shannonpurdy Posted March 5, 2004 Report Share Posted March 5, 2004 I was reading in the FAQs section about jetting. I can see how temperature would have an effect on fuel air mixture, but who wants to rejet for a 20-40 degree tempertaure difference? I also know that your pre-mis can effect the fuel air mixture. Lets say at 60 degrees you jet with a 32:1 mixture and as temperature rises during the summer months to 85-95 degrees you switch to a 40:1 pre-mix with the same jets. It makes sense to me, you guys see any holes in my theory? Quote Link to comment Share on other sites More sharing options...
Stuff Posted March 5, 2004 Report Share Posted March 5, 2004 I understand your idea on premixin to compensate for changin temp but do you know for sure if they are directly related.......meaning switching from 32:1 to 40:1 will ideally suit the engine for a 30 degree temp change?? You can't be too sure. There are many factors that can influence jetting and its better to be safe than sorry. Check your plugs, do plug chops and keep up on the maintenance. 2-strokes a very senstive and you gotta want to tinker to keep it runnin good. Quote Link to comment Share on other sites More sharing options...
PlaynSand Posted March 5, 2004 Report Share Posted March 5, 2004 I have tried chasing the temps around by changing ratio from 40:1 all the way to 80:1 with synthetic oil . When we are at the dunes it could be 80 degrees in the day and at night drop to 50 degrees and mine would always get a little slugish in the cold. Changing the ratio helped some but ended up being a major pain in the @@@. Having two ratios of gas around and trying to remember which one was which , draining out some fuel to add the other. I soon gave up on this idea and just jetted for warm weather with airbox lid off and for the night rides just throw the lid on and let it run a little rich. With the guys I ride with you got to be ready to go! They will not wait around for you to change jets or mess with your fuel ratio. Their Will leave your bu@@ sitting at camp. Quote Link to comment Share on other sites More sharing options...
Ducman Posted March 5, 2004 Report Share Posted March 5, 2004 You have to make pretty drastic adjustments in the oil ratio like playnsand said since the oil is such a small part of the mix 32:1 = 3.1% oil, 40:1 = 2.5% oil, 50:1 = 2%oil. I'd say get some of those sliding vents that can be installed on the air box to increase flow. When it's hot run it w/o the air box lid. As it gets colder put the lid back on and open a vent or 2. When it gets like 40 or 50 degrees colder close all vents with lid on for maximum restriction of flow. Then as a last resort if it gets even colder go from 32:1 to 40:1 or 50:1 if your oil is designed to go that thin. Quote Link to comment Share on other sites More sharing options...
shannonpurdy Posted March 5, 2004 Author Report Share Posted March 5, 2004 I soon gave up on this idea and just jetted for warm weather with airbox lid off and for the night rides just throw the lid on and let it run a little rich. I hear ya. When I go to the dunes I go to ride. Don't get me wrong, I love working on my bike but not when it is time to ride. Controling the air flow sounds like it would be alot easier thandealing with the pre-mix mess. Any suggestion on how to do this without an airbox? I run K&Ns and O/Ws with no box. Quote Link to comment Share on other sites More sharing options...
sredish Posted March 5, 2004 Report Share Posted March 5, 2004 You have to make pretty drastic adjustments in the oil ratio like playnsand said since the oil is such a small part of the mix 32:1 = 3.1% oil, 40:1 = 2.5% oil, 50:1 = 2%oil. I'd say get some of those sliding vents that can be installed on the air box to increase flow. When it's hot run it w/o the air box lid. As it gets colder put the lid back on and open a vent or 2. When it gets like 40 or 50 degrees colder close all vents with lid on for maximum restriction of flow. Then as a last resort if it gets even colder go from 32:1 to 40:1 or 50:1 if your oil is designed to go that thin. Yeah, it would take a very drastic difference to change the air/fuel mixture of the bike equal to that of a minor jetting change. Not too mention, your flirting with the lubrication of your engine, and that is not something you want to screw with. If your having that much trouble, get a "Dial-a-Jet" and eliminate the need for minor changes. It will give you adjustment equivalent to +10 on the main to -10 on the main with just the turn of a knob. Lots of adjustability, and not very expensive at all. Check Rocky Mountain ATV. Quote Link to comment Share on other sites More sharing options...
MotulMonsta Posted March 6, 2004 Report Share Posted March 6, 2004 40 degrees won't make that HUGE of a diffrence on a good running motor. Quote Link to comment Share on other sites More sharing options...
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