Jets for PWK carb

Hi,
I was thinking i'd get a 24mm PWK style carb for my SP180 to replace the original dellorto. Bike is standard at the moment including airbox and exhaust. Am going to try my best to hook it up to the airbox and looking at a motoforce 360 intake set.

Could someone please tell me an approx range of main and slow jets i would need to tune it. They come in different size ranges.

The carb comes with 110 main jet and 40 pilot.

Thanks,

 

i would say main would be 180+ my 70cc was on a 142

 

Anyone with experience on a 172?

I understand that no one can tell me exactly what I would require, it's just that the kits seem to vary alot in size. Packs of 10 main jets are available for sizes 100-122, 125-148, 150-172, 180-205. I was hoping to get a ball park idea.

 

Have you already bought it? If not get a 25mm delly IMO.. Work very well performance wise and easy to jet (100-122 box and work down)

 

Haven't bought it yet. Am tossing up between the two. Had just heard that the PWK style has slightly better mid range performance. Does seem difficult to find info on setting them up though.

 

I think thats the sales pitch..theres good and bad for both really but its preference more than anything IMO. With some PWKs though youre buying new needles and pilots among other stuff so of course it runs better whereas nearly every 25mm ive come across is already close enough and has only really needed main jetting..Even my 28mm on my 70 i only really need to do the main, havent even touched the needle or anything

You can probably get either running as well as the other but thats obviously dependent on how well you know the carb and if your coming from a stock delly its basically a bigger version of the standard one which is handy

 

You got a good point there. Had a few problems with the std delly but there if definitely more info on the 25mm one out there than the PWK type and i'm not an expert on tuning by any means. If there is little difference in performance then I think i'll go with the 25mm delly. Thanks.

 

Think I had around 110 main in my 25mm on a 172 with a filter..and whatever pilot it came with. They are quite good imo they work the best on these size engines out of all the carbs ive tried

 

I was going to try to keep the std airbox and I think there is an inlet that allows this. Also standard exhaust. Should be similar main jet or one down maybe?

 

25mm dell is the easy way, flat slide is the power option.

there is massive difference in performance in the two carb types. PWK would be the more powerful.
the only advice i would give you would be get a dellorto one, or get a stage6 one that made by dellorto. the price difference is not much but the quality difference is much better. i have had cheap carbs with blocked ports you dont get that with dellorto.

the Dellorto VHTS i cant link because the cheapest supplier cant be linked to on this site and i dont want to put you off by linking some stupid over priced site, but the VHTS is around £100
Stage 6 £85 - http://www.pedparts.co.uk/product/1122/stage6-rt-mk-ii-pwk-racing-carburettor

 

also just so we know a 24mm VHTS would rape a 25mm stock dellorto. but on the runner 172 i would have to use the 28mm power jet one.
use the power jet one as MPG will go up when your not at full revs because you run a smaller main jet over the none power jet type.

 

Why do most people use dellortos on these bikes if you can get a better one on ebay for like £30? The VHSTs are basically an improved version of the PHBs and cost like 3x more so thats an obvious one but surely they arent that special..

 

if you read my message you will see i said stay away from the ebay shit and only buy delloeto or carbs made by dellorto under licence in different names . and yes flat slide carbs are that special they just are. you will see ZERO race bikes with normal(D or O slide) carbs

if you think a PHBs is the same as a VHST then you have just shown your a idiot that should not be giving advice in this category.

i dont want to say the 25mm dellorto is a bad carb but if your looking for power/performance then yes its a bad carb, you would be needing a flatslide carb.

 

If I know fuck all then proper facts if you plz instead of 'they just are better'?

There are other companies that do flatsides atleast as good as dellorto so saying you'd only use a delly one is fail to start with tbh. And your directly comparing a 25mm to something which is newer and 2 or3 times the price (vhst)?

I asked why people used dellys on THESE BIKES. My bike ain't a race bike, your bike ain't a race bike and Mark77s bike ain't a race bike so why does racers using them make a difference?

And if you'd ever looked at the two properly for any amount of time (not meaning fullscreen google images) you'd see most the parts and the bodies of phbhs and vhsts are 90% the same..not that I ever said they were the same?

 

but the bits that matter are not the same, the carbs are worlds apart. like i said am not slating the phbh and just telling you the flat slide is better. as you like google so much google "flat slide vs round slide"

also if you think dellorto are expensive look up the prices on a mikuni and webber, dont look at the koso shite

i have a link to a dyno run testing a 28mm dell round(15bhp) vs a 28mm flat(18.33bhp) its that simple. i dont know the ruels on posting likes to other forums so i will ask before posting