Amal 289 setup and recommendations

Dinny

Dinny

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I'm running a standard B rap with shadow carbs at an elevation of 5000 feet altitude, some days when it's hot the density altitude gets as high as 8000 feet. I have k&n filters on and was looking for advice of carb setup. The main jets have been reduced to 170 's and one cylinder bogs down on acceleration and it just feels flat and misses when coming onto the throttle. My thoughts are to open up the cutout on the rear slide (rear cylinder is the prob) or go with a smaller needle jet (both 106). They are both currently set on the rich side as running in but maybe I'm expecting too much running at such weather extremes as its cold in the winter so I'm dealing with large changes in heat and altitude. On a hot day it's clearly running to rich which is causing the issues.

Anyone running 289's at a high altitude, if so what's your setup?

Dont tell me it's just a winter bike or cold day bike......

Thanks

Mark
 
V

vincenttwin

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Mark I live at 8000 feet yes cut the slide down but when you go lower increase the m
ain jet a wee bit.
Peter allen
 
greg brillus

greg brillus

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Try taking it for a run with the air filters off..... drop the needles down a notch or two, and maybe go from the number 4 slide to a number 5......or open up the cutaway by about 40 thou or 1 mm. Just try one thing at a time and see how it goes. It's amazing how sensitive the settings change the running of the engine, hence the rich running at higher altitude....cheers....Greg.
 
Dinny

Dinny

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VOC Member
Thanks everyone for your responses. I pulled both carbs last night and have ordered two new needles and pilot jets as they are easily 25 years old. Both slides are 29/3's and they look like they have not been modified. I will rebuild with new parts and work from there probably by opening up the slide cutouts a 1/2 size at a time and see how it goes.

I have tried it without the filters and to be honest it didn't make any notable difference but again that was a very hot day.

Cheers

Mark
 
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