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Triumph TR6 - Carburetter temperature compensator solution
Last summer an erratic behaviour of my TR6 was caused by temp. compensator, according to a TR6 'specialist' in my area. He told me that it is a bad design adopted by Stromberg to complie with anti-pollution devices and to replace them with new ones will not solve the problem. If they are such a flaw for TR6, is there a solution to get rid of them and have carburetters working decently.
|J. G. Catford|
As I recall, these are a very simple bi-metal mechanisms that either work or do not. I know that these were used on the '69 TR6 and I believe the -250 series as well. I have been the primary care giver to a '74 & '75 since new. I rebuilt the carbs on both in 1990 and have never had a problem with these components. The originals are still in place.
I might call the design antiquated by todays standards, but not bad. As a matter of fact, I do not recall anyone ever encountering any issues with these parts. Of course I may have been living under my rock for too long now.
I know that there are several good articles on the web for this adjustment and it was simple to do while I did a full rebuild on my carbs.... spend a few evenings and do a complete job after doing the research... there are several seals, passages and valves that need to be carefully inspected and likely rebuilt. Take your time and have some fun!
This article should help somewhat:
Take care, Rob
There is also an article on the VTR website detailing the adjustment and balancing of the temp compensators. I essentially followed the VTR article and it worked well. I did have to lightly polish the plastic piston that moves in and out of the bore controlling the air flow as mine were binding as the bi-metal tab was shifting. I also polished the internal aluminum bore walls as well for good measure. Get yourself a good candy thermometer with range from at least room temp to about 190'F. Key is to have both of them open progressively at the same temps and to be both fully open at the same or very similar temperature. Do not rush this job as it took me about 2hrs+ to get it right. I found it easier to check and adjust them as my pan of water was cooling off (with ice cubes) at a slow rate than to try to adjust them while heating up the pan of water on the stove.
I will folow your suggestion and be meticulous with a lot a patience in rebuilding them. But that bi-metal stuff have never gave me a good inspiration.
|J. G. Catford|
|I HAD TO OPEN MINE ALL THE WAY ALONG WITH THE MIXTURE SCREW FULL OPEN SO I COULD GET RID OF RICH AT IDLE. STILL TRYING TO GET ENOUGH FUEL AT WOT. NEW RINGS AND HI-PERF CAM AND HEAD ALONG WITH PHOENIX exhaust- THESE CARBS ARE BARELY CUTTING IT.|
|I disabled the temp compensators when the 3rd Z-S was installed - tightened the screw down so they won't open. The 3rd carb doesn't have one, anyway.|
Steve - I'd start by raising the fuel level in the bowls in 2mm increments. That should let you get into adjustment with the needle and provide more fuel at WOT. I also have settled on ATF for the dampers. Good to hear you're almost on the road.
|GOOD IDEA BRAD. I GUESS IF I FINALLY GET ENOUGH FUEL AT WOT I CAN ALWAYS REMOVE THE GUTS OF THE COMPENSATORS TO LEAN OUT THE IDLE ENOUGH. ANYONE KNOW WHERE I CAN GET SOME SPACERS TO PUT AT THE TOP OF THE NEEDLE TO RAISE IT UP A LITTLE ABOVE STOCK HEIGHT IF I NEED TO GO THAT ROUTE?|
As to your wot lean issue. you can order B1AQ needles from Burlen (UK) that are around 15% richer on the top end. This is of course applicable only if you have adjustable needles. For fixed needles order the B1AR which is around 20% richer at wot. Go to Burlen.UK for further info and order instructions. HTH
Mike '71 TR6 Z-S Triples
This thread was discussed between 03/01/2006 and 08/01/2006
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