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Does anyone have any experience with using a Wassel Evo or AMAL Premier Carbs when fitted to a B44? When my dad fitted premiers to his commandos, he found them very hard to start without using the choke when cold, one of his neighbours with a 73 T140 had the same when he fitted Wassel evolutions. Does anyone know if the same is true with the B44 or B50. I am fitting a Wassel Evolution to my B44 soon, and I need to decide whether I fit the choke or not. Obviously the B44 didn't have a choke fitted as standard but I have a spare lever and cable of my 71 A65 which is under restoration. Any thoughts or help greatly appreciated

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The AMAL premiers are cold blooded despite the 17 premier pilot jet being the exact same size as the old 25 pilot bush, they now fit 19 premier pilot jets to all Commando carbs they supply. It must be something to do with the extra turns the fuel has to navigate so as the Wassell Evolution is an exact copy then they must be the same. So I would go for which ever I prefer but get it with a 19 pilot jet which is the same as the old 30 pilot.

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Originally Posted by kommando
get it with a 19 pilot jet which is the same as the old 30 pilot.
= my experience on B40 with a 626 Premier.


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going back to the original question, choke or no choke.

I fitted new AMAL premiers to both of my B44s. They are radically different states of tune. One has a large valve head, ported, 40 thou over bore, high(er) compression slipper piston, light weight pushrods, lightened rockers, pea nut exhaust.
The other is completely stock.
They have the same jets, needles, and slides and both run just fine.
One carb (the second one) came with a choke, didn't fit it and have not regretted it, though probably would not have regretted fitting it either!
Flooding the carbs and judicious use of the valve lifter seems to work just fine in starting them, though I do have the idle mix a tiny bit (like 16th of a turn) rich. Extended tickover screws are worthwhile, and help reduce the temptation to give it "just a little bit" of throttle while kicking, an absolute no no.

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I have the old Concentric on my B44 and only use the choke for starting when the bike is hot. Cold starting, I screw the throttle screw in about 1/2 turn, flood the carb and start it without touching the throttle. Starts everytime max 2 kicks. I have the longer kick lever which helps.

Last edited by Roadwarrior; 06/19/22 2:53 am.

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Thank you all for the feedback,

I'm not having any trouble starting (from cold) with the orginal Concentric that is fitted at the moment, however it is warped and the slide sticks so i decided to replace it, and was concerned that that could lead to difficulty starting without the choke as my Dad has seen on his commandoes.

I have made the decision to go with a No19 pilot jet at Kommando's and Pelle's advice.

If my issue with hot starting continues I will look at fitting the choke as Roadwarrior has done

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I recently pre-ordered a new Premier AMAL 930/38 for my B44 directly from AMAL in the UK. I have no idea when it will be available. I'm trying to keep it mostly original.

Last edited by Gary Caines; 06/25/22 12:18 pm.

Current Bike: 1968 Triumph Bonneville T120R, 1969 BSA Victor Special, 1975 Norton 850 Commando John Player, M1030M1 U.S.M.C. Diesel
Previous British Bikes: 1968 BSA Lightning, 1969 BSA Lightning, 1969 BSA Firebird Scrambler, 1972 BSA B50 Gold Star, 1974 Triumph Trident
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Originally Posted by SamAdamson
Thank you all for the feedback,

I'm not having any trouble starting (from cold) with the orginal Concentric that is fitted at the moment, however it is warped and the slide sticks so i decided to replace it, and was concerned that that could lead to difficulty starting without the choke as my Dad has seen on his commandoes.

I have made the decision to go with a No19 pilot jet at Kommando's and Pelle's advice.

If my issue with hot starting continues I will look at fitting the choke as Roadwarrior has done

I’d order the carb with the choke mechanism and a carb top blanking screw. Then you can fit or remove the choke as you please. Shouldn’t cost any more if you specify it at the time of order


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The Carb came with a choke as i couldn't find anyone selling a B44 specific one so it came set up for a 650/750 twin, and i was able to repurpose the blanking plug off the original carb so i could do either anyway, And i already had a few spare chokes from the carb of my A65T and a few old knacked 930's my Dad gave me for spares.

However, i had to reuse the cap of my original carb short term anyway as the throttle cable i had a ferrule that didn't fit into the adjustment on the evolution carb, and short term i didn't want to remove it so i reused the original.

It seemed to start well enough without the choke although it did take 4 or 5 kicks however i had just had to replace the coil with a spare of my A65 so the bike was not perfectly set up, I'm currently setting up electronic ignition to hopefully improve how the bike runs.

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The choke is really not needed to get the cold engine started when you do a generous tickle, what it does help with is a cold morning, as the fuel level drops you can use it to keep the mixture rich until the engine is warm. I find it helps more on hot starts but as soon as the engine catches you must turn it off as it 8 strokes and there is potential to foul the plug.

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I managed to get out for a decent ride for the first time since fitting the new carb and VAPE EI, The bike is certainly much better for it, it will now idle and is easier to start (although some of that could be my technique improving).

Only issue now is quite considerable clutch slip, it seemed like anything over half throttle the clutch couldn't cope, I had previously changed the plain plates but now i am going to change the friction plates to surflex types, the bike has been fitted with a B50/4.5 plate conversion in the past so i'm confident with new friction plates and slightly tighter springs i can get the clutch to stop slipping.

I overheated the front brake something fierce, i went over the buttertubs pass from Hawes to Thwaite and bythe time i got to the bottom the front brake had all but faded to nothing and there was smoke coming out of the air vents, some new higher performance brake shoes will also be required

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Overheating the brakes on downhills is not a sensible way to ride on the road. You could lose the use of your life.
Linings that are “harder” and more fade-resistant often have less grip when cool.

If I were you, I’d try to find clutch plates with cork in the lining compound. Low-priced Emgo plates used to have cork. It’s good for grip when oily.

Always assuming you’ve already done all the adjustments by the booK.


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Theres a modification which can be done to the B44 clutch centre, which involves grinding the step off the bottom outer of the clutch centre. you can then fit the same amount of clutch plates as the B50. does yours have this conversion Sam?


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As this was my first log ride over a twisty road on a bike with a front drum brake (the prevous classics i've ridden have discs or needed restoration before a ride over 40 miles could be done) I didn't feel like i was taking much of a liberty with the front brake but clearly i was, The front shoes are old too so they could have degraded over time. the rear brake wasn't well set up so after i had fiddled with that while i let the front cool down i was able to use more rear.

I am a heavy guy so getting heat into the brakes is unlikely ever to be an issue for me so harder more fade resistant shoes will probably be the best way to go.

Clutch adjustments done as per the manual.

Yes Allan, I'm the first UK owner so i have no idea when the conversion was done, but it contains 5 friction plates and 5 plain plates as a B50 would.

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Firstly, .... a front brake that generates enough friction to produce heat??? Wow!

As for the clutch....... I also had the same problems .... prior conversion to 5 plate but still slipping ...... in my case it ended up being due to the oil I was using in the Primary. Many folk say to use ATF but only with the right letters or numbers, tried it and failed miserably, slipping. After much cleaning I now use a Yamaha motor oil that is approved for wet clutches. Apparently it is down to the "friction modifiers" what ever they are!

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Originally Posted by Dave Martin
Firstly, .... a front brake that generates enough friction to produce heat??? Wow!

As for the clutch....... I also had the same problems .... prior conversion to 5 plate but still slipping ...... in my case it ended up being due to the oil I was using in the Primary. Many folk say to use ATF but only with the right letters or numbers, tried it and failed miserably, slipping. After much cleaning I now use a Yamaha motor oil that is approved for wet clutches. Apparently it is down to the "friction modifiers" what ever they are!

I always say running in oil, its very good as a primary chain oil and not a thin as ATF


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The front brake has good stopping power, but i did fit the 8" TLS off a 69/70 Bonneville or Lightning so maybe that isn’t that surprising that it works well on a B44.

This ride was on ATF as my Dad has had good results in his Commando’s with it, but it didn't work very well at all, I have some fully synthetic 10w-40 that I use for my "modern" Suzuki I will try that as that is approved for wet clutches. Hopefully that with the new plates will do the trick.

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Originally Posted by SamAdamson
The front brake has good stopping power, but i did fit the 8" TLS off a 69/70 Bonneville or Lightning so maybe that isn’t that surprising that it works well on a B44.

This ride was on ATF as my Dad has had good results in his commando’s with it, but it didn't work very well at all, I have some fully synthetic 10w-40 that I use for my "modern" Suzuki I will try that as that is approved for wet clutches. Hopefully that with the new plates will do the trick.

Dont put anything synthetic near a clutch eek least not on these old brit bikes.


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Here are my thoughts on the various issues raised in this post:-
- I don't think there's a huge difference between the AMAL and Wassel carbs, as they are built to exactly the same design, so either will probably work fine.
- as for chokes, I'm not a fan of the design as used by AMAL & Wassel as it seems like a crude way to enrich the mixture. On my A65 which has twin AMAL 930's I have no choke and just tickle the carb which is almost always more than enough to get it started after a kick or two. My B44 uses a Kehin PWK 28 with a separate choke circuit and my Commando uses a Mikuni VM 34 also with a separate choke circuit. Both start well using the dedicated choke.
- for transmission oil, I would stick to something from the same era, e.g. mineral classic car oil 20w50, if you want to use ATF it has to be type F which is an old spec from the late 60's and low in friction modifiers.
- consider doing the 5 plate clutch conversion as mentioned in the Rupert Ratio manual and use Surflex plates which are grippier. You will probably need to lockwire the spring bolts as they have a habit of working loose and lead to slipping.
- My B44 has a SLS 8" brake which works really well, I had the drum skimmed and new linings arced to match the drums, also used a teflon lined brake cable and a handlebar lever with a 7/8" perch (distance between pivot and nipple). The brake is almost as good as a single disc which is remarkable and shows that these brakes can be made to work with attention to detail.


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Allan Why? If the oil is designed for use with wet clutches why should using a synthetic base oil make any difference over a mineral oil?

Gunner, I think you are probably right RE the relative quality of wassel vs AMAL

I have found that the B44 doesn’t need choke with a generous tickle, but on my dads commandoes they will not start when cold without choke.

BSA recommended a 10W30 oil in the primary, Personally I am a fan of modern lubricants where possible and with almost all modern bike oils being designed for wet clutches I think one of these should do well in the application as despite the friction modifiers they should still provide better lubrication for the chain than a mineral oil lubricant without friction modifiers

the surflex plates are on the way and the conversion has already been done, and the springs are drilled for wire so that will be fitted too

my issue with the TLS brake wasn’t performance just cooling and fade, I’ve never ridden a standard single disc brit bike, but commandoes with big discs and 13mm master cylinder and they stop significantly better than my b44 with the 8” TLS, especially when fitted with a BMW R1200rt 4 pot calliper the issue there is front suspension rather than brake

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" Personally I am a fan of modern lubricants where possible" I think the critical part of this statement is "where possible".

Our motors were designed in a different era with very different oils and in particular the very different type and level of filtration required.
Our bikes are often accused of not having any oil filtration, not true, we have the gauzes that take out the big chunks and the sludge trap that takes our the fine stuff. unfortunately the sludge trap requires an engine strip down to clean!
This was no problem as the old mineral oil held most sludges in "solution". Again no problem when your motor had machining tolerances of "T'nearest 'alf inch". Modern engines, not so much. The oil needs to perform to higher levels so has to shed all it's contaminants, which then needs to be filtered.
I use mineral oil but then have external filters on my B44s, as even this oil is not what the motors were designed for, but it seems a fair compromise.

These are just my views, and distillation of various articles read, don't ever mistake me for someone who actually knows what they are talking about!

As far as clutch plates ....... I found that with the "conversion" done I could cram in 6 of the Surflex plates into the basket .... never had a problem

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I don't want to get into the weeds with oil discussions I know enough to know that if you ask 10 people about oil you're likely to get 12 opinions, that being said, the advantage we have with our motorcycles is that thanks to Harley Davidson there are modern oils designed to work with 40's/50's technology.

I also intend to fit a Commando style filter on the return side and a magnetic drain plug to keep the oil as clean as possible, and with how late it's being fitted this riding season I will effectively flush the system with modern high detergent oil to remove the sludge with the end of this year ready for a fresh filter and oil at the start of next year.

I don't think I have room for 6 plates in at the moment I am looking for a OIF B25 primary cover as I believe these are slightly deeper this might give me enough room for an extra plate

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Quote
I don't want to get into the weeds with oil discussions

Completely agree and for what its worth, I think any motorcycle oil will work in the primary as long as it has the JASO MA spec which is wet-clutch compatible.

The other consideration is whether the engine breathing has been converted to B50 style whereby two 3/8 holes are drilled into the left-hand crankcase so that the engine breathes into the primary.

I've done this conversion on my B44 which means the engine and primary oil are shared, this makes the oil blacken quickly with clutch material. This might be an issue if you are running in a new engine with the old-style cast iron rings which need a coarse hone in the barrel and the use of basic mineral oil to help bedding in. I once tried running in a B40 with synthetic oil and it didn't work well, the engine smoked like crazy and the rings wouldn't bed in. If you are using modern rings with a 3-piece oil control ring then I don't think a synthetic motorcycle would be a problem.

Instead of the Norton type oil filter which is quite big for a BSA unit single, I used a Magnefine inline transmission filter which combines a strong magnet and paper element filter to keep the oil clean. It was much easier to hide this filter under the seat than the Norton type, unfortunately they only seem to be available in the US see This Link


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Absolutely agree on the weeds of the oil topic, and also agree that just about any oil for wet clutches will work, lets face it, it isn't doing much in there, I was just justifying the route I took to get to Yamalube 20/50 MA for both motor and primary and fitting a filter.

As far as filters ...... check the MAP universal ones .. I got mine from https://www.bsaunitsingles.com/item.wws?sku=MAP6510.

They are neat and they are in keeping with the looks of the bike.

They can be improved by putting a rt angle on the end tapping and rotating the side one through 90degrees. Makes the routing of the pipes perfect for fitting the unit horizontally under the carb on the battery shelf. It does mean a little bronzing / brazing / welding. Fine if you have the kit and skill, I wouldn't bother if you haven't.

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+1 on the MAP universal filter, they use a Trident/Rocket 3 element and can be easily hidden behind a frame tube.


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Absolutely Fully synthetic isn't good oil for running in new engines, I believe moto guzzi had an issue several years back where they specced fully synthetic oil from new and the fully synthetic oil didn't allow the engine to wear enough to run in, this made them burn oil which led to low oil running which damaged the engines. When i finish my A65T i will run the first 500-1000 miles on mineral/semi synthetic oils before switching to a fully sythetic.

It currently doesn't have the B50 breathing conversion done, Its something i will look into when the engine needs a rebuild but for now everything seems fine so i will leave it until after my A65 if finished.

With the oil filter one of the reasons for fitting it is the increase in oil capacity and hopefully some cooling effect, I'm not particulalry bothered about it being hidden away.

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Just an update on the clutch issue, yesterday i fitted the surflex clutch plates and was suffering with significantly more slip than before i had fitted them (only testing slip on the kickstart), Long story short i eventually realised that the clutch pack was thinner with the new plain and friction plates and this was causing the spring cups to bottom out in the clutch centre i refitted the flattest of the original plane plates to increase the thickness and the slip improved greatly i can still slip the clutch using the kickstart against compression but only if i kick very aggressively I hope to test the bike tomorrow to see what the improvement is like when riding the bike.

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If the clutch is slipping whilst applying pressure to the kick start, it hasn't a snowball in hell chance when you open the throttle and ask it to propel the bike forward


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Originally Posted by Andy Higham
If the clutch is slipping whilst applying pressure to the kick start, it hasn't a snowball in hell chance when you open the throttle and ask it to propel the bike forward

Andy……I’m going to “sort of disagree”. I set up my unit single clutches light enough where you can’t normally kick it through compression. I do it so I end up with the lightest clutch pull at the lever I can get.

There’s no way a B44 with good compression should be started against compression anyway……there’s that starting drill.

I have a hill in my neighborhood that I test my clutch adjustments on. If it’ll make it up that hill in third gear……I’m good.

Can’t say that works for any other motorcycle but it works for my BSA unit singles. (and that’s what the OP is working on)

Gordon

Last edited by Gordon Gray; 08/10/22 10:54 am.

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I’ve seen big single clutches that would slip if you stood on the kickstart, yet worked well on the road.


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I was informed from the shop that i bought the clutch springs from that some slip on the clutch from the kickstart is possible with the engine being unable to slip the clutch under acceleration.

Some "fag packet" maths seems to back this up, If you assume the engine generates around 28ftlbs of torque at peak, with a 3.5;1 primary ratio you would expect a maximum of 98ftlbs torque to be applied to the clutch from the engine, I'm less sure on kickstart ratio's but i believe the it is 2.25;1 which means to get 98ftlbs of torque on the clutch you would need to apply around 43.5ftlbs on the kick start lever or with a 7" lever a downwards force of around 75lbs on the kick start spring, This is around 1/4 of my weight so i think its very reasonable to assume that i can apply more torque on the clutch with the kickstart than the engine can.

obviously i could have the ratios wrong and there are other factors to consider to get an accurate number but i still think that it will be possible toapply more force to a clutch with the kickstart than with the engine.

I will of course update when i have done a road test (hopefully tomorrow) to update on if the clutch still slips

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Sam, be aware there are different springs and cups for those bikes. Long springs in short cups…..or short springs in long cups can cause some grief.

Gordon


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Originally Posted by SamAdamson
I was informed from the shop that i bought the clutch springs from that some slip on the clutch from the kickstart is possible with the engine being unable to slip the clutch under acceleration.

Some "fag packet" maths seems to back this up, If you assume the engine generates around 28ftlbs of torque at peak, with a 3.5;1 primary ratio you would expect a maximum of 98ftlbs torque to be applied to the clutch from the engine, I'm less sure on kickstart ratio's but i believe the it is 2.25;1 which means to get 98ftlbs of torque on the clutch you would need to apply around 43.5ftlbs on the kick start lever or with a 7" lever a downwards force of around 75lbs on the kick start spring, This is around 1/4 of my weight so i think its very reasonable to assume that i can apply more torque on the clutch with the kickstart than the engine can.

obviously i could have the ratios wrong and there are other factors to consider to get an accurate number but i still think that it will be possible toapply more force to a clutch with the kickstart than with the engine.

I will of course update when i have done a road test (hopefully tomorrow) to update on if the clutch still slips

You've gone the wrong way with your maths. With the figures you supplied to get 98 ft/lb on the clutch you will need to apply 220lb to the kickstart


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Yes i realised when i had a little bit more time to think that the numbers probably aren't correct, i'm not sure the ratio for the kickstart is close anyway so i think that was a waste of time, This can be an issue with ball park figures.

But i can confirm that the clutch holds fine even at high throttle openings in high gears up hills, even with some slight slip on the kickstart so i'm happy with the current set up

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