14 HP McCulloch Question

[flyingscott]

Well now the dang thing won't start at all. All I did was fiddle with the adjusting screws. Thought I had a Carter carb, but turns out it's a Tillotson. Never even heard of these and can't find this exact carb online. The m/n is: MD 1388. I was told to set the idle and high speed screws at 3/4 from seated and also 1 1/2 turns out. I tried both and she won't even pop. Also does this carb lack a low speed adj screw? I sure don't see one. The only thing that looks like it could be it is near the bottom of the bowl and it seems like it's too tight to be an adjuster. Thanks again for all the help, but looks like I'm going to need some more help to get this gem going.

The top screw is the low speed screw. Where are you located? Maybe time to join the AOMCI. The top screw should be set at either 3/4 or 1.5 turns out. Are you using the throttle ? The choke? To start it. The bottom screw is the high speed screw and is held in with a packing nut to prevent it from vibrating loose. Both adjuster should be snug to prevent vibrating loose. When you tighten them only slightly snug to tight and you will ruin the needle tips.

 

[LaqueRatt]

The top screw says idle, which I find kind of confusing. Most carbs I've messed with you adj the idle with a set screw that rests against the linkage. This one I guess is for adjusting mixture? At idle? So it's actually the low speed adjustment? I know better than use a lot of pressure to seat them. If I damaged them they must be pretty delicate. I'm not sure if I'd say either screw is snug. Should I try to tighten the packing nuts?

This is how I just tried to start it:

Set both screws to 3/4 out. Squeezed bulb until firm. Full choke. 3 pulls, no start. Choke off, 4 pulls, no start. Choke back on, 3 pulls, no start. At least I was able to verify it is getting spark. After the 2nd attempt to get her going I pulled the plugs and they seemed almost dry, not fouled. Gave the bulb another squeeze, one last try. Nothing. Pulled plugs again and definitely a little wet. I've now got both plugs out to make sure any excess gas evaps out.

I live in a little resort town in Indiana. All I want to do is go fishing. This is why I gave up snowmobiles. I was wrenching more than riding.

Thanks for the link to the carb kit. Good to know you can still get them. Watched a vid on it though, not my exact carb, different MD carb and boy it sure didn't look easy. Are there plugs that need to delicately be removed to clean these things? Guess I'm up for that, but with the kinda luck been having lately I just might booger it up.

 

[racerone]

Does spark jump a gap of at least a 1/4" ( 6 mm ) or more on a test device ?-----Spark plugs are not a good way to test for good / strong spark

 

[LaqueRatt]

I'm not sure. Used a spark tester that I bought for lawnmowers. It's a plastic chamber with leads that connects between the plug and the cap. Hard to ground a plug with one hand while pull starting with the other. I like to stick a screwdriver into the boot and ground it or sometimes put spare plug into the boot and ground the plug. Is there an easier way?

You have a point though the spark could be weak, but wouldn't it try to start or at least kick a bit?

 

[LaqueRatt]

OK, I figured out what you guys mean about measuring the spark gap and ordered the tool.

My current thoughts are to clean out the carb and pull the flywheel to inspect the points. I'll wait on the points though until the tool comes tomorrow, but suppose I need to get in there for a looksie anyway, right?

Also I measured the compression and have about 80 top, 90 on the bottom, hard to be sure because it goes back down to 0 within a minute or so. It could be my old vac gauge is faulty, but it seems to be in good shape. Put a little grease on the O ring where it meets the head, but that didn't help. I was going to squirt a little 30W into the plug holes, thinking the cylinders could be washed dry but it started raining and I had to quit.

Any thoughts? Am I thinking right here? Shouldn't she hold compression for at least a little while?

 

[flyingscott]

No they do not hold compression.

 

[LaqueRatt]

OK thanks a lot! I was a little worried actually. Guess it's time to roll my sleeves up. As soon as I get a stand built going to have a look at the points. Might squirt a little fuel into the cylinders first though just for the heck of it to see if she kicks.

 

[LaqueRatt]

Well I got the spark tester and as far as I can tell she's not making a spark. I'm never confident though when I can't find a spark that maybe my ground is no good. There is no bare metal anywhere, it's all painted. I squirted some gas/oil mix into the plug holes and pulled it a bit, no start. Think it's save to assume I got issues with the points and condensers. I'll try to clean and regap them, but think it might be a good idea to replace them. I can't find any though. Can somebody point me in the right direction? Ebay has some, but they seem brand specific and of course nothing for a McCulloch. Has anyone had any luck adapting car parts?

 

[LaqueRatt]

OK the points look fine. Sanded lightly with 320G and re-gapped. Business card dragged through had a slight stain and it looks a little wet under where the points mount. Is this a problem? Also should that little fuzzy piece get a drop of oil or maybe white grease?

 

[LaqueRatt]

Woohoo! Finally got her running and wow what a nice little motor. Smooth from idle to WOT. Pushing lots of water out of both holes. I didn't kill it after all!
Now I can't wait to get it out onto the lake. Something odd about this motor is that it won't do squat unless the throttle is mostly open. Now that I know that she starts on the first pull. Thanks for everyone who helped me along. I couldn't have done it without the help from the members on this site.

You're not done with me yet though. Now I got an Evinrude Fastwin 18 on the stand. Hoping to get away with just cleaning the carb.