Hitchcocks Forum

Despite many happy reports on the German enfield forum about the pwk-clone, i cannot get mine adjusted right.

Is there info about a 28 (or 30?) mm dell'Orto carb on a 500 bullet 4-speed? Or something entirely different?

The Keihin clone CAN be made to work fine on a Bullet, the former US importer sold a successful kit. This might also be of interest, it's list of PWK settings for a number of different British bikes, including some 500 singles:

http://www.brillbikeparts.co.uk/images/jets.gif

The classic carburettor for a Bullet would be the Amal Monobloc, if you go for a Mk1 Amal concentric, get the Premier version, or go for a Mk2 Amal concentric - all available from our hosts.

I've used Dell'Orto PHFs on Bullets and they're fine, my old Electra-X had a PHF32 (I still have that carb) and my more recent stuff is running happily on PHF36s. There is a PHF30 option still, I think. All the PHF carbs have accelerator pumps, but if you want a non-accelerator pump carb there's the PHBE30, or the smaller body PHBH28 and 30. When RE India first brought out the 350 lean-burn engines for the Indian home market, these came fitted with Dell'Orto PHBH28s.

A good range is here, though you might also have a supplier in the Netherlands, I know there's a French supplier if you're reluctant to order from the UK.

https://www.dellorto.co.uk/product-cate ... 6-to-30mm/

https://www.dellorto.co.uk/product-cate ... 0-to-38mm/

https://www.dellorto.co.uk/product-cate ... 0-to-36mm/

Another point worth noting is that Malossi make a one-piece rubber mounting flange for the Dell'Orto PHF and PHBE range with the correct 58mm centres between the stud mounting holes, so one of these would let you fit one of these carbs straight onto your cylinder head (though you might have to open out the mounting holes for the Bullet's 5/16" or M8 studs, an easy job), their part number is 02 1135.

The other option is of course the Mikuni VM, our hosts still list the 32mm Mikuni conversion for pre-2009 Bullets. Our American friends have also had good results with the flat slide TM32 Mikuni.

I hope this is some help to you.

A.

Thanks, but is 32 not too big?

I like the jrc stuff but quite expensive to get it over here. and.. will they REALLY work out okay?? From the USA it is 119 dollar plus 43 dollar post..

My polini behaves really like a 2 stroke carb. An other needle won't fix it. In a carb there's more difference between 2- and 4 stroke besides the needle.. All the German blokes ride with a 48/125 jet setting. The polini chokes on it, i came to 30/105 at closest, and still running too rich in low and mid-range section.

If.. someone here has a 'secure'tip; You need THAT pwk clone i would be persistent (or stupid) enough to give it another go.

So if there -really- are folks with a kind of pwk on an enfield, there mus be a -big- difference between the makes?

Thanks, but is 32 not too big?

No.

As I said, I have 500 Bullets running happily with 36mm carbs. You can always do a little minor porting work on the inlet if needed, and as I have already pointed out Dell'Oro make 28 and 30mm carbs without accelerator pumps and a 30mm carb with an accelerator pump if you really don't want to go beyond 30mm.

As for the PWK, you can ask on the USA forum, as that's where most of the RE PWK conversions were sold. Is the Pollini the same as the other flat-slide slide Keihin copies?

https://forum.classicmotorworks.com/

A.

The link above (brillbikes) is a reworked pwk body, may things altered.
From origine the keihin pwk is a 2 stroke carb. Despite that many folks seem happy with - an other version- of a pwk, my polini pwk (top of the line of the imitations) really behaves like a 2 stroke carb. Just an other needle won't fix it.

So, there must be s big difference between them?

\Try it again with a cheaper version where is described 'also for 4 stroke? Or be more eh, normal and check out (cannot find revieuws) the dellorto Jochen Sommer sells for the bullets?

One of the attractions of the PWK clones is that they're ludicrously cheap. Some are advertised for universal application, i.e 4 stroke as well as 2 stroke, and the JRC/Brill conversion appears to have been successful. You can buy a selection of different main and pilot jets for beer money, though different needles and slides seem harder to find, you might have to look for Keihin originals.

It looks like Jochen Sommer has taken over production of the Fritz Egli tuning kits for the 624 Super Bullet conversion, the specification for those includes the Dell'Orto PHF34. Some of the Egli Super Bullets were fitted with monster Keihin FCR racing carbs, fancy one of those? Even the Chinese copies sell for about £150!



http://www.motorrad-fuchs.com/en/single ... pment.html

That carb is not too big to work on a tuned 500 with some cylinder head work, a decent piston and cams to suit. Bullet Whisperer over here has fitted Mk2 Amal Concentrics of the same size to some of his tuned Bullets, and they run just fine. But if you think that 34mm is too big, the PHFs are available as 30 and 32mm carbs.

If you're really not happy with what you have, go for the Dell'Orto, OR a Mikuni, OR a Mk2 Amal concentric, and keep the Pollini as a paper weight while your Bullet flies along with a grown-up carburettor!

A.

I’m just finishing Gupta, having fitted a Super Meteor piston and retarding the inlet cam by one tooth.
He’s fitted with a monobloc. I do have a concentric Mk1 which came from a forum member. I might try this after I’ve tried with the existing monobloc; mine is a 350 though.

German report also problems with the (sommer) Dellorto phbh, and are happy with pwk some with blocked powerjet..

There are needels sold for '4 stroke use 'and one site mentiones the JJH needle, but cannot find anywhere THIS needle will solve the problems..
Can try it though..

But, this is a very low tuned single 4 stroke, how hard van it be to give it a good carb??

how hard van it be to give it a good carb??

I think you're making heavy weather of the whole issue, so let's summarize.

There are PLENTY of viable carb options.

1. The Mikarb VM28, if it's in good physical condition, can be tuned successfully for normal riding, Hitchcocks' tuning guide is here.

https://accessories.hitchcocksmotorcycl ... ttor-parts.

2. The PWK clone can also be tuned successfully for normal riding, the JRC Engineering set-up for the 500, as used by our American friends is this, as I posted for you on the US forum.

Carburetor size: 30mm, Pilot Jet: 35, Main Jet: 138, Needle: Standard, Needle Position: Center

But what I wonder is whether the Polini is the same internally as the OKO or other PWK copies.

3. The Dell'Orto is a well established make with a long and successful record on touring and competition bikes. I can't believe Jochen Sommer, who is a respected RE specialist in petrol as well as diesel Bullets, would sell them if they were junk or hard to live with.. Tuning guides are easily obtainable, so are the spares. I don't think I'm the only one here who uses them, either.

4. Both here and on the US forum it has also been explained to you that Amal and Mikuni carbs are also good options, (remember the Bullet was originally designed to run on an Amal) many satisfied Bullet owners are blatting around on their bikes with these carbs fitted, you don't seem to have acknowledged this.

A.

Yes, maybe the polini pwk IS diffrent? f i try the jetting 'they all' use, it chokes..
48/125 vs my 30/105.

And yes, rthere are pwk-clones offered on ebay as 2 and 4 stroke, BUT equipped with a powerjet..
and powerjet (which you can disable) is solely for 4 stroke?

So, i do not know WHICH pwk i should get.. expensive doesn't work... 20 euro's is maybe too cheap to get something working?
The OKO is reperted to be better (different neelde) then koso burt cannot find..

Also i can not find if the pwk needles (= JJH or not??) is enought to make f.i. my polini fit for 4 stroke?

I have a set of needles but which too use?
And this way i can keep myself awakat night and tired during the day..