iconic558 Posted October 24, 2016 Report Share Posted October 24, 2016 (edited) Was at a classic trial yesterday and I noticed that some 2 strokes 'four stroke' at idle and some don't. My TL320 SWM always four strokes at idle, is this usual? cheers guys Edited October 24, 2016 by iconic558 Quote Link to comment Share on other sites More sharing options...
axulsuv Posted October 24, 2016 Report Share Posted October 24, 2016 HUH ??? Explain Quote Link to comment Share on other sites More sharing options...
b40rt Posted October 24, 2016 Report Share Posted October 24, 2016 (edited) I've had several Rotax engines bikes, none have four stroked. Edited October 24, 2016 by b40rt Quote Link to comment Share on other sites More sharing options...
turbohead Posted October 24, 2016 Report Share Posted October 24, 2016 Please, give us a recording, just to be sure what you mean! Quote Link to comment Share on other sites More sharing options...
baldilocks Posted October 24, 2016 Report Share Posted October 24, 2016 He means the bike is spluttering as it's a little too rich. Usually either pilot jet or needle is wrong. My swm wouldn't rev but was fine everywhere else in the Rev range Quote Link to comment Share on other sites More sharing options...
racey Posted October 24, 2016 Report Share Posted October 24, 2016 Discussed my SWM with factory rider Giavani Tosco (I think that is right) at the 78 SSDT and he said I should reduce the amount of oil in the fuel as they didn't need as much as the Monts Ossas Bultos of the day. Did this and it ran perfect from then. From memory I reckon I must have been running at around 40/1 at the time and he said 80/1. Too worried to go that far I think I settled for somewhere in between and that fixed it for me. With modern day oil technology you could probably go a bit further, so it might be worth going down that route if you are currently on a low ratio. Of course the carb is always there to be tinkered with.... Quote Link to comment Share on other sites More sharing options...
b40rt Posted October 24, 2016 Report Share Posted October 24, 2016 (edited) 80:1 in ssdt in 78 ! Pretty sure they run 50:1 now ...... Edited October 24, 2016 by b40rt Quote Link to comment Share on other sites More sharing options...
lineaway Posted October 25, 2016 Report Share Posted October 25, 2016 Funny, I was just working on a fairly new bike today that was four stroking at idle. The rod for the choke was bent just enough not to let it sink home. Good luck on your problem. Quote Link to comment Share on other sites More sharing options...
suzuki250 Posted October 25, 2016 Report Share Posted October 25, 2016 (edited) 80:1 on an air cooled bike will definitely stop it four-stroking, but it will also stop it two-stroking! Edited October 25, 2016 by suzuki250 5 Quote Link to comment Share on other sites More sharing options...
pschrauber Posted October 25, 2016 Report Share Posted October 25, 2016 To the mixture I use between 1:66,7 - 1:71, which is around 75 - 70ml of oil to 5l of gas with no problems? (gas: 102 ethanol free pump gas or Aspen fuel, oil: half synthtetic IPONE or Plutoline trials). To the stroking you might please check: - air filter foam which might be clogged or over oiled or to dense (I personal use as little as possible, soak the filter first in oil but then squeeze immediately all out again, which leaves an oily coating and a good air flow) The airfilter should be a bit thicker than standard, (around 15mm instead of 10mm or less), good stuff: http://www.wms-online.de/product_info.php/products_id/1330/name/Luftfiltereinsatz_Malossi_-_Suzuki_Burgman_400.html ) - wrong slide?, (should be 60), - worn slide and thus needle and needle jet?, (X2 for needle and 266AV for needle jet), - wrong jets? (main 90 and pilot 60) - check fuel screw, screwing in means lean, screwing out rich, just the opposite to many SuHonYamKas ... Quote Link to comment Share on other sites More sharing options...
suzuki250 Posted October 25, 2016 Report Share Posted October 25, 2016 I run all my air cooled 2t bikes at 40:1 without a problem, no smoke and no plug fouling.... Quote Link to comment Share on other sites More sharing options...
pschrauber Posted October 25, 2016 Report Share Posted October 25, 2016 I run all my air cooled 2t bikes at 40:1 without a problem, no smoke and no plug fouling.... Cool, that's how mine fumes with 1:50! Quote Link to comment Share on other sites More sharing options...
iconic558 Posted October 27, 2016 Author Report Share Posted October 27, 2016 Cheers guys I'll try and get a video up of her idling. Quote Link to comment Share on other sites More sharing options...
iconic558 Posted October 27, 2016 Author Report Share Posted October 27, 2016 Sorry forgot to mention other than the idle four stroking she carburates sweet as and picks up from nothing and will chug up hill on idle to.....revving out she sounds like she is running a little lean if anything. Running 50:1 full synthetic Putolene no excess smoke. The carb was brand new before I bought her so I need to check specs. Quote Link to comment Share on other sites More sharing options...
reginald Posted October 27, 2016 Report Share Posted October 27, 2016 Cool, that's how mine fumes with 1:50! It might be sucking a little gearbox oil through the inlet tube between the carb and the rotary valve? Quote Link to comment Share on other sites More sharing options...
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