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#1 Throttle linkage
Posted: Fri Mar 08, 2019 4:30 pm
by Mich7920
Hi all,
I don't find an explanation to adjust the throttle linkage.
I'm sure there is one but where can I'll find it.
Thanks for help
Mich
#2 Re: Throttle linkage
Posted: Fri Mar 08, 2019 6:56 pm
by mgcjag
Hi Mich...Service manual.....Fuel system...set up carbs......loose off the 3 pinch bolts on the throttle shaft.....adjust carbs....retighten pinch bolts.....thats all there is a far as im aware.....however other adjustable parts of the linkage just set so you have good throttle response and take out any slack........Steve
#3 Re: Throttle linkage
Posted: Fri Mar 08, 2019 8:01 pm
by Mich7920
Steve,
That's what I did, but I thought there were more things specialy about the eccentric sleeves.
Never mind, it's working as I did.
Thanks
Mich
#4 Re: Throttle linkage
Posted: Fri Mar 08, 2019 8:49 pm
by 288gto
Hi Mich,
As Steve says above but also pay attention to the adjustable cam on the bulkhead and a part that is often overlooked, the plate under the throttle pedal housing. This has slotted holes so the plate moves back and forth limiting the downward travel of the throttle pedal so as not to strain the linkages on full throttle.
I spent at least half a day playing with all the adjustments to not only get full travel at the carbs but also a smooth action. Definitely worth spending a bit of time setting it up as the accelerator is now much nicer in operation.
In simple terms, the bulkhead cam adjust the full closed position of the pedal and the slotted plate adjusts the full open position. This can then to be matched to the carb open and closed positions. The adjustment in the linkages allows you to take up any play or discrepancies. You also have the opportunity to adjust the height of the accelerator pedal.
I know a lot of people swear by the Mangoletsi conversion but a properly set up linkage system does actually work really well.
Simon
#5 Re: Throttle linkage
Posted: Fri Mar 08, 2019 9:48 pm
by Mich7920
Thanks Simon
I think you speak about a right hand drive and I didn't precise mine is a Left hand
Mich
#6 Re: Throttle linkage
Posted: Fri Mar 08, 2019 11:13 pm
by 288gto
Sorry Mich,
I was looking at Steve's post and thinking RHD. You could always convert yours to RHD
On a serious note though, the principle should be the same. If my memory is correct on a LHD you have two cams or eccentric tubes that adjust full open and close positions rather than the one cam and slotted plate.
Simon
#7 Re: Throttle linkage
Posted: Sat Mar 09, 2019 12:53 am
by PeterCrespin
Correct Simon, although an over-carpeted floor can limit fully-open too...
#8 Re: Throttle linkage
Posted: Sat Mar 09, 2019 8:49 am
by Mich7920
Thank you all
#9 Re: Throttle linkage
Posted: Sat Mar 09, 2019 11:06 am
by christopher storey
you live and learn !! I never knew about the eccentric cams - I shall now go looking at them
#10 Re: Throttle linkage
Posted: Sat Mar 09, 2019 1:10 pm
by Polse7317
+1 …..

I have also a bad pedal return after pushing it down
#11 Re: Throttle linkage
Posted: Sat Mar 09, 2019 7:46 pm
by politeperson
One thing I did find with adjusting the linkage is the importance of the throttle pedal stop bolt.
I spent hours adjusting my carbs. Perfect idle. Perfect full throttle. Perfect synchronisation.
Then I would go for a drive and put my foot down.
Come to a junction, let my foot off and then have an idle at 1,500 rpm. What is going on?
The reason was that the butterflys were shutting when I was pushing the throttle pedal down, causing tension in the rods. This was because the pedal stop was not set properly.
The tension in the rods was stretching the pinch bolt joints, in effect lengthening the linkage stopping the butterflys from closing, affecting the idle speed. Took me a while to figure that one out.
After that I set the carbs at full throttle, with the pedal forced to the floor with a stick, ensuring that the springs were still in tension when you take your foot off the pedal, so you get your idle speed down to 750 rpm.