Amal carb problem...

Need some help on troubleshootin a carb problem. Bike is a 69 lightning with boyers.

My right hand amal blows mist back when I snap it. It is only the right side that seems to do this. I once read that this is a lean issue.

The other night I took the bike for a test after assembly and it chugs along fine but will get the odd bit of hesitation under throttle. By the time I got home, the carbs were hot as hell and the left slide actually stuck open when I pulled in to the drive. I have the intake spacers intake with rubber O ring. Te plugs are showing black and bit sooty but not particularly wet.

I have removed both carbs and cleaned them, checked all connections etc. Cleaining included disassembly, boiling, carb cleaner, probing the cicuits, more carb cleaner, and blowing afterwards.

The bike starts first kick and idles fairly well, chokes function correct and I am starting with 1 1/2 turns out on the mix screws. Have tried running the right carb with only 1 turn out and it still mists.

I would appreciate your thoughts/recommendations as I am running out of ideas here!

Try running it with the right carb with the idle adjustment screw right in.

If it still runs, as we suspect it might, it has an air leak somewhere.
Manifold. ?
Worn slide ?
Worn valve guide ?
Or the idle circuit is blocked, and its idling on the needle jet....

If not, more suggestions.

Cheers.

The bike will run on left cylinder allone so dialed up the right throttle stop and pulled the lead off the left side. Bike ran on right only. Screwed in the mix and it killed it.

Tried spraying carb cleaner on the intake but no improvement noted.

The mist even comes out on a dead kick. Can't see it when the bike is running at higher throttle but definetly there each time you jolt it from idle.

Er . . . swapping carbs from side to side would tell you what side of the manifold it was, for the moment ,
One pressumes the ignition is checked and set perfectly before setting carbs .

Righto. Have you tried setting the idle on the right side just winding the mixture screw in and out, see where it runs best.

Checked the inlet valve clearances ?

When you ease it over compressions with the kickstarter, slowly, can you hear any hissing ?
If a valve is not seating too well, and leaks, it might do this.

P,S. May be worth trying this with a new set of sparkplugs installed.
Or just a new one on the right side.
They are not immune from this sort of problem...

I checked valve clearance and seemed ok. Tried bumping the needle up a notch but no solution there.

I did play with the needle but no real joy either way.

I am going to try replacing the needle and main jet (the needle does look rather blunt).

While I am a it I will replace the intake gasket (which is separated into two pieces) and trhow some new plugs at it

I will run down to the local shop tomorrow and post up if I get her going good again.

It ran like a champ all last year!

Thanks guys!

Well swapped out the needle and jet on the right carb. Replaced the intake gasket. Still no real difference in that the carb blows a mist back when it transitions from idle to hi speed circuit. Idle is fine and starts first kick with prime.

Maybe this is just a normal transition?

I did check compression and the pressure seems fine. I go plugs out and 5 good kicks per side. Compression was 120ish - L/140ish- R

Have you dropped the needle a notch (raising the clip one groove).

Check timing. Possibly retarded.

Tried dropping the needle but no real change I could discern. I have Boyers on it so I woudl think the timing should be ok unless the stator moved but doubt it would have.

Thanks

Amal , ? AMAL ! you ! want Amal ! ?

http://archives.jampot.dk/Technical/Car ... Manual.pdf .

There . That should do it .

One thing with TWO Carbs . Theyre ONE Carb . :shock:

Ideally , treat both identically , not as this and that . Or they WONT work IDEALLY .

Its actually quite basic , just twice the endevour . The gains tend to be high flow .
i.e. top 1/3 r.p.m.s , the bothers tend to be bottom end of powerband .

As SOMEBODYs been fidleing . Treat em right ,set stops identical ,
then cable free play .Twin Cables are to be preferred for instantaeneous response.

Jetting from the Top , W.F.O. is the recomended method.If youve overcome youre hamfistedness.
Otherwise its liable to get expensive.

ROVER 75 Manual recomends " Remove Air Cleaner , warm Engine . Run Full Speed .
Pull Choke cautiously . If speed increses , its set lean. :cry: If speed decreases , its set rich ".

Apparently dynos are notorious for inadequate jetting on new engines .Gave the garage at the top of the causeway
were we tested the Rover this advice ( tounge in cheek ) talking about there new Cosworth Capri 3100 engine .


" Blough Blough ! These Days were more tecnical , we use a dyno , its all electronic "

visited again to tell em where a few capris were hideing in the bush, There were two old blokes
in the corner muttering about the melted piston in the new Cosworth Capri 3100 engine . oh dear .

there car had ended up in a paddock via a fence post . :shock: They dont makem like they used too . :roll: