More help please

[Dave_Knowles]

I have been trying to sort out the starting problem with my boat today. I put new plug leads, coil, points and distributor cap on and it started but as soon as I tried to get it to idle (once warm) it stopped. As it would not start again I checked the points and they were ok and at the same time checked the spark which was good and healthy. On putting it back together and trying to start it one of the Solex carbs was coughing a lot. The back one seemed fine. The engine did eventually start but was very unhappy. As soon as I opened it up the front carb once again started cioughing. Now carbs are not my favorite thing to work on so I wandered if someone could give me an indication as to where to look first for a possible solution.

<hr width=100% size=1>Take care.

Dave

Dave Knowles
Southampton - UK

http://www.MyCleopatra.co.uk

 

[Col]

Stuck inlet valve??

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[Dave_Knowles]

You think that in preference to a blocked jet. Presumably I could do a compression test to see if a valve is the problem. One thing with my engine it has always tended to cough a lot on start up but once warm runs smoothly.

<hr width=100% size=1>Take care.

Dave

Dave Knowles
Southampton - UK

http://www.MyCleopatra.co.uk

 

[BarryH]

Nah sounds like the solex buckets are pulling unevenly, just for starters.
Right idiots guide to balancing the buckets. First if disconnect the throttle cable. Then back off both throttle stop screws. Then loosen the spindle clamps. Adust these until the tabs on the end of the spindles are sitting in the middle of the forks on the clamps.
Tighten clamps and make sure nothings moved. Turn both throttle stops in until they only just touch the carb bodies.
Now theres an air volume screw on the back of the carb, the bit the oposite side to the engine. Turn these in until they only just seat. The tip of the screw is a cone, so don't over do it or you'll bugger them. Now back of the screw 1.5 turns.

That as they say is it.Thats put the buckets back to basic initail settings. Try it again. While your at it make sure both accelerator pumps are pumping. Just operate the throttles a couple of times to se if the pump jets squirt. Tjhey should both spirt more or less at the same time. BUT to get them running in proper balance and tune you'll need a carb balancer. OK go get that cheapo Gunson on and a catering size of baked beans. I let you in on that little secret later. Your lump should now splut splut bang roar into life.

Also. I know that you've put new ignition gubbin's in. What have you set the spark spark bang timing at. Initial on your lump is about 6 degrees. Which is fine till you try to brm brm rev it. The timing needs to be set at full advance 34 degrees btc at lots of roar roar revs, 4000 I think.

What else, air leaks, valve gear sticking as col said but I doubt it on that lump. Cam timing. If the knobbly stick isn't playing the same tune that'll give the same symptoms
Dunno what else really without have a dig and poke. That'll little lot will keep you occupied this afternoon anyway.

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[Dave_Snelson]

Barry's advice is good and you can perhaps check things in an easy way before embarking on stripping stuff down by doing two things first. 1) Compression check, as per your own suggestion and 2) Take a piece of plastic tube 1/4 or 1/2" diameter, long enough to stick one end in the venturi and the other in your ear. Nope, I'm not kidding. At idle, listen to both venturis. They should both sound the same in terms of sucking noise. I can't mimmick this for you here, but if one sounds shhoooosh and the other sounds sheeesh. then the sheeesh one one is more closed than the other. Trust me, honest! I used to balance a 4-cylinder racing Honda motorbike engine with a carb per cylinder this way and it ran great. As you have points, the other excellent tool to use is a dwell meter. This is without doubt the best way to set points in the world, all you need is the spec. I used to set mine while the motor was running at idle. Dwell takes into account any irregularities in breakers.

Anyway, I'm rabbitting 'cos I've been down the pub and I'm now enjoying a glass of wine - cheers.

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