Yes another Carb refreshment post

[E.Marquez]

Yesterday I had a slight stumble at idle and also occasional on rolling on the throttle. More than 2 years since last cleaned and 5 weeks sitting as i had other bikes to ride allowed the pilot circuit build up some blockage. Decided instead of just a quick fix for that, Id do a total refresh on them.
Full dissemble, inspection, dip in the sonic tank, inspection then reassembly using all new O rings, Silicone hose and Oetiker clamps for the Air cut off valves. Silicone hose for the rest of the vac lines using a mix of Oetiker clamps on the ends that do not see normal removal and embossed full circle clamps made for Silicone hose.. Silicone hose for all the carb coolant, vent and fuel lines more Oetiker clamps, some Gates PowerGrip SB Heat Shrinkable Hose Clamps and a few zip ties...

Disassembly went as normal, what some may not know about are the small and likely hardened and leaking

o_ring_6eac429409ceff79a540a3cf462825c568ef1d11[1].jpg (27.87 KiB) Viewed 4826 times

And there are more..... each one a potential leak, each one potentially damaged when you use "Carb Cleaner" And only Penney's to replace.
Do it right
Do it once
Initial inspection looked good, no wear in the needle jets a part technically non replaceable, though I have a source for them and new ones can be made then fit in the carb bodies.

Off to the Sonic tank for 30 min bath

And all clean, inside and out.

Parts you say? Why yes parts
4 each O-RING (1.3X4.3)
16075-GHB-640

2 Each GASKET SET
16010-HM7-670
2 Each GASKET, FLOAT CHAMBER
16163-MBB-640

2 Each
O-RING
16076-MBB-640

2 Each O rings for the fuel screw Which are not available as a single service item for this carb, but can be had in same size (same part) in other bike models or bought bulk as I do.

2 Each
GASKET SET
16040-MBB-640

And then Silicone hose for everything you wish to replace... for thats every MM of black rubber hose in use now.

Post cleaning second inspection reviled this set of carbs is in very good condition with almost no visible or measurable wear. So other than being 18 years old and a bit dirty they are prime for full refresh as no machine work is needed, throttle shaft seals are good.

Decided to replace the intake manifolds as they were getting a bit hard. I thought I had replaced them already but they appear to be the originals.

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Things are on hold while those come in as well as a second set of GASKET SET 16040-MBB-640 (all item #6 come in one set, per carb, so you need 2 each sets for full build)

Why you might ask do I need another gasket set???????? because one of my dogs ate the paper bag and both sets of O rings I had in them..... Of our 5 dogs, He is the only one that truly likes to hand out in the shop with me...but the damn beast occasionally decides to eat paper tows of other "trash" he can reach. And the bike lift the parts were on was at floor level....lol,,,,I know better then that.

while I wait to go pick up parts that came in this morning I did some basic clean up and refurbishment
Metal work was a bit corroded form yeasr of being in the air and general environment.

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So it got a quick polish careful to not burn through the the zinc plating which does provide rust protection

All rubber hoses (and O rings, gaskets and packings) are being replaced.
Hoses are being replaced with HPS silicone hose, the spring clamps replaced with either perfect circle oetiker clamps like this

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Or Gates silicone hose clamps on the coolant lines



They are designed so that they have no cutting edges to damage soft (silicone) hoses

[E.Marquez]

Redid the vacuum lines as well for petcock and carb balancing

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The vacuum valves (slides) were looking a bit rough even though only about 1 and 2 years old (rear is older, front replaced last year when the diaphragm was found with a hole in it)

That was the "better" of the two in the carbs and better than all 5 I had on hand.

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Three stages of plastic polish and they are clean and smooth again. They slide in the carb body noticeably easier, though that may diminish as the polish wears off.

Considering having some new ones coated with a hard wearing coating that is also a lube.


The rest of the O rings and the new carb manifold boots are in, I just have to take a 60 mile trip and go get them... Friday i think

[fabiostar]

A pain of a job to do but well worth it

[KermitLeFrog]

Impressive!

[sirch345]

Those hose clips look brilliant

Good work

Chris.

[E.Marquez]

On another site I was asked out carb balancing lines and after I posted I noticed the plugs made for the lines were a bit beat up

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and the small end was a pain to grab and remove from the silicone hose, came right out of the rubber vac line.
So off to the lathe I went..

Nothing fancy, just basic and works... the end has some knurling, is a bit larger and is easier to remove from the sticky silicone hose.

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Now I just need the rest of the parts sitting at the shop waiting for me.....

[E.Marquez]

Those hose clips look brilliant

Good work

Chris.

Thanks
Oetiker clamps are really a good hose clamp as they form a 360 deg clamp on the hose, have no cutting edges to damage the hose and are usable on the smallest of hoses unlike worm gear clamps and as long as you use the correct size provide constant tension as the hose expands and contracts form heat or pressure.
The down side of course is, they are not reusable nor as easy to loosen as other types of clamps.
But things like vacuum lines on the head, carbs or coolant lines at the pump and thermostat that will not be removed often or at all unless major work is being done... why not.

Another nice non standard "clamp" I have been using in some applications is made by the US company Gates
https://www.gates.com/us/en/fluid-power ... /p/p100748

They are a heat shrink tube and make a perfect 360 seal, wider then common clamps and once installed have a very clean appearance.. they also are very "low" clearance and Ive been able to use then in a few applications where space between the port and installed hose next to a manifold, or other part was very limited and the large worm drive or T bolt of other clamps would have been difficult to use.

Like the Oetiker , the Gates Powergrip Sb clamp has down sides...Not reusable, has to be cut off (super cool little tool that cuts the band no risk to the hose) can not be used in ultra high heat applications... though low pressure line next to a turbo on my Shelby GT500 Mustang has not been an issue

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[tony.mon]

Now they're neat, and look as good as they should work..
Hmmmmmmm, might have to renew some hoses...

[AMCQ46]

i like those heatshrink clamps, that is a nice idea for low pressure pipes

[sirch345]

I meant to say in my last post how fantastic your carbs look now they have been cleaned, along with the other polished parts, they look like new, well done

Rather intrigued by your Oetiker clamps, how they clamp 360 deg around the hose and no sharp edges to damage the hose, that makes their design brilliant in my opinion. Looking a little more into them, I see they can be purchased with a screw thread making them re-usable. As you say though, that wouldn't be necessary for most of the hoses on our bikes, although could be helpful for the main radiator hose(s) that need to be removed for coolant drain downs.
https://www.ebay.co.uk/itm/Oetiker-1780 ... ctupt=true

Now to find a local supplier who doesn't want to sell me boxes of them

I also like that heat shrink type of hose clamp, especially how the special tool allows removal without damaging the hose.

It's surprising what you can learn on a motorcycle forum

Chris.

[E.Marquez]

It was a 10 second task....................And then it wasn't
I was putting carbs back together

Just needed to screw in the idle adjuster
10 sec max......until the black plastic knob breaks
in two

I considered making a mold and pouring a new know from Epoxy, but that seemed more work then i wanted to do tonight, and really did not need a adjuster knob with insulation properties...just a darn thing to grab onto and turn the screw.

So a hunk of 7071 3/4" rod I had on hand got tapped for duty.

Turn to size, knurl the end

Chamfer the end

Drill the through hole .003 undersized to the screw shank, pocket bore the knob undersized .003 for the head of the screw, Start the part, then chamfer the lower edge.

Finish parting the knob from the stock and press in the adjuster screw.

and there you are, a 10 second task that took me an hour...........

[Beef]

That is bloody lovely work

[E.Marquez]

Got a little farther, cleaned the linkage up, picked though the available plastic washers and chose the best ones...
Installed the linkage

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Dont forget there are two different style plastic washers on each pin plus a steel one.
The plastic washer that is split and convex shape goes on first, it helps space the linkage bar away from the link arm, it acts as a "spring" as sorts for lateral play, and reduces friction surface area..
Then the link goes on, then flat plastic washer, steel washer and cotter pin.
NO oil or grease... this link uses a bronze bushing so no lube is needed and lube like that will make things worse as it would attract dirt and other abrasives. If you want a dry lubricant can be used, but still not really needed so if you don't have some Teflon or moly dry lube, no lube is better (don't hear that often now do you....)


Setting the TPS is fast and easy if you have a test cable made up.. Nothing more then a piece of the OEM harness sectioned out..I had an old harness on hand so made the cable... Otherwise meter test leads with clips on the end to hold on to the TPS pins works as well.

As stock, this TPS was set to 787 Ohms and the lowest the TPS could be adjusted to was 656 ohms

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With just the steel bushing removed it could be adjusted to 526 ohms

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I removed 2 mm of material from the TPS and tested, it was 398 ohms... showing that very little material need be removed...about 1mm or so
With the TPS set at 500.4 ohms you can see here how little more travel is needed in the adjustment travel

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You can remove the steel bushing, file out about 1mm of plastic and put new screws in without the bushing.. The bushing is there so you do not damage the TPS when tightening. So, don't over tighten the screws, just snug them up....and use a drop of medium strength thread lock to keep the "under" tightened screws from vibrating out. I have a few dozen bikes with 10's of thousands of miles running that way no issue at all.


But lately I have started retaining a part of the bushing... Simply because Im not the only one that might be wrenching on the bike after me (not this one specifically, but in general)
So trim the TPS as needed to get your preferred setting, then trim just one end of the bushing that covers the needed additional adjustment range,,,Only a corner of the bushing needs to be trimmed..retain as much as you can.

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I do not believe there is an perfect setting, but an ideal range ..someplace between 490 and 600.
My 98 ran best at just below 500, the 2001 right at 500, but others have reported best for their bike at 520, 520, 560.
So pick a number say 500, set it, and test on a fully warmed machine try a few other settings and see what your bike likes best.

Button head SS socket screws with a drop of Loctite 222 light thread lock

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And all done, think I got close to my target 500 ohms

[sirch345]

Nice work with the lathe

Thanks for the photo's as well

Chris.

[Beef]

Gread thread, more refernce material than I know what to do with, I have so much to do to my shed.....and so little time!!