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Bike carb weight
DarrenW - 13/7/07 at 01:29 PM

Ive just assembled my carbs onto manifold and fastened filter on for first time. Im surprised at the weight of it all. Has this raised concern for anyone else? Just wondering if anyone has felt the need to rig up a support or similar. There is a fair amount of leverage being exerted on the manifold. The manifold itself is light (Ali) but quite substantial but the head studs will be taking a fair load.


I havent tried it on engine yet - maybe nothing to worry about. Rescued attachment 12072007136.jpg
Rescued attachment 12072007136.jpg


matt_claydon - 13/7/07 at 01:37 PM

One M8 bolt has a yield strength of nearly a tonne, so you should be OK


BenB - 13/7/07 at 02:04 PM

I'd bracket it- with the length of those manifolds plus the weight plus vibrations, problems are a strong possiblity. A cracked block would not be fun....


mark chandler - 13/7/07 at 02:07 PM

I guess you have not tried the weight of some twin 45's then, bike carbs will be light by comparison.

No need to worry.


DarrenW - 13/7/07 at 02:15 PM

Thats true - i have no experience of twin 45's. Im sure the manifold will be Ok and no risk to the block. The filter isnt particularly heavy either despite its size. i havent seen anyone else bracket theirs and TBH wouldnt know where to start.

The manifold isnt overly long, pic makes it look worse. (approx 100mm from carb to mounting face).

Its probs not an issue. Im not surprised some people have found the carbs pop off the rubbers at times!. Mine seem very secure at the moment.

I might try and fit big washers or some shaped 3mm steel load spreaders behind the head stud nuts.


Only concern now is how much of the bonnet ill have to cut away to get it all to fit. Ive got the float level line virtually horizontal which makes the carbs and filter sit quite high.


jacko - 13/7/07 at 02:42 PM

YES i have just to support the carb to manifold to stop the carbs coming out the rubber pipe .
Roadrunner on here had to do this as well i think he has photos in his archives
Graham
PS Darren are you doing the drag day

[Edited on 13/7/07 by jacko]


worX - 13/7/07 at 02:44 PM

Twim 45's etc would be weightier!

plus your manifold is at an angle to help in a small way!

Is it just the pic or does the manifold plate appear to be bent slightly at this near side?

Steve
ps Darren, are you still interested in that vice?

[Edited on 13/7/07 by worX]


DarrenW - 13/7/07 at 03:01 PM

Has roadrunner called them carb ties? Look more like to stop the carbs popping off rather than extra support.

The flange plate isnt perfectly flat but is exaggerated in the pic.

Im happy that the line on the side of the keihins is horizontal but they will stick up a fair bit. Im now scared to put them on the car as this will reveal just how much they will stick out by!! I probs wont be able to resist tonight after a few shandies!!


I forgot about the Vice - remind me again



i wont be at the drag day - too much on. Dress needs dry cleaning as well


jacko - 13/7/07 at 03:12 PM

quote:
Originally posted by DarrenW
Has roadrunner called them carb ties? Look more like to stop the carbs popping off rather than extra support.

You are right to stop them popping off but it supports them as well i did mine different to that i used 1/8th welding rod
Graham



[Edited on 13/7/07 by jacko]


Ratters - 13/7/07 at 05:31 PM

quote:
Originally posted by mark chandler
I guess you have not tried the weight of some twin 45's then, bike carbs will be light by comparison.

No need to worry.


Exactly what I was going to say


jacko - 13/7/07 at 05:51 PM

quote:
Originally posted by Ratters
quote:
Originally posted by mark chandler
I guess you have not tried the weight of some twin 45's then, bike carbs will be light by comparison.

No need to worry.


Exactly what I was going to say


Yes but twin 45 are bolted on bike carbs only push in rubber pipes with jubilee clips on them


mark chandler - 13/7/07 at 08:45 PM

The question was leverage on the manifold, not on the rubber bits.

I have never had any of my bikes drop carbs and they are not supported. They do however have a grove on machined at each end and a lip on the rubbers, that includes motoX bikes.


Ratters - 13/7/07 at 08:53 PM

quote:
Originally posted by jacko
quote:
Originally posted by Ratters
quote:
Originally posted by mark chandler
I guess you have not tried the weight of some twin 45's then, bike carbs will be light by comparison.

No need to worry.


Exactly what I was going to say


Yes but twin 45 are bolted on bike carbs only push in rubber pipes with jubilee clips on them


Yes I know. I thought you were comparing the weight of the two??


Fatboy Dave - 14/7/07 at 02:31 PM

quote:
The flange plate isnt perfectly flat but is exaggerated in the pic.


You'll never get them to stay straight during welding anyway.

12mm thick plate takes a lot of preheat and a fair few amps to weld. Even bolting down to a flat bench mind still warp slightly.

They do stay quite flexible though, and you can actually bend the flanges by hand...


Uphill Racer - 14/7/07 at 11:32 PM

Ok DA here...........carbs........like liberty bodice............dont work, hold in what wants to get out. I cant make a carb, but have made throttle bodies........easy......wake up guys n smell the exhaulst.....


DavidM - 15/7/07 at 05:54 PM

quote:
Originally posted by Uphill Racer
Ok DA here...........carbs........like liberty bodice............dont work, hold in what wants to get out. I cant make a carb, but have made throttle bodies........easy......wake up guys n smell the exhaulst.....


Sorry, what did you say?


rusty nuts - 15/7/07 at 07:07 PM

Have found the silicon hoses that I used to fit bike throttle bodies tends to let them creep off of the manifold . I am going to fit some "stays" to stop creeping.


Uphill Racer - 15/7/07 at 11:11 PM

throttle bodies dont need remote mounting