Cylinder #4 issue

[LaTriton]

250 PRO XS Serial number 1B839289
i checked condition of my plugs last week and notice cyl. 4 plug is very black. I swapped the plug and the coil from cyl 2 and 4. After fishing today, pulled cyl. 2 and 4 and cylinder 4 is still producing a sooted plug and the plug and coil swapped from 4 to 2 look good. So coil and plug is good. Yellow49BD3758-AB1A-457C-AF5E-BF6965B1B701.jpeg box shows the plug in question. Is this an injector problem? Thanks for the help.

[lpugh]

Possibly, Check availble voltage with a KV tester, should bridge a .625 gap before misfiring, Mist the plug wire and coil check for spark leakage. Inspect that coil carefully for cracks and or whitish material that looks like it oozed out of the coil

[LaTriton]

Thanks for the response Leon. As I stated in my post, I swapped the coil and plug from cylinder 4 to cylinder 2 and the problem remained at cyl. 4. It did change the results.
‘appreciate it.

[JOE54]

compression on #4, reed inspection ,sleeve inspection , fuel air psi test will show a leaking injector

[EuropeanAM]

compression on #4, reed inspection ,sleeve inspection , fuel air psi test will show a leaking injector

^^^^^

[LaTriton]

Joe/Don, could this due to bad tracker valve? I noticed yesterday that I have coming fuelout of Schafer valve on port rail.Thank you

[JOE54]

while not impossible but all cyls should be rich , would inspect tracker first ,but any air leak /stuck open direct inj can cause that also

[EuropeanAM]

Problem is most likely on the port side, as Joe is suggesting. Injector, air leak, injector o-rings, fuel pressure regulator, etc.

[LaTriton]

I have been using the search function and see that people have put compressed air into the the Schrader valve to locate air leaks. Do I put air in the starboard side, port side or both? If so how much pressure and could I use soapy water to spray to locate the area of the leak? Thank you gentlemen

[JOE54]

port /air only ,leak is likely internal soap may not show it , fuel air psi test is needed first to determine if you have a leak at all with correct gages

[LaTriton]

thank you Joe, I am working on getting some glycerin filled gauges.

[JOE54]

[FishingKY]

compression on #4, reed inspection ,sleeve inspection , fuel air psi test will show a leaking injector

Joe, what is meant when you say a sleeve inspection.

[JOE54]

for rotation /spun

[apdriver]

If you want to see pictorial check this thread out. Kept these master techs busy and up late.

https://www.bbcboards.net/showthread...Rotated+sleeve

[JOE54]

whyd you have to bring that up , i thought we were tight ,