Author Topic: TM32 advice for a dyno run?  (Read 19526 times)

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Dave1

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Reply #30 on: October 25, 2015, 03:16:10 pm
It has not been tested since it has come back from the Dyno shop. I know how to test the carb mount for leaks with silicon spray, if it revs up then it is not fine.

When you say intake and exhaust, are you referring to the valves? Or the carb mount and where the down pipe exits from the head?

I have just got back from a test ride with the 45 fitted. Same story. Idles ok ( not good and not great, certainly no better than the Amal Monobloc I had fitted to my old RE), pops and misfires on deceleration,with throttle fully closed..Quite regularly. Soon as you accelerate, the bike runs really strong.

I am determined to get this carb to work, as I can see real potential with it, but if it doesn't start behaving at idle and on decelaration then...
« Last Edit: October 25, 2015, 05:28:24 pm by Dave1 »


ace.cafe

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Reply #31 on: October 25, 2015, 06:20:18 pm
Well, we can get a directional understanding of the issue because your carb is the only one that is exhibiting this behavior. I have never seen any other TM32 on any Bullet that needed any other pilot jet than 30 at sea level.
Try cleaning out the idle circuit passages.
Make sure that the fuel in the tank and fuel bowl has no water in it.
The air bleed screw should start out at about 1.5 turns out.
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Dave1

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Reply #32 on: October 25, 2015, 08:10:56 pm
Before I take it apart again to clean it, I am going to do an air leak test. I put fresh fuel in the tank yesterday, so no water in fuel or fuel bowl.

I have been starting with the air bleed screw 1.5 turns out. With all pilot jets.

I have put a photo for you all to look at. In case you spot something ( long shot I know ).

I was thinking to take the pilot jet out, and blow through the pilot circuit with compressed air. If anyone sees an problem with that let me know.
« Last Edit: October 25, 2015, 08:16:35 pm by Dave1 »


Adrian II

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Reply #33 on: October 25, 2015, 09:02:31 pm
Quote
I have just got back from a test ride with the 45 fitted. Same story. Idles ok ( not good and not great, certainly no better than the Amal Monobloc I had fitted to my old RE), pops and misfires on deceleration,with throttle fully closed..Quite regularly. Soon as you accelerate, the bike runs really strong.

Could be an air leak in the exhaust?

A.
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DanB

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Reply #34 on: October 25, 2015, 10:33:20 pm
Quote
When you say intake and exhaust, are you referring to the valves? Or the carb mount and where the down pipe exits from the head?

The carb mount and the pipe on the head. Your spot on with the spray (I've never used silicon; wd40). I've got the same carb and I use a 27.5 and 30 depending on the temperature. I've got an AVL but as ace has said, 45 is really out there for an IB or AVL. What type of mount do you use?  Could the rubber be cracked finely?  Does it have that extra air line on the top of the carb mount for a PAV? 

Good luck an us know what u find with the leak check
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Arizoni

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Reply #35 on: October 25, 2015, 10:52:29 pm
I always thought backfiring on decell was due to the air/fuel ratio being too lean.

Air leaks into the area of the inlet valve will make the air/fuel ratio too lean and is one possibility if backfiring is happening.

Too lean of a mixture due to incorrect jet sizes (too small on fuel control jet or too large on a air control jet) is another possibility.

Also, if the fuel in the float chamber is too low an overly lean air/fuel ratio can happen.
Jim
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Dave1

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Reply #36 on: October 25, 2015, 11:40:29 pm
The carb mount and the pipe on the head. Your spot on with the spray (I've never used silicon; wd40). I've got the same carb and I use a 27.5 and 30 depending on the temperature. I've got an AVL but as ace has said, 45 is really out there for an IB or AVL. What type of mount do you use?  Could the rubber be cracked finely?  Does it have that extra air line on the top of the carb mount for a PAV? 

Good luck an us know what u find with the leak check

I use the rubber mount with metal spacer, which is a Mikuni product. See the photo above DanB. The rubber does have very fine cracks. There is nothing for a PAV. I'm just going to do an air leak test and see what happens. And clean the pilot circuit. If that doesnt work then I will make a video, and post it here for every one to see.


DanB

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Reply #37 on: October 26, 2015, 03:25:29 am
Ah, I missed the photo. Thanks. Is that carb supported with the pod filter?  If not, I'm nearly certain it's an air leak. The extra weight plus vibrations of the fuel system hanging off the rubber has been a source of trouble for a number of folks.

A video would be helpful if this doesn't help.
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Dave1

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Reply #38 on: October 26, 2015, 07:00:03 am
DanB, the air filter is in the photo, it is the K&N pan/pod filter you can see.

If I get time after work, I will do the leak test tonight. What way do you do the leak test, if you don't use silicon spray?


ace.cafe

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Reply #39 on: October 26, 2015, 12:19:04 pm
I can see a crack in the rubber in that photo.
Never run an unsupported carb on a rubber manifold.
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Ice

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Reply #40 on: October 26, 2015, 01:29:06 pm
Dave, give WD-40 a try. 
 BTW rubber parts are perishable wear items.  They age harden even when just setting on the shelf.
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DanB

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Reply #41 on: October 26, 2015, 01:34:49 pm
DanB, the air filter is in the photo, it is the K&N pan/pod filter you can see.

If I get time after work, I will do the leak test tonight. What way do you do the leak test, if you don't use silicon spray?

I use wd40 or a carb cleaner. Whatever comes to hand first really. As Ace says, you need to make a support or hanger for that filter/carb combo when you replace the manifold. The filter itself is irrelevant. It's the fact it's just hanging on the carb without support that's creating the problem together with the failing, cracked rubber.

I also seem to recall another poster on the forum that had problems with using a pod filter as it covered or inhibited the carb intake mouth by blocking the air jet openings....  Think it was bedlam...
Suppose I were an idiot, and suppose I were a member of Congress; but I repeat myself. ... Mark Twain
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Ice

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Reply #42 on: October 26, 2015, 02:31:51 pm
 and those tiny little inlets are absolutely crucial to the metering & mixing and whatnot that goes on inside the carb. 
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tooseevee

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Reply #43 on: October 26, 2015, 02:49:02 pm

...... So I started to turn the throttle stop screw in, I got it to idle for a very short amount of time before cutting out. So I kept adjusting the throttle stop screw in, it did slightly improve, then I ran out of adjustment. Adjusting the throttle stop screw in, is of course leaning the mixture out, by letting in more air. So I am going to fit the 30 pilot, and try again, when the engine has cooled.

            Ya know, you've got to start keeping your terms straight. It can be very confusing at times to know what you're doing.

              The Throttle Stop Screw doesn't lean out or rich up anything. The throttle stop screw only adjusts idle Speed up or down. It doesn't change mixture.

              The mixture screw (or air bleed screw if you want to call it that) is what changes the air/fuel mixture.

               And you say above "adjusting the throttle stop screw in is, of course, leaning the mixture out, by letting in more air".

                Now if by throttle stop screw above you mean mixture screw, that's wrong. Screwing the mixture screw in reduces the amount of air thereby richening the mixture. 

              You're getting backfiring on deceleration and other indicators of lean and others have suggested an air leak at the manifold (and I think your shop suggested an air leak) and yet you seem reluctant to chase that. Put a new manifold on the damn thing and seal it. And nobody in the world runs a TM 32 with a 45 pilot in an Enfield.

            And you can't run an unsupported carb. That alone may contribute to a manifold crack. You've got to start back at square one, I think, and do it all step by horrendous step. It took me practically a whole riding season to first learn and then dial in my TM 32 (and other associated glitches) step by tedious step, when I first put it on. It's a bitch, but that's whatcha gotta do.
     
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ace.cafe

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Reply #44 on: October 26, 2015, 03:27:46 pm
I just can't help mentioning that all of the potential issues on Bullet inlet tracts have been solved by us long ago. The manifolds, rubber hose issues, carb type, jetting, unsupported carb matter, and airbox/filter are all solved and clearly proven over and over. Yet, some still persist with the pod filters and other inlet modifications which invariably result in problems. Why not just do it right to begin with? We didn't develop all this stuff for no good reason. Part of the reason why all the Fireballs work so well is because they are built according to my instructions, using our proven designs. Things don't need to be nearly this difficult.
Friendly rant over.
 ;D
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