General Category => Engine & Transmission => Topic started by: Mike Sal on February 06, 2012, 05:21:51 PM
-
Pulled the sediment bowl & tank off this evening. Both with lots of mud which used to be gasolene. The quart of dark stuff that came out of the tank was doing it's best to convert to varnish. I'll take the tank to a local shop tomorrow to get it boiled out.
You guys didn't tell me it's a real pain in the butt to pull the carburator off. I ran out of time before getting if off tonight. I'll have to dig out my odd bent wrenches to get that back side nut off. I did notice that the front side nut wasn't snugged up to the carb flange & I could wobble the carb a little. Not sure if this means the flange is warped or if the guy just didn't get it snugged down.
Mike Sal
-
I'm curious if yours has those unique locking nuts on your carb like mine did. Mine had a tiny little wire coming out of the side that would poke into the threads of the stud tokeep it from vibrating off.
-
Do you mean your carb studs are drilled for cotter keys (or safety wire)? The nut on the left side didn't seem to have anything special going on about it (it won't come all the way off without the passenger side nut being loosened also, as there's not enough clearance between the nut and the rest of the carb body.
I'm just coming off a bout of stomach flu, so didn't work on the bike at all since yesterday. Maybe tomorrow evening I'll feel good enough to get in there to pull the carb all the way off. That passenger side nut is going to be a bugger. Since I'll have to pull the engine mounting bolts anyway to get to the kick starter shaft nut, maybe I'll just go ahead & pull it out on the bench to work it over. I really wasn't wanting to do a complete tear down yet, but ya know how that works.....
Mike Sal
-
The tiny wire came out of the side of he nuts and pointed into the threads of the stud so that if it tried to vibrate off the wire would jab itself into the threads and prevent the nut from coming off. Those carb nuts are in a close area. i think if you back them off a little at a time alternating from one to the other it won't be a problem. Mine had a belt guard that went under one of the nuts that i had to contend with. I'm in to being all original and re-used all my hardware. I had all mine re-plated and used them again to preserve originality.
-
Pulled the carb off yesterday. disassembled & soaked it in fresh gas, then cleaned the parts tonight. I felt good that the carb had a bunch of black crud, but no white corrosion. The black crud dissolved really well & it all cleaned up like new. Anyone else pay attention to the numbers cast into the bottom of the bowl? Not sure if they're part numbers or date code numbers.
One thing I've got to source is the "packing" used on both ends of the gas line and used on the needle valve (under the nut that seals & holds it from turning). All three of mine disintigrated during the cleaning process. Not sure if they were leather or rubber.
Oh, and the nuts holding the carb did not have the special locking feature kartjockey spoke of. They had internal tooth lock washers.
Mike Sal
-
Pulled the carb off yesterday. disassembled & soaked it in fresh gas, then cleaned the parts tonight. I felt good that the carb had a bunch of black crud, but no white corrosion. The black crud dissolved really well & it all cleaned up like new. Anyone else pay attention to the numbers cast into the bottom of the bowl? Not sure if they're part numbers or date code numbers.
What are the numbers? I have heard that Tillotson stamped the venturi size in there? As in xx/32"?
-
The numbers stamped in the body (on outside of the bowl) is MT57A. The numbers cast into the bottom of the bowl are in a circle & are "209076" with "518" in virticle orientation the middle (the 1 is sideways).
Mike Sal
-
Do you think that could be 5/8? MT 57A was the last carb used by simplex.
-
It's possible it's 5/8. It looks like about that size when I look down the throat. Not sure if the picture will turn out or not. Hmmm, I wonder when they started using the 57A carb.
Mike Sal
-
Oops forgot the picture
-
What did Simplex use for a throttle return spring? I see an extra hole on the linkage, but I didn't see an obvious place for the other end of a spring to attach.
Mike Sal
-
They didn't!
-
Hmmm....kinda like built in cruise control huh....
I wonder if a guy could stick a coil compression spring on the cable inside the twist grip assembly?
Mike Sal
-
Makes it easy to ride with no hands!
-
I've not tried to take the throttle grip apart yet....any tricks or tips? Dont' want to goof up the cable I can avoid it, as this one is in pretty good shape (I wonder if maybe it's been replaced somewhere along the line).
My handle bars are a little rusty (not too bad, but bad enough they'll have to have some attention.....I'm thinking of painting them black), so I'll have to take it apart sometime.
Mike Sal
-
There is a spot in the throttle that has sort of a detent to be like cruise control. My MS style tillotson has a spring that goes aqround the throttle shaft kind of like a torsion spring. I added a small spring at the carb to have good throttle return.
-
Tom, does your bike use the pin type system? On the later ones they use a slide style.
Rick
-
It has a pin that fits in a track and to throttle up you actually twist reverse of modern day motorcycles.
-
It has a pin that fits in a track and to throttle up you actually twist reverse of modern day motorcycles.
The later style twists in the same direction as a modern motorcycle. I find it ironic that custom bike builders of today brag about hidden throttle linkage and simplex had it in the thirties.
-
Since I've not been able to get in touch with Wayne, I thought I'd check to see if the local parts store could get the gasket kit for my carburator. The NAPA store catalogs don't even list any MT series Tilloston carb. I wound up making my own (I really needed the packing gland for the needle valve....made one from some leather I had laying around).
Mike sal
-
Cushman used tillotson mt carbs. Dennis Carpenter Cushman has the rebuild and gasket sets.
http://www.parts123.com/parts123/yb.dll?parta~dyndetail~Z5Z5Z50000024u~Z5Z5Z5ABESB~P5.25~~~~S3FN0RJ60Y69123917924c~Z5Z5Z5~Z5Z5Z50000024U
-
I couldn't get the shopping cart to work on the website, so had to call the 800 number....they told me minimum shipping charge is 10 dollars.....for a 5 dollar gasket set......Hmmm. Guess I stick with the homemade gaskets.
Mike Sal
-
Typical mail order! You would think they would throw that in the mail for $1.
-
Mike
I just used the Dennis Carpenter Web site to order a gasket and screen for my Tilson Gas Filter. The web site worked fine for me and got my parts already. The shipping is a killer $9.99 for $4.00 of parts. I will still use them , but get a list of parts first to save on the times I use them. It is nice to know that we still can get a few parts still. Bill
-
I was able to re-use the parts in my sediment bowl. The screen was pretty clogged, but after soaking & working it over with a fine brass wire brush, it's good as new. The gasket was still pliable too. The only part that was saved was the rubber packing gland for the fuel line. It disintegrated. I'm thinking about replacing that aluminum fuel line with a piece of brake line & using flared fittings.
Mike Sal
-
I used copper lines and compression fittings.
-
Copper lines & gasoline are not a good thing. It's not a matter of if, but when, it will work harden & crack. I've been forging copper quite a while (one of my other hobbies is blacksmithing) & can tell you copper doesn't stay soft. I know people have used copper lines over the years, but I don't think it's worth the potential risk.
Mike Sal
-
I figured with a limited use bike I would be fine, but in light of what you said, I think I will change to aluminum.
Rick
-
What oil ratio are you guys running in your engines? Back in the old days when I lived on a lake & did a lot of dirt bike riding, I used 40:1 in every 2 stroke engine I had (140hp Mercury outboard & various motorcycles that were old enough not to have oil pumps) & never had any issues of any kind. Just curious how these little long stroke motors get along.
Mike Sal