Leaf plate

[hgxsilver]

Ive only done a compression test not leak down. Both are sitting around 110-115

 

[hgxsilver]

Fired it up again this weekend. Similar run sneezing and heating up. Ran it at home later in a bucket for 30 min or so. Enriched the idle no sneezing no over heating.

 

[hgxsilver]

This is where I am now. Took it for a ride today with a new condenser for the top cylinder (which had been covering the plug with carbon). Ran well until warmed up, started sneezing a few times. It was clearly becoming a little overheated until it didn't run well. Cooled it down for a couple minutes and it started up and ran great before loading it onto the trailer. I still have not been able to actually tune the carbs high speed to 4500 rpms. I noticed at higher throttle it was nearing 3700 but due to the sea state I was unable to continue with that today. During the higher speed, the engine did have bursts of high revs almost startling me, maybe slipped out of gear, but again might have been due to the waves. I have not yet checked the head gasket, there is salt crystallization around the cylinder head, and the exhaust port cover gasket. Hopefully not too vague of an explanation.

 

[F_R]

Champion plug charts will tell you to use anything that will fit the hole. NOT to be trusted. Going just by memory, I believe the correct plug was J4J. Probably have to settle for J6C now. Nothing hotter. And not the "U" series.

 

[oldboat1]

Think the early '60s motors used the J4Js, but the '57/58 35s used the J6. The RDS-20 did have a t.stat, though, like the '60s 40s, so that might be a rationale for the J4. (pretty sure either would be fine -- wouldn't hurt to experiment with both, and see what works best.)

 

[hgxsilver]

I think my final problem is fuel delivery. Only sneezed when throttle is above idle range. Like mentioned before the diaphragm is quite stretched, got one on order. Otherwise trolling around all day was great. No overheating.

 

[racerone]

Maybe throttle plate is opening too early.

 

[hgxsilver]

I’ll check the link n sync out again

 

[hgxsilver]

I have been searching the web for ideas for possible problems like mine. Having a hard thump or shudder at high speed got me thinking it was slipping out of gear. Maybe the clutch dog was worn or the inside of the gears. I would assume that the original fitting of those gears and the dog are slightly rounded anyway, so I ruled out that. I disconnected the shift cable to allow full movement of the shift lever and that didn't fix it either. Installed my new fuel pump diaphragm and readjusted the link n sync. Any other ideas

 

[racerone]

Time to inspect lower unit.-----There should be no rounding of gear / clutch dog on this motor.

 

[hgxsilver]

The conclusion,

Clutch dog was worn so I swapped that with another fixed that problem, head gasket ended up blowing a hole so new head gasket. New crank shaft seal led to better idling. Prior to installing new plugs, the threads let go of top cylinder so had to swap the head from 64 big twin. All is well. Thanks