gii Posted December 28, 2013 Report Share Posted December 28, 2013 Still working on my 'new' 500 long stroke Ariel The carb is an Amal concentric 626 and it's worn. Specifically the slide is very worn with loads of movement in the bore but a new slide is very tight which suggests a poor / distorted body. The jetting is bushed pilot, 106 needle jet, 160 main jet, 3.5 slide. Now I could order a new carb with the same jetting but I think people are using 622 carbs these days to improve low speed running and control. If that is the case would I keep the same jetting and slide in the smaller carb or would I have to change it? Quote Link to comment Share on other sites More sharing options...
laird387 Posted December 29, 2013 Report Share Posted December 29, 2013 Hi, One of the 'old' tweaks with all Amal carburettors, was a simple mod that vastly improved power pick-up from trickling along on tickover. The ruse was to take out the needle, then block the little hole near the to with a blob of solder. It came from the AJS competition shop, through Reg May at Comerfords. I used it on all my AMC and Ariel triallers and found it a great improvement. In any case, if it didn't work, you could always get out the soldering iron and remove the blob. Enjoy 1 Quote Link to comment Share on other sites More sharing options...
woody Posted December 29, 2013 Report Share Posted December 29, 2013 I'm lost with this one ?? What hole, where? Needle or needle jet? The needle doesn't have a hole in it. The 4 stroke needle jet has two holes at the top, the 2 stroke needle jet doesn't have any. Quote Link to comment Share on other sites More sharing options...
laird387 Posted December 29, 2013 Report Share Posted December 29, 2013 Hi, Sorry about that, the hole was in the needle jet - and I had forgotten that very few current riders use the old carbs... Ne'er mind - I'll dose off in my rocking chair again. Quote Link to comment Share on other sites More sharing options...
woody Posted December 29, 2013 Report Share Posted December 29, 2013 Still working on my 'new' 500 long stroke Ariel The carb is an Amal concentric 626 and it's worn. Specifically the slide is very worn with loads of movement in the bore but a new slide is very tight which suggests a poor / distorted body. The jetting is bushed pilot, 106 needle jet, 160 main jet, 3.5 slide. Now I could order a new carb with the same jetting but I think people are using 622 carbs these days to improve low speed running and control. If that is the case would I keep the same jetting and slide in the smaller carb or would I have to change it? Can't advise on the best option of 22 or 26mm for an Ariel, but if you're buying a new carb I'd consider the new Premier version with the pilot jet in the side. I've fitted a 22mm Premier to my BSA which is a long stroke C15 (337cc) and it's an improvement over the normal concentric. Much much smoother and predictable off tickover and seems stronger through mid range to top end. Main jet is 130 and needle is either 105 or 106, can't remember which. Pilot is a 17 (new numbering convention for these as they are completely different from the normal pilot jets) Quote Link to comment Share on other sites More sharing options...
woody Posted December 29, 2013 Report Share Posted December 29, 2013 Hi, Sorry about that, the hole was in the needle jet - and I had forgotten that very few current riders use the old carbs... Ne'er mind - I'll dose off in my rocking chair again. ok, understand that thanks. You could just try a 2 stroke jet then as they are the same but without the holes, saves the soldering. Quote Link to comment Share on other sites More sharing options...
trickymicky Posted December 29, 2013 Report Share Posted December 29, 2013 ok, understand that thanks. You could just try a 2 stroke jet then as they are the same but without the holes, saves the soldering. The mod referred to applied to the Monobloc. It involved blocking the bleed holes in the needle jet. It helps the engine to pick up cleanly at the end of a long or steep descent. Ariel HT's and genuine AMC Trials bikes had this done as standard, and this is why the original carb of, say, the HT, a Monobloc 375/64T, has the T suffix. The T means no bleed holes. Quote Link to comment Share on other sites More sharing options...
woody Posted December 29, 2013 Report Share Posted December 29, 2013 Thanks Mick, I did wonder initially if it was referring to monoblocs but as we were talking concentrics I assumed concentrics in the end. Can this trick be used on concentrics? I don't know what those bleed holes actually do. Someone did explain once but I've forgotten. As usual... Quote Link to comment Share on other sites More sharing options...
trickymicky Posted December 29, 2013 Report Share Posted December 29, 2013 (edited) I dont think its a problem on the concentric Dave, so i've not heard of anyone trying it. Dont try a 2 stroke jet on a four stroke though, as they are different other than the lack of bleed holes. Have you seen the new aluminium concentric? They do it in a 20mm too. Edited December 29, 2013 by trickymicky Quote Link to comment Share on other sites More sharing options...
woody Posted December 29, 2013 Report Share Posted December 29, 2013 I dont think its a problem on the concentric Dave, so i've not heard of anyone trying it. Dont try a 2 stroke jet on a four stroke though, as they are different other than the lack of bleed holes. Have you seen the new aluminium concentric? They do it in a 20mm too. ok, didn't realise they were different. New concentric - do you mean the Premier with side fixing pilot jet? I've got one on the BSA and the low down response is much better than the standard concentric I had before. It no longer has an erratic or unpredictable pick up off idle. Now pulls cleanly and smoothly from idle every time. Quote Link to comment Share on other sites More sharing options...
trickymicky Posted December 29, 2013 Report Share Posted December 29, 2013 No, they do a range in Aluminium rather than mazak and include a 20mm one, which is smaller than the previous smallest of 22mm. They are of the premier design. 12 ounces lighter apparently, but it would be nice if they didnt wear as quick. Quote Link to comment Share on other sites More sharing options...
woody Posted December 29, 2013 Report Share Posted December 29, 2013 ok, I see, my knowledge of materials etc is pretty limited so not sure what the one I have is made from. Didn't realise they made them from two different materials, so I'm guessing mine isn't aluminium. They never mentioned materials when I tried to buy mine. Three times I've tried to buy a carburettor direct from Amal and three times they've told me I'd have to wait about 5 to 6 weeks as they didn't have any built up and the next production run wasn't due for another few weeks. I bought it from Surrey Cycles in the end, delivered next day. Quote Link to comment Share on other sites More sharing options...
charlie prescott Posted December 30, 2013 Report Share Posted December 30, 2013 Hi Guys. Thanks Mick? Did not know they now did the 20mm size, And was about to buy a new carb from Berlems. Dave your information is even more revalent for jetting , I should have asked you in the first place. Thanks guys nice one, and a Happy New Year to both of you. Regards Charlie. Quote Link to comment Share on other sites More sharing options...
laird387 Posted January 1, 2014 Report Share Posted January 1, 2014 Hi, Happy New Year to all Ariel afficianados - and a special 'Hello' to an old friend of mine, whose picture did appear in my offroadarchive from time to time ! Who - why Trickymicky, of course. Enjoy Quote Link to comment Share on other sites More sharing options...
jon v8 Posted January 3, 2014 Report Share Posted January 3, 2014 I found the spec sheet for the carb Surrey Cycles sold me 3 years ago fo my longstroke HT. Mk1 Concentric - 626/300 #3 Brass slide 200 main jet 106 Needle jet 30 Pilot jet - Bush removed. More than happy with this setup,all I've changed is the throttle stop screw,its now one from Wayne - Billet parts UK,with a knurled end so you can adjust idle speed even with gloves on.The engine starts and runs well,does not foul plugs and will pick up from right down to virtually zero revs. Quote Link to comment Share on other sites More sharing options...
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