Found it
We finally found it!! If you’ve read our previous posts, you know that we’ve been struggling with some engine performance problems for a few weeks now.
After what we hoped would be a simple ignition issue, it became obvious that the problem was bigger than just a misfire. We have already replaced almost our entire ignition system.
I also rebuilt our old carburator but it still felt like it was loading up at low RPMs. We upgraded the carb from the original Rochester Quadrajet to an Edelbrock 600. We changed the throttle linkage and fuel line setup and added an intake adaptor plate for the carb
That should do it, right?
I hook up the water and fire it up. It’s still running rough and no amount of adjustment to the new carb would smooth it out. Damn it!! Maybe the spark plugs are fouled out from all of the efforts to solve this problem. I pulled out all eight spark plugs. The spark plugs all look good and appear to be burning the same.
So while the plugs are out, I decided that this would be an awesome time to run a compression check on the cylinders. I pulled the ignition coil wire off of the distributor and screwed the compression gauge into the first cylinder. Cranking the motor around a few times should build a maximum compression number.
Finally an answer…
All cylinders built compression to around 120 psi. All but one! The #5 cylinder shows NO compression. Whaaat?!!! I tested it three times to be sure. Nothing. Could it be possible that our performance issues all along were because the engine is only running on seven out of eight cylinders? Of course it is.
Alright. Now we’ve got something that we can attack to finally resolve this madness. The #5 cylinder is on the port side of the engine, so I removed the port side exhaust manifold, the intake manifold, and then the port side cylinder head.
While the piston head looked to be in good shape, the exhaust valve in the #5 position was definitely bent. It was not able to close and seat properly. You can’t build any compression if the valves don’t close.
Time For A Head Job
No, not that kind. Get your minds out of the gutter!! A cylinder head job. So off to Steve’s shop with the port side head so he can have it refurbished.
Wow, two days later and the head is done. The mating surface is machined flat and super smooth. All intake and exhuast valves have been replaced. Good to go.
Steve provides everything. The refurbishing of the cylinder head as well as all of the gaskets we need to reassemble the motor. One stop. Thank you Steve.
Installation Is The Reverse Of Removal
I immediately begin putting it all back together. I had already cleaned and repainted the intake manifold and all mating surfaces have been cleaned. No more delays and the reassemble is underway.
After all of the main parts were back together, I reinstalled the spark plugs, put the carb back on, and the distributor back in.
Moment Of Truth
Okay. This is it. Jennifer hooks up the flush ears to the drive and turns on the water. We both cross our fingers and I turn the key…. Varoooom!!
It fires right up and we instantly know that our problem has been solved. The engine is cold and it’s already idling better than before with no misfires. We bring it up to temp and I make some timing adjustments, adjust the carb idle, and watch for any fluid leaks.
Almost 30 minutes of run time and all appears to be good. Jennifer and I couldn’t be happier. Time to get back to boating!!
She Says …
Lately, Jennifer has been poking fun at the raging idiot (me). I have to confess that missing my regular “aqua therapy” sessions may have contributed to my recent poor attitude.
Raging idiot? Me? Well, maybe. But the truth is that both of us are ready for a boating … anything!! Overnighter or daytrip. It doesn’t matter.
Jennifer says that it’s only half-funny when thinking of all the times I yelled “We’re trying to write a boating blog and we’re NOT boating !!”
The boat’s running great again and I’m all better now. Lol.
Hope you’ll check back for our next post where Jennifer and I hope to share another great time on the water with all of you. Please leave a comment and be sure to subscribe below. Thank you.
“See you on the water!”
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