Bad reed valve?

[42 Clyde]

What symptoms could i expect if i have a bad reed valve? I have a 1959 Sea King 35 hp. The reed valves are one of the fue things i did not replace during its over haul. Is it also possible for it to work sometimes and not work other times?

 

[racerone]

simple answer ---NO-----Reed valves are very reliable.------But the screw could be loose and they are not sealing.----What does your motor do / not do ?

 

[42 Clyde]

It will vibrate and jerk around at idle. I have seen lots of videos of these motors and that doesent seem to be out of the norm. But it continues all the way thrue wide open throttle and vibrate the whole boat. It will also fail to get up to full rpm. The only equivelent i could describe is a car engin with a dead cylinder or two. However it did smooth out and i got a boost in power and rpm for a couple seconds but had to let off the throttle due to kayaker. I could not recreate it again.

 

[F_R]

Don't know what's wrong with your motor, but you are barking up the wrong tree if you think it is reed valves. How about water getting into a cylinder? Surely you must have checked the ignition, right?

 

[racerone]

Run with a timing light hooked up and see how spark behaves as you speed up.-----Test run on both leads one at a time.

 

[42 Clyde]

The ignition is 100% new parts. But with that being said, new parts are not a guarentee. what would i be looking for with the timing light? I can jump into that tomorrow.
No water in the cylinders and it has a new head gasket from when i did the rings.

 

[Triumph55]

New plug wires? Fully seated in coils? Any condenser or coil wires rubbing on flywheel?

 

[racerone]

Good luck with it !!

 

[42 Clyde]

It does have the old plug wires. I cut a half inch of the end of each one to disect it. No green cancer and zero ohm resistance.
funny you mention the wires rubbing on the fly wheel. I did descover some of the wire casing missing from the ground wire for one of the coils. I figured it had to be rubbing. I fixed that but nothing changed.

 

[42 Clyde]

I just checked the spark with a timing lite. The spark is very stable and consistant and follows the ignition asembly as i advance and retard the timing.

What would be considered bad compression for this motor? Right now i have 90 psi in both top and bottom. I just did a full overhaul on it and 90 just seems low to me. If it is to low could that be a contributing factor? Will it affect the motors ability to idle?

 

[42 Clyde]

I think i have the problem isolated to the bottom cylinder. The motor can run on the top cylinder alone at high idle but not run at all on the bottom cylinder alone. The rpm will lower and evin out when i pull the bottom plug wire. I tried swaping spark plugs to iliminate that as the culprit. No change. I tested the spark with an open air gap tester. I did find that the bottom cylinder has a much stronger spark than the top so i dont think that is a factor. I guess im running out of things to test. If anyone has a direction to go in i will try it.

 

[racerone]

Check the fuel pump.----Check the reed valves.

 

[42 Clyde]

What am i looking for in the reed valves? How do i test them?

I have tested the fuel pump by squezing the primer bulb. The Fuel pump is working.

 

[42 Clyde]

Does any one know what the compression is supposed to be on a late 50s to early 60s omc 35 hp motor?