Unofficial Royal Enfield Community Forum
Royal Enfield Motorcycles => Bullet Iron Barrel => Topic started by: winsun-enfield on April 02, 2021, 08:35:00 am
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Hello internet,
Besides my enfield with winsun diesel i overhauled a '94 500 bullet.
The carb which came with it was utter crap so i decided to get a pwk-clone. May folks on the German enfield forum get one cheap (40-50 euro's) and seem happy with it.
Okay, cool.. There are some reports about quality issues with the cheaper ones (logic i think) so i got the most expensive of the cloneb i could find; a 28mm Polini PWK.
Alas, after many efforts, i can not get it adjusted right, it really behaves like a 2 stroke carb and -only- an other needle won't fix that.(there's more difference in a carb in this)
so, i made a bet on the wrong horse..
Now i could trt a pwk clone again(but which to be sure it works out?)
Besides that, a German dealer offers Dellorto PHBH30mm for the bullet 500.
Is there any expereince here with those?
Further i would be interested in setting/which intestines a -japanese- and which type mikuni should have.
At last i would like to know how the JRC carbs are getting along..
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I dont understand that. Carbs should be easy to install and adjust. And run great ever after without fault.
Enough of pro Carb propaganda.
Withstand the temptation to use a racing carb with too much diameter. They will give you more hp on full throttle but they are not drivable in lower rpm.
Dellortos are prone to not beeing consistently adjustable. Mikuni are great carbs. Use an O2 sensor to adjust your carb through all rpm. Everything else is just guesswork.
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A 2 stroke carb differs in more things then just the needle, the polini pwk is apparantly solely a 2 stroke carb. Some other pwk clones apparantly are 'universal'?
Are there people here who have tried JRC carbs? These are 'made from'pwk's, Íve read some complaints about the glued on flange that loosens, restrictive fuel intake and sticking slides..
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Mine came with a PWK on it already. I believe these were sold by Classic Motorworks when they were the importer. No idea what model it is but I can tell you it works flawlessly.
You could always stick an Amal on it. Plenty of knowledge out there on those and it would be 'original' to what these came with back in the day.
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My PWK 30 with a glued on flange has operated perfectly for the last 15 years. As an aside, what is the difference between a 2 stoke carb and a 4 stroke carb that you guys speak of?
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@ ddavidv and cyrusb
So what jets/needle settings are on your PWK?
@ viczena,
Withstand the temptation to use a racing carb with too much diameter. They will give you more hp on full throttle but they are not drivable in lower rpm.
Here's Bullet Whisperer on a 500 Fury fitted with a 38mm Amal Mk2 on a mix of country lanes and main road, it looks pretty drivable to me!
https://www.youtube.com/watch?v=p-Q11n9D4A8
@winsun-enfield
40 to 50 Euros? THAT much???
https://www.ebay.co.uk/itm/30mm-Universal-Motorcycle-30-PWK-30mm-Carburetor-For-Keihin-OKO-Fit-Race-Scoo-BE/174368669640?hash=item28992ebfc8:g:KWcAAOSwdMhefPrE
A.
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Exact size I don't remember (15 years is a long time), but I do remember it came with 2 extra jets 1 larger and 1 smaller than the one installed. After trying all three it ran perfect with the middle as shipped jets. And of course thats with cone filter and free flowing bottle exhaust.
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Most, if not all, of these fake PWK carbs are from OKO in Taiwan. They used to be on Ebay for around 20 bucks or so.
The problem with these carbs, besides being so cheap that people can sell them and make profit at $20, is that it is very hard to get proper jets and needles for them.
JRC uses a OKO and glues a manifold stub on it.
Why don't you do yourself a favor and buy a real carburetor?
A VM32 Mikuni is only about $100, and a manifold from Sudco is about $25. All parts are readily available, and so are tuning instructions.
If you stick to the cheap stuff, you will never get out of your vicious circle of poor carbs.
My 2 cents.
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I would like a good mikuni,. but what slide, neelde, jetting?
An enfield dealer sells dellorto phbh's for an enfield.. also revieuws about hard to adjust.
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I would like a good mikuni,. but what slide, neelde, jetting?
An enfield dealer sells dellorto phbh's for an enfield.. also revieuws about hard to adjust.
There are many example of Mikuni jetting and tuning for VM32 or TM32 on this forum in the archives. Use the search function.
It is likely that you could get it very close to correct on your first try, if you read what others have done.
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ACE @ # 7: a hearty +1 to not buying more cheap unsupported crap.
Get the pre-sorted Mikuni or the Amal, or simply make the MikCarb work with Hitchcocks jetting chart. Carbs are just so stories, once dialed they work well. You can pull a lot of hair out becoming a carb tuner, or you can get the sorted model and enjoy riding the bike. Fine tuning is one thing, starting from scratch is another.
Two-strokes are completely different engines, the intake mix gets gargled through the carb more than a 4-stroke does. The needle jets are different for one thing, often they hade "shields" on them. Without ready access to a box of tuning bits specific to your exact carb, there's a lot of guesswork involved. IF you can find another fellow that has a 28mm PWK on a Bullet AND has tuned it to run well AND has recorded in detail the exact internal bits used, you yourself can spend a large block of time rediscovering the wheel.
A new OEM MikCarb is about $100, the tuning path is well trodden, parts are readily available from H's to compensate for intake & exhaust mods. Both of mine work well. Unless you are running a forged piston, steel rod & needle bearing con rod and routinely winding to 6,000 RPM striving for HP, the 28mm MikCarb is good enough. For about $200 you can get the Amal, already sorted, well supported, with maybe a better choke system. The Mikuni is the same story but with better parts. I'd sort the MikCarb and go riding.
https://accessories.hitchcocksmotorcycles.com/accessory-shop/carburettor-kits/38529
PART No. 90086 ; CARBURETTOR KIT, MIKUNI 32mm (1989 - 2007 500 Bullet) ; £249.00
This is a genuine Japanese made 32mm Mikuni carburettor with all the necessary parts to fit the 500cc Bullet. It will give improved performance over the standard carburettor. The kit comprises of a Mikuni carburettor, special manifold, S&B air filter throttle cable and spare jets etc.
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Is it painted blue?
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I was wary of the Chinese-made copy of a Taiwanese copy of a Keihin, so I went with JRC's Taiwanese copy. They offered me the jets to tune it but I got them on eBay from one of many suppliers. My bike ran fine after fettling with a main change and needle adjustment. The JRC bolts right on and negates the need for a leak-prone rubber hose.
I would avoid any PWK sold for $20.
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@ #11: It worked again!! ;D "Like a tuna to the bait..." Roy Latimer, 1986
@ #12: Stanley - Do you have the JRC Carb & jet numbers you used? It'd save a lot of trial & error. I like the bolt-on approach also. Any links to share?
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I'm afraid my notebook went to the new owner, but JRC was helpful with jetting.
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Oh well...we can always dig around here I suppose - https://jrcengineering.com/technical-support/jrc-pwk-carb-instructions/
Was that the "Boss Hoss Blue" or the "RT1200 Uber Alles Blau" you used? Stands out well from they grey background!
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I just dont know what you are talking about. Maybe the blue colour dizzes your mind?
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@ #16: Did you write the response at #14? If not, I can see the confusion.
These folks can help : https://www.blublocker.com/
Not sure if they'll help with the dizzy spells though. Best to avoid operating motorized equipment until that clears up.
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Yes, #14. "I'm afraid my notebook went to the new owner, but JRC was helpful with jetting."
Therefore you have to wear sunglasses. Or you wear sunglasses? Or want to wear sunglasses? It gets more confusing every time.
Maybe its really the best if you avoid operating motorized equipment until that clears up. Sounds like a good idea.
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@ #14 was written by Stanley. So you're Stanley, not Viczena? This is getting deep! :o
I think what was actually going on @ #14 was that Stanley was poking a bit of good natured fun at me for using blue font. Now we're ostensibly embroiled in a discussion regarding the theoretical effect of blue light on cognition. I have copied in a reference regarding possible effects of blue light, left in black font so as not to trigger an adverse response.
https://www.theraspecs.com/blog/light-sensitivity-and-dizziness/#:~:text=Blue%20light%20is%20the%20most,other%20forms%20of%20artificial%20light.
" Blue light is the most likely to trigger photophobia, migraine attacks, and other symptoms of chronic conditions (including vertigo, dizziness and disequilibrium). Plus, these wavelengths are literally everywhere...in fluorescents, device screens, and other forms of artificial light. "
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BUT in the JRC instructions (when you gentlemen have quite finished), if you scroll down you do indeed come to some settings PWK carb settings for the Indian-built Royal Enfield Bullet. The 350 and the 500 AVL are also included, but THIS is what the original poster is looking for!
Thank you for the link!
A.
Royal Enfield 500 (Iron Barrel)
Carburetor size: 30mm
Pilot Jet: 35
Main Jet: 138
Needle: Standard
Needle Position: Center
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@#19: So now you are triggered by photophobia? Explains a lot. But what has your malade to to with Royal Enfield?
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Ha Ha, Touché, Adrian II! Glad we were of accidental service. Sorry for the misappropriation.
Viczena, continue on: " Denigrating all things Swedish "? It seems appropriate for this level of discourse.
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So what has sweden to do with the topic? You seem more and more confused.
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The only guy confused here is busy burning up bandwidth answering my reply to Stanley's post #14. Are you "winning" yet? Any more phrase inversion "zingers" to get out? This isn't adding value to the Iron Barrel section, it's just spleen venting. The Campfire Talk is a better place for this, "Denigrating all things Swedish" seems about the right box for this level of discourse. No reason to muddy the water here even more.
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You say the carb on it (presumably the Mikcarb) was utter crap, Why? Is it worn out, broken or just not setup right.
If it's just not setup then it is easy to sort.
I had rarely played with carbs before my Enfield and it was shithouse, but I have sorted the Mikcarb with a little help from the brains trust on here. It is now very well behaved, no backfire on the overrun and smooth delivery throughout.
Just a simple change to the pilot & main jets - with a little trial & error.
Geoff.
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My PWK 30 with a glued on flange has operated perfectly for the last 15 years. As an aside, what is the difference between a 2 stoke carb and a 4 stroke carb that you guys speak of?
Can you tell me if your needle has a code on it? (f.i. JJH?) i am wondering if you can 'secretly'convert a 2 stroke pwk to a 4 stroke with only a different needle.
Normally, there's more difference between a 2/4 stroke carb (venuri, atomiser)
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I was wary of the Chinese-made copy of a Taiwanese copy of a Keihin, so I went with JRC's Taiwanese copy. They offered me the jets to tune it but I got them on eBay from one of many suppliers. My bike ran fine after fettling with a main change and needle adjustment. The JRC bolts right on and negates the need for a leak-prone rubber hose.
I would avoid any PWK sold for $20.
But, the JRC's are NOT 20 dollar copies with a flange glued on? Is there more difference??
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My choice of carb was based the observation that every Taiwanese product I've encountered was on par with Japanese products. BMW and Piaggio use tons of Taiwanese components including engines.
The Chinese PWK copies are packaged to resemble the Taiwanese carbs but with small clues that can alert the buyer to the poorly made Chinese cheap copies with generic jetting. The defects of these "$20" carbs are often the fodder of motorcycle fora and blogs.
JRC sells Taiwanese carbs jetted for specific bikes and fits them with a flange that could be called glued on but to my eye is substantially bonded. They also answer emails and sell carbs for a range of Brit bikes.
To me, the PWK was better than the Indian copy of an ancient Japanese carb.
BTW, I would have gone for a classic, simple Amal if they weren't so steep.
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Thanks all for reply.
Browsing on ebay you can see pw clones for 2 stroke and also 'universal'
Strangely enough some of them still/do have a powerjet and even rodder in the venturi?
https://www.ebay.nl/itm/124253110318?mkevt=1&mkpid=0&emsid=e11051.m43.l1123&mkcid=7&ch=osgood&euid=6db8477133c349038c396b6a75cbd8bd&bu=44889393723&osub=-1%7E1&crd=20210404174641&segname=11051&sojTags=ch%3Dch%2Cbu%3Dbu%2Cosub%3Dosub%2Ccrd%3Dcrd%2Csegname%3Dsegname%2Cchnl%3Dmkcid
And, i know that (maybe) te greatest blockage is in my head, but given the 'normal' differences between a 2- and 4 stroke carb (you have -at least- to change the needle, atomizer, jets and slide to convert the one to the other) Ho can one be suitable for both?
I was searching for an OKO 30mm, made in Taiwan, whithout powerjet,for a price you can expect some quality (around 40-50 bucks) but did not succeed yet in such.
Is the -far more expensive- JRC carb nothing more then a cheap OKO with a flange glued on them?
I've had several bikes with amal carbs, besides they seem to wear out fast, they seem very crude and hard to finetune..
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The Amal tuning advice is easy to find on-line.
http://amalcarb.co.uk/downloads/
Amal's wear problems are in the carbs with zinc-alloy slides in zinc-alloy bodies, you can buy brass, chromed brass or hard anodized slides which are much harder wearing. Try a 30mm Mk2 Concentric.
And, i know that (maybe) te greatest blockage is in my head
You have convinced me! ;D
A.
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A shame that import fees/taxes make a JRC almost twice as expensive, as i would surely like to try one.
Plan is for now, get a Taiwan-made OKO pwk 30mm, but insecure if i buy another pwk that only works on a 2 stroke like my polini (which was 90 euro)..
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You are looking at a total spend of $150 Euro total for things that might work.
A stock Mikcarb is about $100 plus any additional jets, the pre-sorted Amal from H's about $200.
For about $50 Euro more than you are thinking of spending/ have spent for things that might work you can get something that does work. Save up coffee money for a month and get a known good part.
There's nothing stopping you from selling the carb you purchased that didn't work for you. It'll defray the total cost, and you can write it off as a "learning experience".
Just buy the part you need that actually works and go riding. The other option just creates misery, and life is way too short to be miserable.
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Having just rebuilt a pair of Monoblocs on my Interceptor, I don't know why there is reluctance to use an Amal. They are absurdly simple carbs. A new one won't suffer the slide/housing wear of the originals which is their biggest flaw as I understand it.
I did have to use some Dowty seals on mine to keep it from leaking but the 'mechanicals' of the Amals are sound, IMO.
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You are looking at a total spend of $150 Euro total for things that might work.
A stock Mikcarb is about $100 plus any additional jets, the pre-sorted Amal from H's about $200.
For about $50 Euro more than you are thinking of spending/ have spent for things that might work you can get something that does work. Save up coffee money for a month and get a known good part.
There's nothing stopping you from selling the carb you purchased that didn't work for you. It'll defray the total cost, and you can write it off as a "learning experience".
Just buy the part you need that actually works and go riding. The other option just creates misery, and life is way too short to be miserable.
Yes selling the other cabrs mighrt raise some money.. but the ruibuild of the bike alreadys costed more then it is worth, and spending 300 euro on a carbb.. well, maybe later.
In meanwhile someone offers to sell me a dellorto phbh which has done service on a bullet 500 for a low price.. I will try it and look further in due time..
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Great. Sell your used carbs that dont work to some simple minded guy on ebay and buy another used carb yourself. That certainly will give you great value for low price.
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It looks like the polini comes with a 45 slow jet and a 114 main . That slow jet may work , but a 35 or 40 may be better, the main should be a 130.also block off the power jet.