TSX Carb Choke plate

[Paul Buhler]

Hi: I'm missing the spring and baffle on my TSX688 M/S choke plate. Anyone have a used one that they'd sell? Thanks, Paul

[Swawpy]

Check with Roberts Carbureter Repair- They have em. I asked about one for a carb I was rebuilding once. If a remember right they had them but said it would be just fine without it and actually can help to prevent flooding if you leave it out.

[Paul Buhler]

Thanks. At $44.00, new seems pricey. From the M/S carb manual, not having the spring and baffle means that you need to run using some choke when it's cold. The mechanical/hand sensitivity is not sufficient for as smooth and efficient running as if the engineered piece is in place.

The function of the choke valve (25) is to
restrict the amount of air that can enter the
carburetor and to increase the suction on the nozzle
(14) so that additional fuel will be drawn into
the manifold. As soon as the engine fires and
runs, the rich mixture must be rapidly reduced to
prevent stalling. This change in mixture is accomplished
by the operator positioning the choke
valve to provide the proper mixture. However,
a few degrees movement of the choke valve (25)
will make a big change in the mixture strength
and to help reduce the sensitivity of the choke
valve (25) position use is made of a spring
loaded relief valve (26) in many applications.
This valve opens automatically with engine
speed and load and eliminates a great deal of
manipulation of the choke on the part of the
operator.
When the engine has obtained normal operating
temperature the choke valve (25) must be
fully opened to assure maximum power and
economy. In addition, extended use of the choke
results in more gasoline being supplied to the
engine than can be burned. A large percentage
of the unburned gasoline is lost through the exhaust
system. The remainder of the raw gasoline
is forced between the pistons and cylinder walls,
washing away the protective oil film and increasing
engine wear, and enters the crankcase where
it dilutes the engine oil.

[Swawpy]

I think you will find that you will never know it was gone and it wont make any difference...whether installed or not. Full choke for starting...as soon as she pops shove the choke in..if it is stumbles bad maybe crack the choke a tiny bit when its cold till she cleans up, but certainly don't run or work with the choke anywhere but fully open. If necessary means something wrong and better dissasemble and clean the carb again.

[Paul Buhler]

Thanks for the thoughts. Happily it's pretty easy to remove and disassemble the carb and see if something else is causing the need for more choke. When the weather warms,my carb works as expected, but when it's below freezing, it currently needs some partial choke all the time.

Guess this falls under the heading of "tinkering". Paul

[Swawpy]

If you can't adjust it out I had extremely good luck with the small (I think #46 and 52) drill bits sold by Robert's. I had one carb in particular apart 3 times for a small miss type of stutter at idle...I just could not figure it out and was getting pissed off. I drilled the air passages they mention on thier website and it has never idled, pulled, or lugged down so well...absolutely purrrres!

[shinnery]

Motec Eng & Rest. 7342 W. State Rd. 28, Tipton IN. 45072-9001 765-983-6628 Has a bunch of carb parts also. I have never used him but I have talked to him about the carb for my basket case 440IC. I am going to send it in when I get a "round-tuit".
Bryce

[markvdh]

Missing this plate doesn't require you to run partial choke when the engine is cold, it actually makes it so that when you start it with full choke on, the engine can draw some air as it comes up to speed. That's what the quote from the carb company is saying, only in more words.

It acts like a choke pull-off does, on all the older cars and trucks with automatic choke. In other words, the choke thermostat would fully close the choke (just like you do with the cable on a manual choke), then as soon as the engine fired and built a minimal amount of manifold vacuum the pull-off would crack the choke a little bit so the running engine wouldn't flood out. That's what this spring loaded flap does; allows a little bit of air in once the engine starts running.

If it's gone, you probably won't even notice it. If you do notice anything, it won't be flooding; it'll be that when you need full choke for starting in cold weather, you can't make it happen because of the small hole that's exposed in the choke plate. If you want to avoid that problem, just cover this hole with a small permanent plate, but make sure that whatever you cover it with cannot come loose and be sucked into the engine. That will ruin your day!

With this little hole fully covered, you may notice that once you start a cold engine you have to push the choke cable in just a bit so it doesn't flood, but that's nothing new. We've all had to do that for years with most of our tractors, grain trucks. chain saws, anything with a manual choke without this little spring loaded door.

Hope this helps in understanding it's function.

Mark V

[CELSESSER]

I think a lot of those pieces that are missing went right through the engine.

[Paul Buhler]

Thanks for the info and help.
I'm hoping that the missing baffle and spring are due to someones fat fingers losing them, but if they were sucked through, it happened before my watch.
Since the dozer starts easily and runs clean and strong, I'm not too concerned, I just like to do little (sometimes big) upgrades as time, focus and monies allow.

It is really nice this winter to have a machine that I can fire up on demand without fanfare and push back the snow banks, pull in some wood, set out sap buckets, or now regrade the rutted drive. That reliability has real value to me - I've dealt with the "first I gotta fix... then I can use it" type machines. I really prefer my wifes teasing me about my running toy rather than about some piece of junk that's in the "fix to use" category.

Now if the pin and bushing project would just gel at a good price I'd be a happy camper. Paul