Just wondering if anyone here is aware of what is involved in converting a PHM40A/D to PHM40A/S? I'm planning to restore these carbs and figured I might as well convert one to a leftie while I'm at it, that way I end up with a restored matching pair. Any experience with conversion out there?
Cheers,
Geoff
Converting Right to Left PHM40
Re: Converting Right to Left PHM40
Jeez Geoff,
At the risk of me looking like a Dill for the second time, just a little confused. Do you currently have 2 PHM 40 A/D's and want to make one of them an A/S ?? ( Oh, and I did read the heading this time Ha Ha !!)
Cheers
Rick
At the risk of me looking like a Dill for the second time, just a little confused. Do you currently have 2 PHM 40 A/D's and want to make one of them an A/S ?? ( Oh, and I did read the heading this time Ha Ha !!)
Cheers
Rick
I have desmo disease, I just hope they never find a cure !!!
Re: Converting Right to Left PHM40
My carbs are buried at the moment but if memory serves I think all that would be required is to drill and tap the existing bosses on the carb bodies. The hole for the mixture adjuster might be a problem if you don't get the diameter right and the depth would have to the same as the orig. hole. Plugs for the old holes would be easy to make. Or find the other person in the world with two lefties and swap them.
Re: Converting Right to Left PHM40
Hi Rick, yes I might have been a bit unclear - I have two AD (right side) carbies and I want to make one of them an AS (leftie)
Geoff
Geoff
Re: Converting Right to Left PHM40
I reckon you're right about drilling the holes, hole depth and diameter will be the key, thanks for the reply. I'll see if I can find a carby wizard locally or take it to my machinist mate.
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Re: Converting Right to Left PHM40
I'm just imagining the confusion that will ensue when someone who knows about these things sees a carb with AD on it where there should be one with AS ....
1974 Ducati 750 GT
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Re: Converting Right to Left PHM40
So, you want to put PHM 40's on a 750 GT? Probably not the wisest of choices there.. I'd say PHF 36 is the biggest you should go.
Steve Allen (925)798-BEVL[2385] Ride'm, Don't Hide'm
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Re: Converting Right to Left PHM40
Hi Steve and thanks for your comments, perhaps I should have mentioned this '750GT' was converted to a replica of the '74 supersport model. The motor was rebuilt with new big end, sport pistons and currently has Darmah heads with 32mm pumpers. I'm restoring the 40mm carbs so that I have the option of whacking them on later - but to be honest I'll probably keep them aside for a while since the smaller carbs give the bike tractability for pleasurable riding. If I ever sell the bike I'd put the 40s on it then, or a more original matched pair if I stumble across them.
Last edited by GeoffW on Mon Apr 15, 2013 1:52 pm, edited 1 time in total.
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Re: Converting Right to Left PHM40
you will need to change the intake manifold as well as the throttle cables when switching from PHF to PHM carbies - FYI
Steve Allen (925)798-BEVL[2385] Ride'm, Don't Hide'm
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Re: Converting Right to Left PHM40
Re: conversion - Steve, when putting the PHM40s on, does it necessitate head mods such as widening the stud spacing and opening up the ports or are there 'bolt on' 40mm manifolds for Darmah heads still available? I seem to remember talk of alternative ways of going about the 40mm conversion but it's over 20 years since I had a bevel twin...and I'm a little foggy!
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Re: Converting Right to Left PHM40
it is very difficult to find narrow spacing intakes with the right OD for PHM.....
Steve Allen (925)798-BEVL[2385] Ride'm, Don't Hide'm
Ducati/Euro Spares -> https://Store.BevelHeaven.com
Re: Converting Right to Left PHM40
Thanks Steve, I'll cross that bridge when I come to it.
Cheerio,
Geoff
Cheerio,
Geoff
Re: Converting Right to Left PHM40
The 32mm are really more than big enough for normal riding especially if it is still a 750. Even on a hi comp 900 the 40mm were on the edge of usefulness unless it was on a race track.
Re: Converting Right to Left PHM40
Pretty sure the 40 mm inlet manifolds that were on my narrow inlet Darmah have just had the locating holes slotted to fit .
I can take a pic and send if interested.
I took the 40's off and put 32's on.
won't be until next week as all efforts are towards Bevels and Bullshit ride this weekend
I can take a pic and send if interested.
I took the 40's off and put 32's on.
won't be until next week as all efforts are towards Bevels and Bullshit ride this weekend
Re: Converting Right to Left PHM40
Bill, thanks for comments - I recall my Darmah used to pull really nicely with just 32mm carbs, so you've confirmed what I think I'll do i.e. just ride the bloody thing as it is and save the 40s for when I sell it or when my wife sells it after I die or get too old to know what the heck that green & silver motorcycle is doing back there in the shed! Actually it would be a lovely thing to leave my son when I grow too old to ride.
Garry, I'd certainly be interested in seeing pics of the slotted manifolds. One question (for anyone) - where the ports at the gasket on the 32mm Darmah heads the same size as the 40mm Darmah heads?
Garry, I'd certainly be interested in seeing pics of the slotted manifolds. One question (for anyone) - where the ports at the gasket on the 32mm Darmah heads the same size as the 40mm Darmah heads?