qcowboy Posted February 23, 2009 Report Share Posted February 23, 2009 My TL320 ran really well when I was riding at around 4000 feet above sea level recently. When I got it home to 7000 feet, I have no power at the low end, just off idle. I tried dropping my needle to lean out the mixture. I only had one notch available to drop the needle, and it didn't make much difference. I assume I will need to change the jet(s?) and wondered if there are any high-altitude riders out there who could suggest which jets I should buy to get me close to correct mixture at 7000 to 10,000 feet, which is where I expect to do the bulk of my riding. Also, can anyone suggest a source for jets? Martin, do you carry them? Thanks for all the help you guys have been offering. The bike is coming along well, and I'm looking forward to a fun first season of trials competitions! Ted Quote Link to comment Share on other sites More sharing options...
pedronicman Posted February 24, 2009 Report Share Posted February 24, 2009 Are you in the uk? if so best place to try- http://www.dellorto.co.uk/default.asp you can buy online Original STD jetting for the 320- 90 main , 60 pilot , 70 slide , X2 needle , AV266 atomiser , 65 choke jet But most people now run 95 main and 65 pilot. See how you go! Quote Link to comment Share on other sites More sharing options...
qcowboy Posted February 24, 2009 Author Report Share Posted February 24, 2009 Are you in the uk? Not unless Ben Nevis grew a whole lot recently! I'm in the U.S., in Wyoming. I expect to do my trials riding in Wyoming and Colorado, where most of the trials range from 5,000 to 10,000 feet above sea level. I have to admit that I didn't expect to find many SWM riders on this forum who could tell me what jets work best at these altitudes, but I thought it was worth a try. I'm aware of only one other SWM owner in Wyoming. He rides a Jumbo in the local trials. Thanks for the info on factory jetting. It gives me a little better understanding than I had yesterday, and a place to start. I don't mind buying parts from the U.K. I've had great luck getting parts shipped over here quickly and cheaply. (Many thanks to Martin!) Quote Link to comment Share on other sites More sharing options...
qcowboy Posted March 2, 2009 Author Report Share Posted March 2, 2009 Can anyone tell me the correct factory float height setting? Quote Link to comment Share on other sites More sharing options...
qcowboy Posted March 3, 2009 Author Report Share Posted March 3, 2009 Hmmmm . . . no wonder it's not running so well. I opened the carb to determine what jets I have. 85 Main. Check. 65 Choke. Check. Pilot, ummm, open hole, no jet in it. I'm surprised the bike would run at all with no pilot jet. If I understand the operation correctly, the pilot jet controls the carb at idle to about 1/8 throttle. No wonder I have trouble getting a quick enough throttle response to lift the front wheel. (and no wonder the bike is so smoky at idle!) Just ordered a bundle of carb parts, including a handful of pilot jets from 40 to 60. I plan to do some tuning when they arrive. Hopefully I can get it all set up before my trip to Utah later this month. Quote Link to comment Share on other sites More sharing options...
qcowboy Posted March 4, 2009 Author Report Share Posted March 4, 2009 I found a website with lots of useful information about tuning Dellorto carbs, including pdf versions of the tuning manual, in case anyone needs it. The site also told me the PHBH float height setting (24mm). Here's a link if anyone wants to overload on Dellorto tuning info: http://www.thisoldtractor.com/gtbender/dellorto.htm Well, I removed the carb last night to set the float height correctly. Some further fiddling revealed that not only does my carb lack a pilot jet, it is also missing the idle emulsion tube that lives right above the pilot jet. I decided to try an experiment, and install a jet I had laying around from an old Honda, to see how the bike runs with SOME restriction in the idle circuit. Huge improvement. The bike starts easier now, and I can lift the front end at will. Oh, and it no longer creates a smokescreen as I pass by! I spent some time riding indoors after my fettling last night, and never felt the need to open the doors and air out the arena. Now I can't wait for the new parts to arrive, so I can set up the bike with all the proper carb parts. I have a new silencer/spark arrestor coming, which will allow me to ride lawfully on the public land nearby. While I hate to remove the original silencer, I can't find a convenient method to mount a spark arrestor onto it, so it will have to go. The new silencer is going to look woefully out of place on a TL320, but it is all I could find that would fit the exhaust pipe and also fit between the rear tire and shock absorber. The new monstrosity: http://images.dragspecialties.com/images/c...f89914f7436.jpg Quote Link to comment Share on other sites More sharing options...
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