New Idiot on the Block

FreeRadical said:

Thanks, Mark. Knew I could count on you. What's you take on the oil additives? Zddp vs. Marvel Mystery Oil?

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Kevin, I've never heard of running Marvel oil to offset the missing ZZDP in modern oils. Maybe I've missed this thread. If you're concerned about your tappets you can buy a little bottle of ZZDP and add it to your oil. I've got a little bottle of the stuff I got from a friend who runs an oil company that blends oils for industrial purposes. I must admit I usually just run Valvoline bike oil and get on with my life. I'm sure the other guys here can give you more scientific advice.

It does not matter much what lube is put in the primary or the gearbox so engine oil it fine but I like ATF in mine affer very seasoned UK owners recommended it.

hobot said:

It does not matter much what lube is put in the primary or the gearbox so engine oil it fine but I like ATF in mine affer very seasoned UK owners recommended it.

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Plus, when you run red ATF in the primary, it's easier to tell where the inevitable oil leak is coming from.

Any good motorcycle specific oil should be fine without additional ZDDP.

I personally use the Quicksilver Full Synthetic 20w50 oil from Wally World in all my bikes. I had used the Shell Rotella 5w40 syn diesel oil but I could tell it was a little thinnner from some additional engine noises so went back to the 20w50. Have had no problems since. The ZDDP ratings on the Quicksilver were perfectly adequate.

Ditto the ATF in the primary

I believe you need HPGL4 gear oil for the trans. That is supposed to be yellow metal safe I think was the concern. If I recall, 75w90 was the std weight.

What you might have a hard time finding is the 140wt for the swingarm pivots. I can say that when you get the proper thick oil for the swingarm, it doesn't leak. I tried the multiweight 80w140 or whatever and it would leak out. But the straight 140wt does not. A tractor supply store or some such farm store will have it. I've not seen anywhere else that does.

For the newbies, only time ZDDP maters is on start up and operation below 2000ish rpm cam oil wedge surfing so if reving right up on start ups and not spending much pleasant slow idle time even water would work well but for boiling off and rust. If ya let idle much before shut down you have rubbed off most the protective nano layer we are all so concerned with that only gets desposited on over boil temp surfaces. Last couple years I went against the grain on wet sump starts going to 2000ish right away using 15/40 Rotella diesel and pleased on each sump mag check not to see anything worth wiping off instead of pile of shavings I saw on both my Combas prior years treating them like tender babies needing a pat and a burp after a meal.

Hello all,

It's time to put together the carbs today. As usual, I have more questions. I have included some pictures to help explain...

I received my carb refresh parts today including the manifold seal. The previous insulators are made of some kind of perforated metal; however, the new ones look to be made of a completely different material. The Andover parts fiche has two part numbers (067842 and 063458). I'm not sure which one I have, but I assume I just razor-blade the old ones and use the replacements.



My other concern is regarding differences in the LH and RH carb. The LH carb seems to have MUCH better air flow from the two tiny holes in the carb body (pilot mixing chamber?) than the RH when I shoot my compressed air into the gas intake hole (see pic). I have cleaned and prodded the living daylights out of all orifices. I even bought the tiny .016" drill bit to clean out the fixed pilot jet. I've even shot carb cleaner directly into the gas intake hole. I've spent HOURS cleaning this thing. Should I be worried that the two don't act identical?

Again - thanks for all the advice!

it would be a good idea to insure that the flanges are flat, use a plate glass and grinding compound to fresh the mounting surface.

think most are using an O ring for the carb to manifold gasket. sure others will chime in

Dennis

FreeRadical said:

Hello all,

It's time to put together the carbs today. As usual, I have more questions. I have included some pictures to help explain...

I received my carb refresh parts today including the manifold seal. The previous insulators are made of some kind of perforated metal; however, the new ones look to be made of a completely different material. The Andover parts fiche has two part numbers (067842 and 063458). I'm not sure which one I have, but I assume I just razor-blade the old ones and use the replacements.

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The thin perforated graphite gasket is not the correct part. Looks like an exhaust gasket. The P.O. probably bought it from a lawn mower repair shop.
The thick Andover heat insulator gasket you purchased is the correct part.

Not sure what to tell you about the carb pilot circuit. It sounds like there's still a blockage. Do you have access to an ultrasonic cleaner?
Or maybe inject some acetone or something stronger and let it soak. Modern carb cleaner is notoriously useless in this post-e.p.a. world.

Here's an excerpt stolen from the excellent "Captain Norton's Notes" web page.

Take a spray can of carb clearner and poke the nozzle in the idle adjust screws' hole when the screw is out. When you spray in this hole, fluid should be coming out of THREE other places; one of the large holes on the intake face of the carb, and the two small pilot circuit holes you mention above on both sides of the slide . If not, something is still plugged. Try blowing the cleaner from both directions (back flushing). Often it takes soaking ovenight in a jar of acetone to work things loose. I use a REACH brand tooth brush to clean the body. It won't disolve in the acetone like other brands of toothbrushes will. Keep all rubber o-rings away from this stuff or you'll be buying new ones. WEAR SAFETY GLASSES. The carb cleaner CAN spray all over, but it usually just heads straight for your eyes and face. Make sure there is plenty of ventilation. Please don't try this in the furnace room.

Notice the brass plug on the carb base, under that is the slow running jet .016 dia...blowing air down the hole's simply detours it. Drill a 6.8 hole from the opposite side to break into the mixing chamber , this exposes the jet ,twiddle in a .016 wire to remove any obstruction or crud build up...tap the 6,8 hole m8 and plug with a m8x6 grub screw . Often over looked with latter slow running horror's .

FreeRadical said:

Hello all,

It's time to put together the carbs today. As usual, I have more questions. I have included some pictures to help explain...

I received my carb refresh parts today including the manifold seal. The previous insulators are made of some kind of perforated metal; however, the new ones look to be made of a completely different material. The Andover parts fiche has two part numbers (067842 and 063458). I'm not sure which one I have, but I assume I just razor-blade the old ones and use the replacements.

My other concern is regarding differences in the LH and RH carb. The LH carb seems to have MUCH better air flow from the two tiny holes in the carb body (pilot mixing chamber?) than the RH when I shoot my compressed air into the gas intake hole (see pic). I have cleaned and prodded the living daylights out of all orifices. I even bought the tiny .016" drill bit to clean out the fixed pilot jet. I've even shot carb cleaner directly into the gas intake hole. I've spent HOURS cleaning this thing. Should I be worried that the two don't act identical?

Again - thanks for all the advice!

Click to expand...

FreeRadical said:

Hello all,

I even bought the tiny .016" drill bit to clean out the fixed pilot jet. I've even shot carb cleaner directly into the gas intake hole. I've spent HOURS cleaning this thing. Should I be worried that the two don't act identical?

Click to expand...

So are you saying you are able to poke the .016 drill bit through the mixing chamber and through the fixed pilot jet orifice from the air screw hole?
Or are you hitting a blockage in the pilot jet?

Years ago I bought a K+L carb jet cleaner tool. The little rods are knurled and have rounded tips to prevent jet damage. $15.

This will show how to clean the carb and how to access the pilot jet and then install the blanking screw. A lot of good info here.
Pete

Deets55 said:

http://www.jba.bc.ca/Bushmans%20Carb%20Tuning.html

This will show how to clean the carb and how to access the pilot jet and then install the blanking screw. A lot of good info here.
Pete

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I've read a lot of recommendations about drilling out the plug to clear the jet from the gas circuit side but I'm confused about why this is any more effective than probing from the air screw side. It's marginally closer access to the pilot jet, I understand that, but drilling into the side of the carb near the pilot jet is precise work, and seems risky to me.
At a minimum you'd need a drill press and a fixture for accurately holding the odd shaped carb squarely. Then you'd have to tap the hole for a screw. All this without touching the pilot jet, or accidentally blocking the gas circuit. Have you ever actually done this? I'd love to see pictures. Is it really just a thin plug or are you drilling through significant amount of carb body material. Sorry if I'm being dense.

I thought as much on the manifold seal. Thanks.

Regarding the carb...

Yes, I can get the tiny drill to go all the way through the brass fitting inside.

I tested for any blockage by shooting carb cleaner into the pilot jet. Fluid comes out all three holes, as you described.

I can get a strong flow of through the mixing chamber by blocking all of the holes except for the gas intake. I think this proves that there is no blockage between the gas intake and the mixing chamber.

Kevin

FreeRadical said:

I received my carb refresh parts today including the manifold seal. The previous insulators are made of some kind of perforated metal; however, the new ones look to be made of a completely different material. The Andover parts fiche has two part numbers (067842 and 063458). I'm not sure which one I have, but I assume I just razor-blade the old ones and use the replacements.

Click to expand...

Part numbers 067842 and 063458 are carburetor heat insulators that fit between the head and the intake manifolds. They are made from a phenolic sheet and these parts do not come with your gasket sets. You need to order them separately from your Norton parts supplier. Part number 063458 has a 32 mm hole and the 067842 has a 30 mm hole. The opening at the head is 30 mm so I would suggest using 067842. However the larger hole part 063458 would work as well. This insulator is not a gasket and it's reusable. For my bike I use a thin smear of sealant called Fuel Lube (which used to be commonly used in the aircraft industry) on the insulators.

PeterJoe,

Can you tell me what the paper-like manifold seal is and where it goes? Some gasket sets you see on e-bay come with or without this piece. I can see no other place in the parts diagram where this seal would go.



Thanks,

Kevin

Correction: the manifold gasket is more like a rubbery material - not paper.

FreeRadical said:

Can you tell me what the paper-like manifold seal is and where it goes?

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It doesn't belong anywhere on a Commando, because as PeterJoe said, it isn't the right part.


Item [1] or [1A] (link) should be either a 30mm or 32mm phenolic heat insulator.

http://www.nortonmotors.de/ANIL/Norton% ... &Plate=012

L.A.B. said:

FreeRadical said:

Can you tell me what the paper-like manifold seal is and where it goes?

Click to expand...

It doesn't belong anywhere on a Commando, because as PeterJoe said, it isn't the right part.


Item [1] or [1A] (link) should be either a 30mm or 32mm phenolic heat insulator.

http://www.nortonmotors.de/ANIL/Norton% ... &Plate=012

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..and it's much thicker than a paper gasket. Like 1/8" thick as I recall. I can't tell from your picture how thick the new insulator is. The last set I ordered from Old Britts didn't seem like phenolic material to me, but my old ones were. I think there are variations made of some other material nowadays. ( never used them because I installed PWK flat slides ).

mschmitz57 said:

..and it's much thicker than a paper gasket. Like 1/8" thick as I recall. The last set I ordered from Old Britts didn't seem like phenolic material to me, but my old ones were.
I think there are variations made of some other material nowadays.

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3/16" thick phenolic insulators are available from Amal (Burlen).
http://amalcarb.co.uk/catalogsearch/res ... eat+spacer

FreeRadical said:

PeterJoe,

Can you tell me what the paper-like manifold seal is and where it goes? Some gasket sets you see on e-bay come with or without this piece. I can see no other place in the parts diagram where this seal would go.

Kevin

Click to expand...

Ah, I see now. That paper gasket came with your carb rebuild kit, right?
Not sure what this is for. I suspect it's used between the carb and manifold (O-ring) but this is a belt and suspenders approach.
Perhaps for Triumph, BSA, applications.