High Altitude Fix For Carb'd '03 T100

I'd be surprised if it really makes much difference at that height Eli, it is above 10,000ft where it gets a bit tougher. At 18,000ft you are on about half O2 content. Don't know about additives though I'm afraid.

 

I agree at that sort of altitude it shouldn't make that much difference just dont be loading the engine up too much you could also use one stage (edit sorry meant hotter plugs) if your worried way easier than re jetting.

 

‘Standard’ carb settings are optimised for sea level up to 3,000 ft. Equally standard thinking says drop about 5% in jet size for elevations of 3-6,000 ft.
You might find the attached useful.
http://www.bonneville.se/nedladdning/Hur man jettar.pdf

 

I have much the same conditions here. My main residence is about 3040' according to my GPS. My vacation home is just over 6200'. If you make changes to your jetting, don't go too rich. Otherwise it will not run well at the higher elevation. Changing octane will NOT help. Higher octane is required, only if your compression is increased. These engines are set up for mid-grade fuel. I would stick with what the factory engineers spec. out unless you have done some engine mods that raise the compression. If you raise the compression, you should also shorten the ignition advance curve. ...J.D.

 

Higher altitudes tend to make already rich mixtures richer because the air is thinner IE less dense therefore requires smaller jets to compensate.
Most EFI will self compensate due to usually using air density or pressure measuring.

 

This is an excellent thread, Eli. I have been wondering the same with it being about 3500 here in Artesia and about 8000 (I think) up in Cloudcroft where the twisties are. This is helpful.

 

Hopefully sometime before winter I'll get a chance to see how she runs up there. It's only about an hour and a half away, I just need to take a Saturday and do it.

 

All the newer carburetted Triumph are set up brutally lean from the factory. Over the years I have rejetted all three of mine. People usually rejet when they change to an aftermarket exhaust. But what most people do NOT realize is the airbox is quite restrictive. In the old days [pre-fuel injection] it was not uncommon to see a hole cut in the side of an airbox. My buddy had to do this on his Honda CL350 when he moved from S. California.to Ogden, Ut. @ 4000ft. .[A few yrs. later he moved home and brought the bike back with him]. It is also.common practice among those of us riding the old carburetted Triumph triples to modify airboxes [sometimes extremely]. But airbox and exhaust changes must be finalized BEFORE jet sizes.are.determined. …J.D.

 

May do but not by much try the hotter plugs however you would still need to return to the std heat range at lower altitudes although if you just go one stage hotter you should be fine if that is enough to avoid fouling due to over rich mixture.

 

Do you know if the ignition units run knock sensors on the later carb versions? if the factory setup is that lean then i wouldn't worry about high altitude...will probably perform better in that case.

 

Well, if I get to ride up there, I can help with that. The previous owner removed the airbox and installed K&N air filters. I think he also rejetted it for the after market exhaust he installed, too. I bought it in Albuquerque but I don't know what the altitude is there. It runs great here. I will make it a point to post what happens when I ride up to Cloudcroft. I don't know when that will be, though.

 

There are no knock sensors on those bikes. I also do not.like the fact the the ignition advance and timing is fixed at the factory. The big problem I see with most guys is they make too EXTREME changes. Stock Triumph jetting is usually good to about 5000' from what I have experienced. You can stretch it beyond that, but, I set my idle speed up and just live with the fact it is a bit rich. I have a carburetted triple that I set up a couple of years back that still has a stock exhaust. I bought a new airbox because the previous owner had totally destroyed the original one. I cut the new box the way I wanted it, then installed jets I knew were too rich. I then took it out and ran it and lowered the jet size to what works the best. She runs great. ...J.D.

 

If it works well, leave it alone. ...J.D.

 

Eli Hardof
Welcome to the family and so glad the bike behaved. Now there's no stopping you. Go do it and have fun.
Regards
Joe.