Triumphrat

Plewsy · 06-28-2009, 08:59 PM

My mate gave me a set of carbs (930'S) they are 66 vintage and have not been used for years. Hoping they would be better than my originals I gave them a service and flattened the bowls and flanges, set the float heights and spent hours poking at the pilot jets. any way here's the run down.

Kev_England · 06-29-2009, 04:43 PM

Plewsy -- great videos!

I am just about to service my carbs. Parts just arrived direct from Amal. Im basically replacing all the parts on my original 68 Amals.

I didnt use any wire to clean out any holes, instead, I dumped the carbs overnight for a soak in Berryman's Carb cleaner (not sure if you get that stuff in the UK). From what I hear itll clean out all the orifices without a need to use wire.

Great idea to use the grinding paste to level the flanges.

What type of paper was you using to initially rub the flanges with?
What was the grinding paste? (The only paste I see over here is this valve grinding paste: http://www.acehardwaresuperstore.com...d-p-69571.html)

I'll be putting the carbs together tommorrow so will be watching these videos again.

Cheers,
Kevin

P.S. just thought about the float height adjustment - can this be achieved by bending the tab on the carb? Maybe my carbs are a little different than your in this regard?

Plewsy · 06-29-2009, 09:11 PM

Hi n thanks Kev_England, a full rebuild on your own carbs great, plenty of time they need to set up and adjust, I found the tiniest of turns on my air screw makes a big difference.

I have not heard of Berrymans but there are other carb cleaners over here, I have used a few, good yes, but they have there limits, sometimes a bit of wire or a drill is the only answer.

Yes the grinding paste I use is valve lapping paste, a tin with two lids, fine one end coarse the other. The paper I used was 120 grit wet or dry Carborundum paper.

I have seen the plastic floats with the metal tabs, me I would leave them be, and adjust the seat!
Keep us posted

pochie · 08-14-2009, 10:33 AM

Hi. Thank you for your opinions. I am going to dismantle and clean. Your videos will be very helpful. I am going to get a chrome slide as I hear they last, virtually forever. Have a good weekend! Pochie

cafetbird · 08-14-2009, 03:27 PM

That was a nice video - will come in quiet handy for many a new vintage rider.

I just used varied grades of sandpaper for leveling things off.

A nice thing to get for carb cleaning is a ultrasonic cleaner. You can pic them up at shops like Harbor Freight for less than $100 bucks. They care care of grunge in all the nooks and crannies...

sangalfie · 02-02-2010, 01:13 AM

Great help Plewsy! I just finished a top end overhaul, and about to reinstall my carbs. Couldn't figure out how to put the needle and spring back in place, so decided to check this out.

One question, the metal washer that attaches to the needle...does it matter which groove (on the needle) it's tacked on to? Seems there are 3 settings (bot/mid/top), and wanted to get it right the first time.

Plewsy · 02-02-2010, 09:19 AM

Hi sangalfie

I'm just finishing of a replacement head for mine, new guides and valves and its looking good

but digress, back to your carbs, you should use the middle groove on the needle at first,
you might get it right first time but only a run on the bike and plug chop will confirm.
Some needle clips also hold the cable in the slot they are a pain to fit but are the best,
the slide spring also presses onto this clip.
I'm glad the vid was handy, did I not mention the needle position?

sangalfie · 02-02-2010, 11:56 AM

Plewsy,

I believe you did mention the needle position...but figured there was a reasoning for these 3 positions. I will go ahead and place it in the middle for now...and will fire it up this wknd

How will I know after I run the bike if it's in the correct position.

What is the cause & effect of this...

Plewsy · 02-03-2010, 11:51 AM

Hi sangalfie

,
the three slots in needle are for changing the fuel/air mix
the top slot (needle highest in the jet) = a richer mix, black plug.
the middle slot (needle centred in jet) = std position, good plug (hopfully

)
the bottom slot (needle lowest in jet)=a weaker mix, glazed/white dotty plug.
The needle controls the mix of fuel/air around 1/4-3/4ish throttle position.

Symptoms of a weak mix on the needle are spitting PoPing from the carb
usually when opening the throttle, it might settle down (slightly weak) or do it all the time (very weak).

If not corrected a weak mix all jets included will overheat the engine and devour the piston crowns.

Precursors to piston failure would be a glazed white plug, overheating, pinking, loss of power.

A rich mix on the other hand is not as bad, the biggest danger is petrol flush.
Symptoms of a rich mix would be a black sooty plug, lack of power,
poor throttle response it may give signs of a slight miss fire.
A good starter when cold hardly needs choke and a bad starter when hot, opening the throttle can help make it start.

Clean your plugs and if non of the major symptoms above are apparent, go for a ride
do a few normal miles, whip your plugs out and check the colour,
do a few more miles at a set throttle opening and check the colour.

I have noticed with the modern fuels plugs tend to look a bit whiter
than they used to,
what you don't want is a glazed shiny white electrode usually accompanied with grey dots
(probably specks of piston.)

With standard jets and factory settings on a standard motor
most of the above is unlikely and only fine tuning to suit conditions will be required

sangalfie · 02-03-2010, 12:04 PM

Great info once again!

I installed my carbs and finally put my tank on last night...

These are my carbs installed w/ the throttle cables attached...I noticed that the opening gap is huge (and not the recommended "guitar string gap"). Is this a needle adjustment or a cable adjustment. Thought I'd ask before I start touching either components.