My Promax is becoming a real headache

[Ocktane]

So ya'll know I sold the XTB and bought a 2003 from a fella down in Atlanta back in the fall. Bought it with a blown 150 Promax. When i bought it I was told it had a stuck cylinder. Took it to Dennis Hoffman down the road here and tore it down for rebuild. Found a couple scuffed cylinders (#3 and #5)and pieces of water pump in the passages, looked simply like a overheated motor.

Rebuilt, broke in and checked burn on the plugs. #5 showed no burn and clean, oily gas on the plug. We checked voltages and there seemed to be erratic output from the stator. Changed out the stator and ran it. Pop goes the weasel, #5 went down again.

Had the motor rebuilt again; Dennis stands behind his rebuilds and he took care of me. Resleeved #5 and put in a new piston. Ran on the hose and still found less than desirable electric output. All signs pointed to a major misfire so installed two new switch boxes. Also changed out a few coil packs that were falling apart. Also found a wire partially burnt up that was fixed.

Motor seemed to be running like a champion, checked fire on all 6 and was good to go so I started breaking her in again. Now, 6.5 hrs into break in and heres what I'm showing:

That's #5 plug,

compared to all others that look like this:

I'm taking back to the shop tomorrow after i get off work to try and dig deeper and figure this out. This motor has had a demon in it for awhile (the guy I bought it from Johns04Hoe had issues with it running poorly per his old posts). Anyhow, just curious what everyone thought... sorry about the NOVEL I wrote here, just wanted to post what I know. Appreciate anyone's input. The damn bass spawn is here and I'm without a reliable motor and its driving me NUTS!!!! :banghead Thanks everyone. BTW if anyone in West TN needs a backseat bass fisherman this weekend or next, gimme a hollar!!

 

[Ocktane]

Brian you were right... I regret selling the old Promax. Mike West you have a GEM on the back of that XTB!!!

 

[skewby]

could be water gettin in that cylinder

 

[silverbullet02]

I can stick a piston in my spare 225 and bring it out next weekend if you want. Or I could just bring my boat out that way.

Skewby, your phone work?

 

[msharp]

Did you have the injectors cleaned and checked for proper flow ? I would pull them out and send them to Glenn's for a check up . ECU also could be going south . Have seen a few that show's pulse width increasing when it actually was not. If you know someone that would let you run thier ECU and then read your plugs .

 

[rmills280]

i made the post on skewby's computer, has the head ever been repaired? thats the reason i suggested water i had one that was repaired and the same cylinder kept going so del eaves took a close look and the head had a pin hole in it letting in just enough to let it run for awhile.

 

[xb03]

Check injectors, and index your flywheel with each cyclinder and check wot timing on each cyclinder. Make sure both switch boxes have the same part #.