Jet replacement kit

Status
Not open for further replies.
Lineslinger

Lineslinger

VIP MEMBER
Joined
Feb 26, 2017
Messages
1,674
Country flag
I am looking for a supplier that offers a package of replacement jets for a set of Amal 932’s, L 36 & R 35. 1974 850 Commando.

Or, do I have to purchase each one individually or in pairs?

The carbs have been overhauled completely and the original jets thoroughly cleaned along with new slides floats, gaskets etc etc.. The engine is running rich but smooth.
And the setting of the adjustment screws make zero sense when using a vacuum gauge to try and get them close.

I am reworking the head and while the carbs are off I want to replace the jets and needle so I know when tuning begins any variable of a worn jet/jets is off the table.

I don’t need an overhaul kit but an original spec jet “kit or package” to get this engine in decent running order before putting it on the dyno.
Not looking at new carbs at this time...I can make these work....eventually.

Edit:
40 views no response, guess it’s a piece by piece purchase.
For those who have done their fair share of Amal tweaking, does this selection sound solid as a start point?

Main: 220
Pilot: 25’
Thrtl. Vlv.: 3
Needle Jet: .106
 
Last edited:
Lineslinger said:
I am looking for a supplier that offers a package of replacement jets for a set of Amal 932’s, L & R 35. 1974 850 Commando.

Or, do I have to purchase each one individually or in pairs?

The carbs have been overhauled completely and the original jets thoroughly cleaned along with new slides floats, gaskets etc etc.. The engine is running rich but smooth.
And the setting of the adjustment screws make zero sense when using a vacuum gauge to try and get them close.

I am reworking the head and while the carbs are off I want to replace the jets and needle so I know when tuning begins any variable of a worn jet/jets is off the table.

I don’t need an overhaul kit but an original spec jet “kit or package” to get this engine in decent running order before putting it on the dyno.
Not looking at new carbs at this time...I can make these work....eventually.

Edit:
40 views no response, guess it’s a piece by piece purchase.
For those who have done their fair share of Amal tweaking, does this selection sound solid as a start point?

Main: 220
Pilot: 25’
Thrtl. Vlv.: 3
Needle Jet: .106
Click to expand...
The needle jets wear, maybe the needles a little, but there shouldn't be any wear in the mains. The idle jet is usually a pressed in bushing drilled to about .016" if I remember correctly. If you have a screw in idle jet that's a whole different ball game.
 
Yes needle jets wear causing richness.
Float needles tips go sketchy with age too causing richness.
 
B+Bogus said:
Anodised slides are a good investment too
Click to expand...

Indeed. If buying slides anyway, it would be daft not to frankly!

But, @ Lineslinger, before investing too much money in these old carbs you should at least e sure the pilot circuit is not clogged with decades of crud...
 
I use Mikuni needles which are hard anodised,in my Mk2 Amals. Because I run methanol, I make my own needle jets which are currently 0.116 inch diameter. If they are 0.117 inch diameter the motor is slightly sluggish when I accelerate. So considering the needles can be raised or lowered, the difference in jet diameter is about half a thou of an inch between good and bad. When you run your Commando on petrol, you normally use either 0.106 or 0.107 inch needle jets and you need about half the flow which is needed with methanol. So the difference between good and bad when using petrol, is about a quarter of a thou of an inch wear in the jet. When using methanol, you can make your own needle jets by using a combination of metric and number drills. With petrol you would probably need to match jet sizes using a flow meter. I don't know whether I would trust Amal's quality control. With petrol, getting it right is absolutely critical if you want performance.
If either float bowl is flooding or has incorrect fuel level when you are tuning, it is back to square one - start again.
 
In Australia in the 1950s, we used to race using methanol fuel. When our guys raced in the UK, the found the British got their Manx Nortons going as fast as those in Australia, using petrol. I'd never race using petrol, it would drive you insane.
 
Except for s/s ¼ & M/c speedway, the ACU in the UK do not allow any other fuel other than petrol, so, are you calling us all insane?
 
I run 260 mains, (sea level) helping to compensate for ethanol fuel. Clean plugs across the range.
 
Lineslinger said:
I am looking for a supplier that offers a package of replacement jets for a set of Amal 932’s, L 36 & R 35. 1974 850 Commando.

Or, do I have to purchase each one individually or in pairs?

The carbs have been overhauled completely and the original jets thoroughly cleaned along with new slides floats, gaskets etc etc.. The engine is running rich but smooth.
And the setting of the adjustment screws make zero sense when using a vacuum gauge to try and get them close.

I am reworking the head and while the carbs are off I want to replace the jets and needle so I know when tuning begins any variable of a worn jet/jets is off the table.

I don’t need an overhaul kit but an original spec jet “kit or package” to get this engine in decent running order before putting it on the dyno.
Not looking at new carbs at this time...I can make these work....eventually.

Edit:
40 views no response, guess it’s a piece by piece purchase.
For those who have done their fair share of Amal tweaking, does this selection sound solid as a start point?

Main: 220
Pilot: 25’
Thrtl. Vlv.: 3
Needle Jet: .106
Click to expand...
 
Amal # 622/235 Is a update kit for early concentrics. It includes a new needle, 2 rings. a 106 needle jet and a new jet holder.
The new stay up floats, easier to adjust float level, are nice to have along with Amal # 622/197al alloy float needles.
 
Status
Not open for further replies.
Back
Top