PHBL 26mm jetting starting point

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Monty
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Thu Jun 05, 2014 2:47 pm

Ok corrado im not helping much. It is a BS I understand that indicates what side the airscrew is.
It apparently came off a reed blocked 2 stroke Fantic 250. Looking at the bristol lambretta site it does show the attomiser having cross drillings for 4 stroke but it says when you read the bumph it seems to imply that all the carbs will run 2 or 4 stroke depending on how they are set up.it mentions the power jet as giving extra fuel when the throttle is opened quickly. It looks like it has an extra tiny hole after the slide.

YAMLAM
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Thu Jun 05, 2014 5:08 pm

its worth a look on the Delorto website. I bought a PHBH 26CS off a mate, Delorto`s site says it comes off a Montessa 250( two stroke) but it comes with a 4 stroke bush in the centre, easy enough to change but it runs a different type idle jet (idle emulsion tube ) to what we are used to in the Lammy world, and there are 16 different ones at£6.25 ea plus vat as opposed to £3.25 for a standard pilot jet. could be a costly exercise unless you know someone running a similar set up.
worth a read thou.......http://www.dellorto.co.uk/merchandise/p ... ctionID=20
win or lose have a booze

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Monty
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Thu Jun 05, 2014 8:49 pm

FFS I should not post while at work.
OK looks like I have an odd ball. IT is a PHBH26 NS
It has a raised attomiser sheild like http://www.dellorto.co.uk/images/parts/9198.jpg
Not the flush ones that are listed as 4 stroke
Its got separate floats that run on 2 rails each side
the 125 main will be too big but I will go for a AV268 105 an x7 and a 45 pilot and block the tiny jet and see what happens. it can not be any worse that the Spitting Jetex, that is slightly better than it was but still makes it hard to start when warm.
The price I got it for is still good even after buying the bits and bobs. it can always go back on ebay again :mrgreen:

itwillrunproperly
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Fri Jun 06, 2014 1:27 pm

doesn't the PHBL use the D type needle?, if its made for a 4-stroke the atomiser would be flush with tube, I use a PHBL 22 BS, with a D22 needle, 2nd clip, standard 40 slide, AQ264 atomiser, 115 main,50 pilot and 60 choke, I had some probs when she'd wind up statically but when I tried to ride no guts at all and she'd die on me, so I changed to a larger main jet from 105 to the 115, now seem to be ok but I haven't run her in yet also changed the cable choke to a flip one as I couldn't stand to sod about with the cable one for much longer, it has to be rubber mounted which is better I presume, don't know if this helps or not, haven't done any plug chops either as I still got 468 mls to run her in:-) Amazingly enough done 32mls without a hitch, picks up nicely in 3rd and 4th.

(I'm running a 200cc small block conversion, BGM stator, CDI and Regulator, SIL Flywheel, 42mm bigbore, 5 plate 10x spring clutch :-) sx150 G/B, MB inlet Manifold, 18/47 Main drive, standard airbox with several holes drilled in and bridge piece removed from air scoop) I took her up to 55 Lambretta MPH and still had some juice left should do at least 90 Lambretta MPH! :lol:

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jonny snatchsniffer
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Fri Jun 06, 2014 4:59 pm

yeah the 26phbl does use D needles and the aq atomiser, d22, d26 and aq264 is a good start

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corrado
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Fri Jun 06, 2014 7:24 pm

We've at least established that it's a PHBH. [of sorts].

Stick it back on fleabay and save yourself a holed piston[s]*.
* delete as appropriate.

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Monty
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Fri Jun 06, 2014 11:11 pm

Yes its developing into one of those don't let the bugger get to you moments. I may add that Im not the type to just follow the trend and buy my way out of trouble, I may be crying in the red wine but give it a go...
Got an AV 266 atomizer as my local dealer looked at the list of requirements and went are you mad....
I want to run this through an air box that got a "it wont fit". It turns out the 42mm inlet is 2mm smaller that the rubber I had fitted to my Jetex. without the plastic flange Venturi. It should pull up with a clip.
The atomizer was around 4mm shorter than the x drilled one and hit the stop flange on the carb. F*** it I drilled out the carb to allow the atomiser to screw in. its 4 mm further up the tube than the other one.
He reckoned my 45 pilot was way out and recommended a 50 or 55
with a 110 or 115 main and an x7
Now as far as I can see this black mans magic seems to come down to the size of the atomizer, (2 stroke ones don't seem to have cross drillings) then its the size of the needle eg little cock in a big hole :lol: . Pilot 45 or 50 and I will leave the choke as its is.
He who dares holes a piston

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Monty
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Fri Jun 20, 2014 8:51 pm

Well the saga continues. What with working away all the time and the bloody postman who refuses to leave any package with my neighbours its taking forever.
My bit above about making it fit was a bit previous. The first manifold was a strait out one and as I said I had to shave a bit of the gasket face to clear the frame. I then found the carb was fowling the head cowling and the carb was getting dislodged. If the float overflow had not come out the bottom it would have been better. Anyway. Went for another manifold an AF one. These come out at a steeper angle. Now this has the bolt head close to the frame but its not on it. next the carb sits a good inch above the cowlings, Now I see why "no way will it fit"..... it will if I do away with the air box. NOW THIS IS NOT WHAT I WANTED.
So im forced down the no airbox and an external filter. Got a ram air one on the standard rubber. yes lots of room but the bloody induction noise is what kept me with the Jetex for so long.
So after butchering the 35 slide with the dremel It was ticking over but ran on a bit when the throttle was shut so I presume it was running lean. So I got a 40 slide.
Next problem is the tickover screw is all the way in and it will just tickover but only just. It starts good on choke and lets me turn it off soon after without cutting out if I just raise the revs slightly. Its got a 53 pilot in at the moment but I have been up to a 65 and its the same. The air screw doesn't seem to do a lot. not like the Jetex when you can feel and hear the sweet spot. I can put a bit of tension on the cable to lift the slide off the stop but thats not ideal, is it?
Any ideas guys.
Any way of getting rid of that rasping induction noise or will I get used to it

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tea5ive
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Fri Jun 20, 2014 10:18 pm

have you bought or changed any jets in your carb ?. if its one from a trials bike they have longer or deeper jets (idle and choke) which let them sit lower in the float bowl , just another thing to be aware of ;)

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Monty
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Fri Jun 20, 2014 11:11 pm

tea5ive wrote:have you bought or changed any jets in your carb ?. if its one from a trials bike they have longer or deeper jets (idle and choke) which let them sit lower in the float bowl , just another thing to be aware of ;)
The idel jets I have been buying seem the same. Choke is a 60 it has an O ring round the end and sits in a recess in the bowl

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