Anyone following my build thread will have seen I removed engine to go to twin weber 34ICT. I had a really relevant reason , or so I thought, and of course hindsight and may hard come by £`s later it yet another case of 1 step forward and six back    I thought clearance would be an issue but never thought it be so bad.

Anybody that ever considers fitting twin 34`s with CB Performance manifolds and hex linkage to a Manx forget it unless you are prepared to add two blisters to the Manx body.  Having just refitted the engine, and note this cannot be done on my Manx with the linkage in place, the hex bar arms that actuate the carb throttles do not have room to operate thro` their curve at all. They will not fit in the gap between the shroud and Manx tub at all. My Manx is very non  - symetrical, something that has become more pronounced as the years have passed. The lack of clearance is more pronounced on one side than the other. (This could also be due to me not having fitted the body precisely along the chassis axial centre line but I doubt that ).

I cannot bring myself to cut body slots to allow the arms to move thro` a full stroke and fit fibreglass "blisters and then try to match gel coat colour. That to me is a step beyond sanity.

So I am going to spend more state pension monies and try another linkage version that`s sits down towards the block. At least that`s my initial thought but it will mean moving coil back to the fan shroud which is a shame and maybe having to re-route ignition leads. Going to give my self a few days break rather than rush headlong into this. (I am never going to get saved up for a hood at this rate  )

Whilst I lie at wake at night, once again and ponder things, I would be grateful if you guys out there with non high level "hex bar" linkages could give me some thoughts on whats available, what you have fitted along with any pro`s and cons etc. The more stable and reliable the central support the better I would hope.

Any pictures as I`m not quite sure of the problem?   

CSP do a nice bell crank linkage, which will solve your problem! but they are £130 or so. Yes the Hex bar linkage on the 34ict's are not the best and if you knock them, it can spoil the silly little mounting screws. Hopefully you haven't got tall air filters as well, cause that might be an issue. But you can get different shorter ones

Rob

Rob.... why didn`t I speak to you......   Yes, not only do I have tall filters I have tall manifolds, (the full kit)... The filters and tops go on with a bit of a squeeze nearside.....  The offside... just had to give me a kick in the pants didn`t it.  Filter fouls the wiring support I have on my buggy. (That`s get round able but so disheartening).    When I first saw this kit I thought it was well thought out and substantial but it does have these niggles.

The CSP kit is what I have in mind at the moment but can you advise here.... On line video`s show the inner helm joint on offside rod fouling the bottom left alternator fixing bolt. They advise the additional "return spring" also... again at additional cost. Other than this the reports seem favourable.  I do know what both these items total to cost wise ... I just need to get it right this time.    I am about to add photo to show Dave what I am meaning regarding arm clearance issue re Manx.

Dave... I cannot get a really good picture. Any additional lighting just reflects back of the black surfaces...

The hex rod is rotated around by throttle cable. There is an arm on hex rod that pulls connecting rod to carb throttle spindle up and down. At rest, or idle this arm is approx horizontal and then goes in a downward arc to full throttle.

The arm in picture is not even in position. It cannot be put up to horizontal to fit to zero throttle position due the the lack of gap between the arm end and the rear droop part of the body tub. Hopefully the photo is clear enough to show the total lack of clearance. It doesn`t look like much more clearance is required in photo but the arm needs to fit horizontally

Just looked at the photo.... It seems to show that just a little more clearance is required but that must be the angle of the photo...  A lot more is required, especially on this the offside. The arm travel needs to occur with the arm right up into tub. 

Have you screwed the little rods in to their maximum? if they still have threads showing, you might be able to get the clearance you need if you cut the possible 1/2ins of spare thread off!. Yes on some engines not all lol, it didn't on the last two I built but the CSP bell crank can foul on the bottom passenger side fan shroud bolt!. if it does just take it out, it will be fine with 3 lol

Rob

Cheers Rob.... I have tried to stop "over thinking" in the hope my patience returns. Initially I thought that I may be able to recover some expense by trying to sell the CB linkage and maybe filter housings but in my experience you pay retail cost and end up selling for a fraction of the initial outlay. Your help is appreciated. 

Out of the box idea use the linkage and move the body back on the pan to get clearance

Looks close so easier to get a centre pull bell crank set up or a solid side pull rod set up

Sure I have mentioned hex assembly fouled on my Doon and I used CSP crank. Took the washer out from the housing bolt and doesnt foul

Hi Doon yes you did mention fouling. I read that after I had bought the CB hex`    When I first took a look at the bits in its packaging the size of the 3 arms did stand out. I had engine out and fitted carbs etc and looking at things I was hoping it would be ok. It was soon obvious that I wasn`t even going to get the engine back in with bar and arms on but I didn`t expect the fouling to be as bad as it was when I tried refitting them. The photo is with the hex bar and arms right down and accelerator arm round against the shroud and there is just no room whatsoever. 

A quick question. My throttle pedal/cable operate freely with no snagging at all. Do you think I will need the additional spring to fit to the pillar section ?Both my carbs are new and the return springs effective on them.

Careful with extra springs as you end up with a harder pedal that does not go from idle smoothly but suddenly snaps open as the foot pressure increases.

Cheers Keith   Just wondered why this option is offered alongside the csp linkage, albiet as a separate entity. With my standard pict3 I didn`t need any additional spring assistance.

Well, at times, isn`t life strange   ??

As I perused the web experiences of others that may crop up with twin carb linkage fitting here is what I came across this morning.....  They say a picture paints a 1000 words and that is true.  This is what I tried to describe in words regarding fouling of the CB Hex linkage. Is this an extreme solution ?... I am not sure   

Hopefully with those filters the carbs have built in ram pipes like later 40DCNF webers and not flat tops or there may be a bent connecting rod starting after heavy rain as water does not compress.