1972 Mate 2 Carb low speed needle valve tip broke off in seat

[lindy46]

I spray fogging oil in my empty tanks when I store them.

 

[jpian0923]

Still running rough, miss firing. Here is a youtube video of what it looks like. What next? Compression test? New fuel mixture? Bent shaft?
https://www.youtube.com/watch?v=5jM7j4YXu6k

 

[hardwater fisherman]

No Title

I have never owned any motors with on board fuel tanks but I have heard others say that there is a filter in the shut off valve. Maybe it is blocked?

 

[lindy46]

Still running rough, miss firing. Here is a youtube video of what it looks like. What next? Compression test? New fuel mixture? Bent shaft?
https://www.youtube.com/watch?v=5jM7j4YXu6k

Yes, check compression, but also check spark. Sounds like one cylinder is cutting out.

 

[oldboat1]

think you might be missing a point -- expansion plug is a routine replacement part that is part of cleaning and rebuilding. The plugs are included in rebuild kits. You remove it to clean out the idle system. There is no law that says you have to do it, but you risk poor idling if you don't open it up and clean it.

With that other carb**, you should expect to clean it and put in a rebuild kit, replacing its expansion plug after cleaning under there. (As you intend, push that broken tip out from the inside of the current carb, after taking off the plug. But don't drill it out.)

**(edit.) that is, if you pick up a replacement carb....

Get a kit, clean and rebuild the carb. While you could have an ignition issue, that rolling gait sounds like a carb issue -- running too rich -- would set h.s. needle at 3/4 open to start, l.s. at maybe 1 1/2. In current condition, just try leaning both needles (clockwise) in 1/8 turn increments, starting with the l.s. needle -- your air/fuel mix. When complete, the h.s. needle should be just rich enough to allow you to bump up the throttle without engine hesitation, but no stumbling from rich running. The l.s. needle setting should allow you to idle down to the point at which you can virtually count the revolutions. You are after the leanest setting at which the motor runs smoothly -- likely to even out and increase rpms as you adjust, and you would set throttle to slower idle accordingly. 50:1 is the gas/oil ratio.

 

[jpian0923]

I did a carb kit. Now I'm noticing, on the second carb, the high speed needle is bent and is leaking fuel a bit. I'm swapping the bottoms of both carbs. Also, the two jets right above the carb mounting holes, are not able to breathe because they are pressed up against the bracket. Is that normal?
I checked compression and am getting 100 psi.

I miss spoke about the "jets"on the carb, they are "ports".
I had previously cleaned out the fuel screen. I had previously checked the ignition system, everything checks out ok.
I followed this troubleshooting page for the ignition system and everything checked out ok: http://assets.fluke.com/appnotes/ele...r/B0271b_u.pdf

 

[oldboat1]

need a couple of packing washers and a gland nut on the h.s. needle.

 

[jpian0923]

Is there an equivalent "old car" set of points and condenser I can use from Autozone or O'Reilly's?

 

[lindy46]

NAPA should be able to order Sierra tune-up kit - 18-5011
Or get it right here at iBoats http://www.iboats.com/Johnson-Tune-U...view_id.271401

You may also need new coils, and it's easy to change them once you have the flywheel pulled to do the points and condensers.

 

[jpian0923]

Thanks for all the help gentlemen! The conclusion video can be seen here: https://www.youtube.com/watch?v=JCKcJFmWWAQ
Turns out it wasn't the carb, it was the points gap. A couple of weeks of chasing the fuel gremlin and it came down to a cheap feeler gauge.

 

[lindy46]

That sounds much better! Glad you found the problem.