1979 Evin. 9.9 floods lower Cyl. & won't fire

Hello to All. I'm at the end of my wits with this one. I got this motor last fall and went over it during the winter. It now floods the bottom cylinder so bad it won't fire. The plug is good, fuel new, spark fantastic, compression is 95 on the bottom and 92 on top, starts easy, will not run at idle. Runs Ok on top cylinder at start speed but as soon as I try to idle it down it wants to die and engine response is sluggish when I turn the throttle back up. I was getting water in the bottom cylinder but I changed the head gasket and re-torqued the exhaust and there is no sign of any water now. Piston tops and cylinder walls showed no scratches or scuffs. Over the winter I had it running just right. (on both cylinders) Idled nice and throttle was responsive. First trip on the boat it just never worked well at all. A list of the things I've done are
- cleaned carb. and installed a new kit.
- set linc and sinc
- set low speed idle needle
- new leg oil
- water pump
- new plugs
- cleaned ignition coil contacts
- new head gasket
- re-torqued exhaust covers
- spark is white/blue and jumps over half an inch on tester.
- taped the spark plug wires, would have replaced them but they are part of the ignition coil.
- cleaned and lubricated every thing that requires it.

Any suggestions as to what I have missed or should check next would be greatly appreciated. I'm wanting to get fishing. Thanks, Rick.

Re: 1979 Evin. 9.9 floods lower Cyl. & won't fire

well you have a single carb, so it is not the carb, it has to be spark or compression. i would say your spark is failing on the bottom cylinder. could be reed valves, but i doubt it.

Re: 1979 Evin. 9.9 floods lower Cyl. & won't fire

Thanks for that TD. Is there a way to check the strength of a spark other than a gap tester? Also, what might the symptoms be if it were the reeds? I really appreciate your help cause I'm stuck. My manual is really silent about the reeds except how to replace them. Rick.

Re: 1979 Evin. 9.9 floods lower Cyl. & won't fire

Rick,

I can't offer any help, but I'm hoping this is the longshaft you were telling me about. Good luck to you!

BOB

Re: 1979 Evin. 9.9 floods lower Cyl. & won't fire

Fuel pump pulses off of the lower cylinder. The diaphram internal to the pump had a pin-hole in it and so let's fuel go directly into the bottom cylinder. I suggest as new pump and gasket.

Re: 1979 Evin. 9.9 floods lower Cyl. & won't fire

good point ^^^^^^ rebuild or replace fuel pump.
http://www.iboats.com/Sierra_18_735...z.36857--**********.189140773--view_id.174139

Re: 1979 Evin. 9.9 floods lower Cyl. & won't fire

Thanks for that. Now I have to tell you before I did any trouble shooting I changed the fuel pump with a used one I had. It made no difference at the time but shortly after I discovered I had water leaking into the bottom cyl. and on I went from there. I honestly forgot that I had changed it by this point. If your right King P.V., I'm going to be very pleased with you and have a real good talk to myself about indiscriminate replacement of parts without proven trouble shooting first. I'll be out of town till the weekend but I will let you know if it works (or not). Thanks, Rick.

Re: 1979 Evin. 9.9 floods lower Cyl. & won't fire

Well TD wins. When I first got this motor there was half the end missing on the S.S. needle valve plastic knob. No big deal I thought because I have another. The motor was finished and tuned and ready to hit the lake in February but I had to wait til the ice was off. Took it to the lake a month ago and it ran terrible. After doing everything possible it was a last ditch effort to check the reeds before I surrendered. Well you guessed it. I found the half round end of the S.S. needle valve knob half in and half out of the lower reed. Now she is running like it did in February. I figure it must have laid somewhere and then shook into the reed on my way to the lake. Well thanks to all, but especially TD (even though he doubted it) I'm back in business. JBJ said (in good fun) I would have a better chance of winning a lottery than to have a reed valve problem so.........I'm off to get a ticket. Rick.

Re: 1979 Evin. 9.9 floods lower Cyl. & won't fire

it must have cracked off an had fallen into the carb throat. inorder to get sucked in there. reeds are very rare problems on them. do you have children Rick? sometimes they pick up something and look for a place put it. just a little help from a friend.

best buy 2 tickets.

Re: 1979 Evin. 9.9 floods lower Cyl. & won't fire

Wait a minute,
I didn't know anything about a needle knob breaking off. This is misdirection and subterfuge at its worst!
Glad you found it!
I guess when you've tried everything else and there's only one thing left.......
Later,
JBJ