fourex Posted July 12, 2018 Report Share Posted July 12, 2018 Hi all, I'm curious what jetting a TRS 300 runs, particularly what needle and slide they use. I'm wanting to see if it's similar or even the same as my '14 GG 300 which runs the std JJH needle. Quote Link to comment Share on other sites More sharing options...
jm_ Posted July 12, 2018 Report Share Posted July 12, 2018 Hi, 300 and 250 run with the same jetting from stock: pilot jet: 45 main jet: 125 needle: JJH with clip in middle slide: 3.5 Is almost identical in all trials engine now (maybe sherco was using a leaner pilot jet --42--) due to the almost identical thermodynamics in 2T of similar characteristics. I bet you can swap the keihin between your GG and TRS with total success! Cheers, JM Quote Link to comment Share on other sites More sharing options...
fourex Posted July 12, 2018 Author Report Share Posted July 12, 2018 Thanks, you're right, exactly the same as my GG original std jetting apart from a 122 MJ. I need to check my float height again perhaps. I only ask because my GG seems a little lean coming onto the needle and is never a 1st kick starter and I always felt this could be due to not having the best needle fitted. Quote Link to comment Share on other sites More sharing options...
paulmac Posted July 12, 2018 Report Share Posted July 12, 2018 Magic numbers on the Sherco 300 for me were 122 and 42. Cheers Quote Link to comment Share on other sites More sharing options...
lineaway Posted July 12, 2018 Report Share Posted July 12, 2018 At 6500ft in the USA. 120 main 52 pilot. Chances are the pilot is too lean. Quote Link to comment Share on other sites More sharing options...
inchhigh Posted July 12, 2018 Report Share Posted July 12, 2018 this file might help KEIHIN_SPECIFICATIONS_TRS_One_RR.pdf 1 Quote Link to comment Share on other sites More sharing options...
arnoux Posted July 12, 2018 Report Share Posted July 12, 2018 RACING and GP spec non homologated Gassers are now standard with 48 pilot (up from the 45 of a few years ago) Quote Link to comment Share on other sites More sharing options...
copemech Posted July 13, 2018 Report Share Posted July 13, 2018 4 hours ago, arnoux said: RACING and GP spec non homologated Gassers are now standard with 48 pilot (up from the 45 of a few years ago) I do believe a lot of that is to accommodate pumpgas with ethanol as well, but still the high altitude size will follow as lineaway stated. one will find these jet sizes will apply to most all bikes with that carb, as the carb only knows how much air is going through it and not which bike it is on. mixture requirements are basically the same for all. Quote Link to comment Share on other sites More sharing options...
fourex Posted July 13, 2018 Author Report Share Posted July 13, 2018 (edited) 12 hours ago, inchhigh said: this file might help KEIHIN_SPECIFICATIONS_TRS_One_RR.pdf That's interesting, because I'm old school I've always run 50 or 60:1 believing that's richer, which it is for the engine but not in carburation terms.. I need to try 80:1 as my next step. I think I know what this means, correct me if I'm wrong please. As an example, 50:1 is actually more lean than 80:1 in carburetion terms due to having less fuel but is richer in the sense of having more oil for the engine, is that right ? Running a fuel/oil mixture of 100:1 just sounds scary to an older bloke like me but it does make some sense when you think about it. PS: We don't use ethanol fuels in our bikes here in Australia, unleaded 95 and 98 is readily available. My elevation above sea level is only a few hundred metres at worst. Edited July 13, 2018 by fourex PS added. Quote Link to comment Share on other sites More sharing options...
inchhigh Posted July 13, 2018 Report Share Posted July 13, 2018 I was thinking the same, but 3 or 4 mls of oil per litre would it make that much difference ? I've heard that the verigos run at 100 to 1 Quote Link to comment Share on other sites More sharing options...
lineaway Posted July 13, 2018 Report Share Posted July 13, 2018 The clue would be even Arnoux is telling you a 45 is too lean down under. Quote Link to comment Share on other sites More sharing options...
heffergm Posted July 13, 2018 Report Share Posted July 13, 2018 Your TRS manual is pretty clear about what ratio they want you to mix at. Quote Link to comment Share on other sites More sharing options...
fourex Posted July 13, 2018 Author Report Share Posted July 13, 2018 1 hour ago, lineaway said: The clue would be even Arnoux is telling you a 45 is too lean down under. I've been running a 48 PJ and # 3 slide for over 3 years now, but it still could be better. 1 Quote Link to comment Share on other sites More sharing options...
lineaway Posted July 13, 2018 Report Share Posted July 13, 2018 My son just got a 2018 300rr two weeks ago. The dealer had put a 120 and a 58 in it. It ran well, butmy son needed it to betterĺ, so I dropped it to a 52. In your case there isno reason not to try a 50. All bikes have there own personality. , Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted August 11, 2018 Report Share Posted August 11, 2018 3.0 slide is best. Quote Link to comment Share on other sites More sharing options...
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