Amal 46NE

[whigum]

Hello, two questions Firstly, what is broken off on the carb body, above where it says 46NE? Secondly, I am hoping to pair this carb with a Silver Century block.. but it seems an overly tight fit. I measured with calipers, and the OD of the block's inlet tube is around 0.5mm larger than the ID of the mating on the carb body. Seems fine, as the carb has slots cut out to help it stretch.. but I'd rather not force and snap it - are these parts definitely compatible? The Silver block is the one with the rubber o-ring on the exhaust outlet. I may actually be in the market for a better carb, this one is mostly fine (bar snapped thing?), but there is some corrosion on the inlet etc.. so let me know if you have a better one going

[Nudge]

only thing I can see from the pic is the storm cowl in missing (and the fuel bango / float)
It should fit on a silver but it may have come off a 102.

[whigum]

I removed those parts for cleaning, nothing missing. It's just that circular part above the 46NE mark, looks like a snapped bolt head? On the inside there is a notch which locates the slide. The carb actually came off what I think is a Century 100 block, it had a piece of tube inserted as a bushing to reduce the ID, I think it may have been squashed in a bit from being clamped onto the smaller inlet.

[Hugz]

It should have a hex headed stud there which is the locator for the internal slide. Im assuming somebody tried to remove and snapped the head off. If the slide slides up an down it will probably work as is. I thought the 102 and SC has the same size stub but I'm not up on those new fangled SC's

[whigum]

Thanks Hugz. I was hoping it was just a locator, and not something more. The slide seems fine, so it will do until I find a better one I guess

[headdownarseup]

NOTHING wrong with your carb Whigum.
You have a late model carb that's all.
The earlier versions of the same carb had a removable throttle slide GUIDE.This is what Hugz was trying to describe.
Later models carbs got the slide GUIDE replaced with a rivet. This is what you can see in your carb. Nothing broken, they're supposed to look like that.

Double check your cylinder inlet against the internal bore size of the carb to make sure they're the same dimensions. If not, something's wrong. Any air leaks around the carb inlet will only cause problems later on, so a nice firm fit on the inlet is fairly essential for good running.

In a nutshell, any 46n 2jet carb (old or new) will fit any 102cc block, whether they're a round block like the 102's, or the square block engines like the century's.

The only exception to this is with some variants of the century engines fitted with a villiers carb, but they will have the inlet stub on the opposite side of the block just like the smaller 40 series engines.

Jon

[Keith.P]

You will find it was a bolt and it should have a bolt, one look at the picture tells you that.
Yes it will work fine as is, is it right, NO.
My 40's Anzani super single 158cc motor is fitted with an 46N, but will it work on a 102cc seagull.
So saying any 46n 2jet carb (old or new) will fit any 102cc? Maybe they will fit, but not every 46N was made for a seagull outboard.
Coming out and saying any 46N will work is not true.

[Oyster 49]

Keith and Hugo are quite correct. The screw in location peg that locates the slide is there but the hex head has broken off, so just the threaded pin is left behind.

Those carbs are used all over the place, my early Britannia engines have a 46 with a 2 bolt flange, but they are still a 46!

http://www.ebay.co.uk/itm/SEAGULL-OUTBO ... xyRhBS1pJ9

It does look like the clamping surface has been squeezed inwards by fitting the carb onto a inlet stub designed for a villiers carb. Perhaps you can very carefully open it up a bit to give clearance to fit.

[headdownarseup]

True Keith, not every 46n was fitted to a seagull.

Is there any chance that Wighum's engine might have originally been fitted with a villiers carb before. This might explain why the clamping area of the carb has been slightly crushed and a plastic insert used inside the inlet bore?
Engine serial number would help a bit here!

For what it's worth, my 1978 wspc has EXACTLY the same carb as pictured. Identical in every way. I have 3 others that look the same as well, so definitely not a coincidence. They are supposed to look like that,there's nothing broken just slightly redesigned compared to the older types.
Earlier 46 type carbs (as mentioned) have a removable throttle slide GUIDE which if you look at it appears to be a small hexagonal nut. Later carbs (as above) have been slightly re-designed to look as they do, more like an insert rather than something that's screwed into the main body, but essentially a guide for the throttle slide/piston to travel up and down without rotating inside the body. If you look at the bottom of the slide they have a WEDGE shape to the bottom,which when fully opened will uncover the main jet (the longer of the 2 jets). If this throttle SLIDE was allowed to rotate inside the main body of the carb (much like the villiers carbs) the fueling would be all over the place. Hence a guide for the throttle piston. The throttle piston will have a corresponding groove cut into it,and it's this groove that locates over the guide to prevent any rotation, just up and down, but more importantly keeps the throttle piston in the correct orientation for proper air flow over the jets


I've fitted the same type of later carb onto some much earlier 102's and century's, and guess what, they work too. They work just as well as any other 46 type carb you'd expect to find on these things.Why wouldn't they? Apart from a small change to jet sizes they're basically the same carb with a few very minor external casting differences, but nothing that would prevent the engine from operating normally. I must have seen dozens of 102's and centurys with odd looking carbs over the years. Some much older motors with newer looking carbs, and newer motors with very much older carbs (as described). They all work just fine, just make sure the jets are correct for whichever application you choose to run them on.

As for anything non-seagull, you'd have to ask another expert.

Hope that clears things up

Not trying to burst anyone's bubble over this, but i have spent a lot of time in the past experimenting with many different things. Carbs was just 1 of many things i've played with on seagulls


Jon

[Keith.P]

All I'm trying to say is, most of us know about carbs, but most people that come on the site asking questions don't know the first thing about seagulls, that's why they are asking.
So it needs to be the right answer, not any 46n will do. It stops questions a week later saying "it doesn't run right".

Like today, I saw a post, "I need a new sparkplug", DO I LEAVE THE SPACER ON THE MOTOR.
NO, the old plug is a two piece Lodge spark plug and half of it is still fitted to your motor.

[whigum]

As usual, the thread has turned into some interesting reading and good information. Thanks guys

I am going to agree on the "broken thing" being insert type affair, rather than a snapped bolt. What made me unsure initially was a combination of seeing photos of other carbs with a hex head there, and that the inner part did not look like the end of a bolt coming through. Great, so the carb isn't too bad

As far as the carb not fitting, I got it on now. I was right about it being squished in half a mil or so.. it has four cutouts around the rim, they had been compressed because this carb came off a block with a Villiers/smaller stub. It had been bushed down to fit, and clamped very tightly. Some persuasive taps with a rubber mallet got it on.. it now goes on and off freely yet snugly as it should.. guess I bent it back to shape. This carb is going on my first Seagull rebuild/restore, so I'm pleased to have everything worked out now!

[Keith.P]

It was most probably bent out of shape, if it had come off a 100 model, as that model has a smaller size stub for a Villiers carb, so you can understand why the Amal carb has that damage.