Worn Amal 932 problems - advice please!

[Kim275]

Hi All

Getting the MDS ready for next season's assault . Bike is up in the midlands with my Dad , he stripped and cleaned the carb - and advised the slide/carb is worn. He measured a gap of about 1.5mm. The Carb was fitted new for the 2008 season and has has 6 season's of pretty hard racing . It is a 32mm 900 series and was purchased form Hitchcock's to replace the original monoblock - and has the standard carb slide (not brass or nylon) .

Question 1. I assume that this would leak air and run lean on lower revs ?. (note The bike suffers form overheating and slow pick up after a few laps...am wondering whether this is part of the problem?)
2. Would both the slide and body have worn ? - so I need to replace the carb? - or can i try just replacing with a new slide?

If i need to replace - and knowing a lot of previous conversation about poor quality of the replica Amal's - what is the best option in terms of sourcing?

Cheer for any advice/experience you guys have.

Cheers in advance Kim

[Andy Z]

Hi All

Getting the MDS ready for next season's assault . Bike is up in the midlands with my Dad , he stripped and cleaned the carb - and advised the slide/carb is worn. He measured a gap of about 1.5mm. The Carb was fitted new for the 2008 season and has has 6 season's of pretty hard racing . It is a 32mm 900 series and was purchased form Hitchcock's to replace the original monoblock - and has the standard carb slide (not brass or nylon) .

Question 1. I assume that this would leak air and run lean on lower revs ?. (note The bike suffers form overheating and slow pick up after a few laps...am wondering whether this is part of the problem?)
2. Would both the slide and body have worn ? - so I need to replace the carb? - or can i try just replacing with a new slide?

If i need to replace - and knowing a lot of previous conversation about poor quality of the replica Amal's - what is the best option in terms of sourcing?

Cheer for any advice/experience you guys have.

Cheers in advance Kim

Hi Kim,

I would say that 1.5mm clearance is a tad excessive!

Unfortunately, the carbs seem to wear just as much as the slides, so it might mean a new carb, but I would try a newer slide in there first before dumping it. The standard slides are very soft.

Martin Bratby can ream the carb and make a new slide, but this would probably be more expensive than a new carb.

The Wassell carbs are supposed to be quite good, and are cheaper than the Amals, might be worth a go. I'm sure someone on here has used one.

Cheers,
Andrew

[gribley]

If the class rules allow, fit a Mikuni VM.
If not get a new Amal fitted with the chrome plated brass slide. The standard slides are so soft, microscopic dust particles (small enough to get through the filter) embed themselves in the slide and carve away the body

[Kim275]

Thanks for feedback

Guys,
Much appreciated - and explains why this carb has worn so badly....... and teh bike performance....

For this one VM Mikuni not an option - so will go with a new Amal 932 with chrome plated brass slide.........

anybody had any experience with the Wassel version?
Cheers Kim

[John Pattinson]

Amal Carbs

I do know Wassell only sell them as the four stroke version but you can convert to two stroke quite easily. Be careful with worn carbs as the slides hammer and break up and then end up wrecking the engine, try to buy new!

[Andy Z]

Just something you might want to bear in mind, Amal 600/900 carbs are now made in China, and the Wassells are made in Taiwan. I think many people buy Amals thinking the are made in the UK.

[Kim275]

Good Info! Thanks John and Andy

And we used to be worried about the spanish versions of the Amal 1000 series !
I am thinking of going back to Surrey cycles - as have always got stuff set up correctly by them and good quality......but probably the same improted stock as the ones you get from Hitchcock's

[Andy Z]

And we used to be worried about the spanish versions of the Amal 1000 series !
I am thinking of going back to Surrey cycles - as have always got stuff set up correctly by them and good quality......but probably the same improted stock as the ones you get from Hitchcock's

At least if you order it from Surrey cycles you might not have to wait 16 weeks for it. Last time I looked on the Burlen website that's what they quoted as a lead time!

[Kim275]

At least if you order it from Surrey cycles you might not have to wait 16 weeks for it. Last time I looked on the Burlen website that's what they quoted as a lead time!

I assume 15 weeks to explain to the chinese manufacturer the english drawings and convert Inches to mm etc .....a Friday afternoon to make 4,000 of them and a week to ship/add an extortionate mark up and deliver !!

[Phil Hyde]

Carb wear.

I fitted an anodized slide in my 626 concentric. It is a nice bit of kit. A tad expensive with the added bonus of being round!

I have a Mikuni to try when I find the time.

[scott151]

It was me

Hi all,

I was the one who bought the wassell 932, I got mine off Terry Sewell, I had a job getting the bike to start at first with the carb in standard settings, I switched the needle jet to 107 from 106 at john aspreys advise, and hey presto, bikes superb now.

What I have to say is the wassel is well made with die cast fittings, the genuine Amals have plastic fittings..

As to the Mds Kim, I run a 930 on mine, dads a 932, but dads is in a higher state of tune than mine, but my bike is much quicker out of the corners and does not bog down. I was thinking of changing mine to 932 to boost top end?

A lot of how the bike performs is down to the exhaust... No two bikes are the same...

Scott

[aa will]

the wassell version is a good bit of kit ,i have supplied and fitted about ten in the last year with no problems with the carbs ,you just have to play with the settings to get them spot on ,wassell also supply hard anodised slides now which you have to buy as an extra ,it still works out cheaper than amal ones i run a 930 on my trials outfit which uses a 34a barrell and h/c head works really well , will.

[Rob]

I had a lot of trouble getting a decent Amal from a well-known carburettor supplier. The first had more tolerance on the slide (at least 5 thou) than the old one and looked like it had been machined with a blunt half-brick. Strangely enough, the 'technical department' did not have 'the figures to hand' for the slide tolerance which said a lot.

Supplier grudgingly took it back and then returned it in error to the retailer I bought it from and left me to sort it out. Slide fit was only marginally better and machining not touched so I showed it to supplier at Stafford who said 'that's not very good, would you like us to take it back and sort it out for you?' I explained it had just (eventually) been returned from them! Shock, horror, back it went. I could not tune the pilot on the replacement and when I took it apart, the pilot jet was half unscrewed. When I tightened it, the bike just would not start but was first kick with the old carb.

Back it went again and this time I asked for a 'premier' replacement. Despite all my problems, they were adamant they wanted more money for this but they eventually relented. Once I got the carb, I took out the pilot jet and screw and could not see through the hole. The 'technical department' once again demonstrating their incredible prowess, did not appear to know if you should be able to see through it or not.

With gentle teasing and use of carb cleaner, I eventually extracted enough swarf to cover a finger nail. I photographed this and mailed the image to supplier. I followed this up with a phone call and supplier admitted 'we may have a quality control issue'. Really!?

In the end, the carb worked but it took from getting the carb at Telford in February, via Stafford in April until about June.

The only thing that really wears on the carb is the slide / bore. Rather than buy a Chinese Amal, I now clean the bore in the lathe which involves removing very little metal. I then make up a slide from aluminium bar to suit. Costs me nothing and it works. I started writing it up in Leading Link and must get around to finishing it.

I haven't tried making a 32mm version yet so if you care to let me have your old worn carb Kim, we can give it a try.

Thought I'd better just add, I am NOT referring to Mick at Surrey Cycles, he is OK!

[Kim275]

Hi all,

I was the one who bought the wassell 932, I got mine off Terry Sewell, I had a job getting the bike to start at first with the carb in standard settings, I switched the needle jet to 107 from 106 at john aspreys advise, and hey presto, bikes superb now.

What I have to say is the wassel is well made with die cast fittings, the genuine Amals have plastic fittings..

As to the Mds Kim, I run a 930 on mine, dads a 932, but dads is in a higher state of tune than mine, but my bike is much quicker out of the corners and does not bog down. I was thinking of changing mine to 932 to boost top end?

A lot of how the bike performs is down to the exhaust... No two bikes are the same...

Scott

Scott - many thanks for chipping in .............. worth trying a 932 to see what the difference is - but clearly the exhaust will be a big factor as well (suggest you just swap your Dad's carb next time you are round for family Sunday Lunch )

[Kim275]

Will and Rob thanks for our advice

re carb re-fettling - it's up in the Midlands but a very kind offer Rob - will drop you PM

RE all the problems with New carbs..........unbelievable !!