Kayaker, higher octane fuel will not help cold starts. it will start better with the lowest octane the engine will tolerate (not detonate). the difference is small but octane raises the autoignition temperature of the fuel. auto ignition temp is the temp that will ignite/ start the burn of the fuel. the reason starting fluid works is because it has a lower autoignition temp than gasoline or diesel. diesel starts from the heat of compression because the auto ingition temp of diesel is lower than gasoline. gasoline needs the heat of the spark to ignite the fuel. I also would not be afraid of a small amount of starter fluid. the problem with starting fluid is it lowers the autoignition temp and can result in detonation which is not good for the engine. but, it starts the burn/combustion process at a much lower temp. as I mentioned earlier, higher voltage at the coil when towing can increase the voltage of the spark at the spark plug. higher voltage means higher temp which increases the chance that the gasoline will ignite. another option is park it on a hill and push ride it downhill in a gear that will spin the engine.
ECU mappings
- Thread starter thewwkayaker
- Start date
I thought of that when I posted that - about lower vs higher octane. I was just thinking about the lower water content in higher octane (less ethanol which is hydroscopic) but you are correct about lower octane being better to start (but hard on an engine designed for higher octane for higher compression). I"m probably going way overboard in my concern for cold starts but I figure if I chase down all possible ways to help then if or when I find myself in that situation I'll have a bag of tricks that hopefully will give me a solution. Thanx to all for your ideas!
Shoot me a text. 801-949-8936. I’m sure I can round it up (might be buried under a few things). Little busy with work and Christmas and family, but I could probably get it sent out in a day or two.
Obviously, you’re not the only one who struggles with this. Let us know your results if you have some cold temperatures and maybe we can all learn from it. Good luck!
Kayaker, actually ethanol has a higher octane rating than regular gasoline and is added to bring regular 87 octane to the mid or premium level. in our state it is limited to ten percent in any blend. but there is good chance that you would get more water absorbing ethanol in a premium blend. if you are going to burn the fuel within a few weeks, I prefer a little ethanol because it is a good gas line antifreeze. ice in the fuel is a bad deal.
Yes I see that now - I thought engine starting fluid was made from that but I'm clearly wrong. Always fun to learn new stuff though.
This tuning allows for increased horsepower, better fuel efficiency, or improved throttle response, depending on the driver’s goals. ECU remapping can be customized for different driving conditions, whether for high-performance racing or everyday fuel economy.
We shipped back all the PR2 ecu for the 450 KTM,s, the 500 ECU worked ok but the 450 ran better with stock ECU and pulled higher RPM,s , The C3 Vortex mountain Map has been the strongest ECU we have run on a stock 450 engine , The 470 BB,s run best on the standard C3 Vortex mapping. Raze ECU lost RPM and HP.
Funny you should mention the velocity stack. When I installed mine is when the cold start issues began. I'm riding a 17 Honda CRF450RX. I have the C3 vortex ecu and have the low mixture adjustment turned up fully to try to compensate, but still does not start like it used to before the velocity stack.
Hmm the low setting effects only while throttle closed to just partially open, The air is grosly restricted , The intake chosen has no effect on fueling at that throttle position.. Intakes are designed to flow more air and increase volicity at full throttle when throttle body is wide open which increases the engines running compression as well ,That is where extra fueling my be needed to keep proper fuel to air ratio.
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