94 GTX compression...

[seadoodave1]

was getting 150 out of both cylinders...re-built carbs, change oil lines(were broken) replaced fuel selector valve...and sounded GREAT(out of water). Put in the water for 1st time since work done..and seemed to be Ok..for a minute...top end was great, then started boggin, re-start, etc same thing, good top end, then DIED, totally. didn't seem like was gettin spark to ignite(new battery) plugs...any, got towed in and checked compression...one cyl 150. the other 60..seems like and ignnition or timing thing, but dont know how I could have damaged cylinder, as it was 150, before I put in the water.

Any ideas?

 

[seadoodave1]

Is the engine "done"? as mentioned, 150 in one cyl...65 in other...also could it be a timing issue? Dumbfounded!?!

 

[manolocross]

You said you changed the oil lines...did you Bleed and prime the oil lines before you started the engine again after all this maintenance???

 

[seadoodave1]

No i didnt, BUT was told it was ready to put in the water and ROLL. The one cylndr with low compression and a VERY ugly plug, when I took it out. Like a grey/silver deposit/buildup...and plug were brand new. As mentioned, sounded great out of water.

 

[brandon32689]

Make sure your battery is full and you are giving full throttle while you check compression. Also dp it a couple times on each plugs to make sure. If you still just have 60 you will need some work done. What caused it idk. You may want to pull heads and look at cylinder. See if the piston is burnt on top.

 

[LouDoo]

Like Brandon said, if you're sure the compression reading is accurate, you need to pull the head and see whats going on.

Lou

 

[seadoodave1]

Thanks to both of you...workin really hard to get this thing right... and now this. Oh well, learning ALOT from you guys

 

[brandon32689]

Ya pull the head and shoot a few pics post them up and someone will tell you what happen. If you catch it early and nothing locked up a simple top end rebiuld will fix.

 

[seadoodave1]

yeah, nothing locked up, as far as I can tell. Will get pics...and thanks!

 

[brandon32689]

Okay cool then just post em up.

 

[Bills86e]

Look in your water separator/filter, if you have water in there, you have more in the gas tank, and is culpret. A single droplet of water in a carb can stop the flow of fuel thru a carb, as its ten times the size of a gasoline droplet, and cause a lean burn in that cylinder's piston top.
Water being heavier than fuel gets pulled into the bafel thru its lower screen and circulates and re-circulates.

 

[seadoodave1]

Ok..what would cause low compression in one cyldr...1@150/ other @ 65?

 

[Bills86e]

The beeper should have sounded, the motor would have been very hot, maybe 1000* in the non-fireing cylinder. With ignition on, just ground the wire on the sensor that is between the two *plugs. Either the sensor or your beeper isn't working. The sensor operates at about 207*.
Then it contacts and signals.

 

[Dr Honda]

The silver on the plug is melted piston.


The engine could have melted down because of:

1) lack of oil. (if it wasn't bleed)
2) Lack of cooling
3) A crank seal leak.
4) crank was out of index.

 

[seadoodave1]

Hey ...thanks again to the great people on this site...having top end re-built, one piston/sleeve replace, and carbs totally rebuilt..Thanks!!!