the way back, motor stop working proprely (can't get past 15mph, engine don't rev past ~4000rpm).
-Arriving at the boat ramp, it start working again good.
-I check the park plugs, one look like before and the other is totally fouled (probably because of no spark?)

 

[kustomkarl]

Check the wire connections of the coils. Then check to be sure one isn't bad and not delivering spark.

Karl

 

[gabswiss]

Check the wire connections of the coils. Then check to be sure one isn't bad and not delivering spark.

Karl

Ok will do that.

I disassembled the carbs yesterday and blasted carb cleaner but they already looked spotless.