MKIIA 850 carb needle: bean can vs peashooter

NortonMKIIA850 said:

Bingo, thanks WZ507!

Click to expand...

Bingo??

You'd already been directed to that information further up the page! :?

L.A.B. said:

NortonMKIIA850 said:

Bingo, thanks WZ507!

Click to expand...

Bingo??

You'd already been directed to that information further up the page! :?

Click to expand...

But sometimes you can't see the forest for the trees, and a needle is a mighty slender tree . The trees had to made fat and colored blue and yellow to make them stand out?

Yes I know! I was just being grateful ... cheerful ... I finally noticed it last night, sorry I didn't mention it earlier L.A.B. but I've been buzzing today – I took the bike out for another blast and it's cracklingly good! Mind you I did find that, using engine braking at fairly high revs in second down a steep, single-track country lane, a bit of popping re-appeared at points where I wanted to open the throttle just a crack, so I'm tempted to move the needles up a notch – as has also been suggested previously. Otherwise I'm a very happy camper right now, as far as the bike goes. Sort of like new, maybe the best it's ever been. Yes indeed about needles and trees! Cheers.

Well – I give Burlen 11/10 for customer service! Having sent them my StayUp floats for inspection as I couldn't get good fuel levels, I was asked also to send them a pair of float bowls that they could set up for me. I got back: 2x brand new StayUp floats c/w aluminium needles and (stainless?) spindles; 2x brand new float bowls c/w 1-way banjos, nylon filters and associated screws and fibre washers, and metal (chromed brass?) drain plugs and fibre washers; 4x drain plug fibre washers (separately); 2x float bowl gaskets; 4x Pozidriv float bowl screws and spring washers. Plus my old float bowls back. Invoice Total 0.00. I'd rate that higher, but it only goes up to 11! :wink: It'll take me a day or three to get around to fitting them, for now I notice that the new spindles, which are possibly ½ a thou thicker than the old ones, sit slightly proud of the new float bowl tops, which the old ones don't, in the old float bowls – that could well prove to be significant; and the needle seats in the new float bowls appear to be at, or virtually at, their lowest setting. I'll post again when they're on, can't wait!

I spent this afternoon blasting to Cosmo's in Hastings and back, still buzzing!

I finally got around to fitting the new float bowls with StayUp floats and aluminium needles today. Pressure of time meant that I didn't do any comparisons before putting them on, sorry. Anyway, fuel levels look to be around the bottom of the specified range. But in this instance the proof of the pudding is in the riding (?!), and the bike's very happy, so I'm very happy. For now, I think if anyone has an experience like mine, and finds themselves getting nowhere, they could do much worse than contact Burlen for a returns number, and go from there. As things stand, their customer service for me has been stellar. What I might have been doing wrong, and what Burlen have done right, I have no idea! But if I don't have to go in there again for a long time I shan't mind. Fingers crossed that things stay as good as they are now.

Also, while working on the carbs, I found that one of the carb/manifold nuts was slightly loose – you might recall I tested for air leaks due to minor popping on the overrun, but didn't find any. So I've taken that carb and manifold right off, cleaned up all the joints and re-assembled: blue LocTite on the carb/manifold studs, the nuts done up just tight enough to compress the O-ring and flatten the spring washers, I hope that meets with general approval. And the popping's gone! So I must've missed an air leak, hey-ho! At least I can leave the throttle needles alone! Pending the results of a plug chop, maybe ... Once warm, the tickover seems pretty steady at around 1,000rpm, which'll do fine for me, but since stopping the air leak I'll want to have another play with that. Cheers.

An update: things remain better than ever, and I've decided not to mess with the 1,000rpm tickover as it's so steady. I never thought I'd be able to write that! Pulling 80mph seems positively easy now, although I've not yet been tempted to go over 90mph – nowhere nearby to do it, too much traffic, unmarked police cars patrolling … So I've no idea what top speed might be. Most interesting of all though, whereas the bike already had 260 main jets instead of the smaller ones specified, and I've now got the richer no. 3 slides instead of the standard no. 3½, fuel consumption has gone from 47–49mpg to 53–55mpg! Maybe after all the money I've spent on the bike this year the Norton god is smiling on me …! Couldn't have done it without all the patient support on this forum though, so thanks all once again!

Good news then, the Premiers are excellent bits of kit for the money, it is suspected that they do run lean for the standard Commando settings. Not surprising as the original 70's AMAL's were most probably worn out when fitted new as they were made on worn out machinery, with the tolerances being achieved these days, no wonder they work better.

Thanks yes, except I don't have Premiers – just refurbished Mk1s! Fitted new by me in 1999. But now with Stay Up floats and anodised slides, besides all new jets (except the pilots of course) and needles. From what you say, maybe Amal parts are more accurately made now than in the '70s (and '90s) ..? If I'm still capable of riding when the present carb bodies wear out, Premiers are probably the way I'll go! Cheers.