HEADS UP!!!

Site upgrade in progress... Core site functions are working, but some non-critical features/functions will be temporarily unavailable while we work to restore them over the next couple of weeks.

Please post any bugs you encounter, but before you do, check to see if it's already listed.

Thanks for your patience while we work to improve the community.

Sign in to follow this  
Followers 0
SNO-PRO

2010 450 Cold Weather

35 posts in this topic

Anyone else riding a new 450 in cold weather? I ice ride and generally ride between 0 deg F to 35 deg F. I have been seing a fair amount of fuel dilution in my oil, I have not sent it in for anaylsis but you can smell it and its actually changing the color of the oil to light brown. About 15-20 deg F and lower seems to be more of a problem area. My dealer called Yamaha and had no luck in any kind of setup advice and it basically sounds like I am the guinea pig. I have been backing off the fuel with my tuner but its really not making a big difference. I Change the oil after every ride in my attempt to see if tuner settings are making any noticable difference and to hopefully help the life. Obviously I am very concerned about the long term effects.

Share this post


Link to post
Share on other sites

some of the 09 crf's were seeing fuel in the oil...NOT a good thing...someone had mentioned bad injectors you may wanna look into that.

Share this post


Link to post
Share on other sites

It starts awesome pull the cold start knob and 3-4 kicks and its purring away. I love not having to figure out if I have to pump the throttle more or less like my carbuerated yz's

Share this post


Link to post
Share on other sites
It starts awesome pull the cold start knob and 3-4 kicks and its purring away. I love not having to figure out if I have to pump the throttle more or less like my carbuerated yz's
And that endearing behavior is brought to you by a sloshing abundance of excess of gasoline. That's the only way to get an engine to run that well at such low temps, and the programmer simply has to dial it into the firmware for the system to know that. To make matters worse, EFI systems self compensate for temperature the whole time they are running, not just while the cold start knob is pulled, and while this results in a much better running engine while it's cold, the down side can be more fuel in the oil unless the engine is run to full operating temps and kept there for 15 minutes or so. (Full operating temperature means the oil has reached 160 degrees)

If the bike gets ridden for a while, the oil should purge itself of the fuel without any problems.

Share this post


Link to post
Share on other sites

Would progressively taping (blocking) off the radiators (until you find a happy medium) to get the engine to run hotter help?

Share this post


Link to post
Share on other sites

Somewhat like the over-the-road tractors you see with the zip-up covers on the grille? Possibly. So would a thermostat, but that's not as simple as it sounds.

Share this post


Link to post
Share on other sites
Somewhat like the over-the-road tractors you see with the zip-up covers on the grille? Possibly. So would a thermostat, but that's not as simple as it sounds.

Yeah, but I was thinking more NASCAR where they sometimes peel off/add a strip of tape to the grill to adjust the operating temp of the motor (or alter the aerodynamics).

Share this post


Link to post
Share on other sites

Hmm interesting point as another rider runs a fuel injected RMZ and the radiators have to be completly taped up for it to run decent. If not that bike will pop and spit and sputter wildly.

Thanks for the advice Grayracer I will try getting more heat in the bike by blocking radiators off. Do you know what a normal water operating tempature is intended to be and is there a correlation to oil temp? With my programer I can monitor water temp thus I could see how much blockage may be needed if its a direct correlation

Share this post


Link to post
Share on other sites

It would be nice to see a warmed up engine running at least as hot as 160, and of course, assuming 50/50 EG coolant at 16 psi, something less than 250.

Oil is heated by the same energy as the coolant is, and does not have the same means of being cooled. Oil temps tend to run higher than coolant, but there are a lot of variables, and no really direct correlation.

Share this post


Link to post
Share on other sites

Thank You Grayracer

I found this weekend riding it with a ambient tempature of 20-25 that I saw a water tempature of 100-110 degrees. Through many trials i found taping my radiators off to 100% blockage gave me a water tempature of 175-185. And with the engine running to tempature my fuel in the oil problem was no longer.

Share this post


Link to post
Share on other sites

I rode this weekend for the first time and I must say I am very impressed! I will write up a review later but I can say it started every time with one or two kicks! It was 34 degrees F

Share this post


Link to post
Share on other sites
Thank You Grayracer

I found this weekend riding it with a ambient tempature of 20-25 that I saw a water tempature of 100-110 degrees. Through many trials i found taping my radiators off to 100% blockage gave me a water tempature of 175-185. And with the engine running to tempature my fuel in the oil problem was no longer.

That's good info, thanks for the feedback.:banghead:

Share this post


Link to post
Share on other sites

That is interesting...I wonder how this info would correlate to the older YZ450F's. I've been contemplating on taking my 05 out on the ice and now wonder if I should block off my radiators. Is there an accurate way to get coolant temps from a carbureted bike?

Share this post


Link to post
Share on other sites
EFI systems self compensate for temperature the whole time they are running, not just while the cold start knob is pulled, and while this results in a much better running engine while it's cold, the down side can be more fuel in the oil unless the engine is run to full operating temps and kept there for 15 minutes or so. (Full operating temperature means the oil has reached 160 degrees)

If the bike gets ridden for a while, the oil should purge itself of the fuel without any problems.

2 questions - Can you help me understand how exactly the fuel would get into the oil when the EFI is compensating for the cold weather? Also, how would the oil purge itself of the fuel if you ride it for a while?

Share this post


Link to post
Share on other sites
Is there an accurate way to get coolant temps from a carbureted bike?
An enduro computer like the "Vapor". Next best is the thermometer tapes form Pro Circuit and others. Apply it to the top tank of the radiator at the point where the upper hose enters.
2 questions - Can you help me understand how exactly the fuel would get into the oil when the EFI is compensating for the cold weather? Also, how would the oil purge itself of the fuel if you ride it for a while?
Cold engine operation requires richer than normal mixture. Very cold engine operation requires much richer than normal mixture. With a carb, you have only two modes of operation:cold start, and normal. Ordinarily, you use the choke to start the bike, but you switch it off as soon as possible, which moves you to whatever your hot engine jetting is, even if it's a little lean for the weather.

EFI doesn't do that. Once you switch out of the cold start mode, it "rejets" itself for the temperature, base on ambient air and coolant temps, and will be running quite a lot richer in freezing weather than a carb jetted for the 50's or 60's.

Any engine will push fuel into the oil on a cold start. The amount of fuel that would remain in the oil in a cold started engine that was shut down in two to five minutes would amaze you. If you doubt that, send in a used oil sample after doing that sometime and see what the results say. Under normal conditions, the fuel simply evaporates out of the oil and leaves via the breather tube. The few elements of gasoline that are not volatile enough to evaporate at 150-160 degrees are absorbed by the detergent package.

The trouble here appears to stem from the fact that the bike has no thermostat, which causes the coolant to be over-cooled, and the EFI is responding as programmed to the low coolant temperature, thinking that the engine is in it's warm up phase. This allows it to deliver a mixture rich enough to push fuel past the rings, even while "warmed up".

Note that SNO-PRO reports no more oil in the fuel after blocking the air to the radiators.

Share this post


Link to post
Share on other sites

as it gets hotter outside, it would be interesting to learn at what ambient temp the bike begins to run correctly with the radiators completely uncovered so as to determine the trigger temp for beginning to cover them up when it gets colder. i dont ride MX in sub freezing temps but I do often ride between 32 and 50 and I am sure that at those temps, the bike is not reaching optimum running temp for this to be alleviated.

Share this post


Link to post
Share on other sites

I'm going to guess the coolant temps should be in at least the 140-160 ℉ range for the ECU to call it warmed up.

Share this post


Link to post
Share on other sites
I'm going to guess the coolant temps should be in at least the 140-160 ℉ range for the ECU to call it warmed up.

So approx what ambient temp and normal use would yield a "warmed up" coolant temp with no tape on the rads? I guess thats my question?

Share this post


Link to post
Share on other sites

No idea. You'd need to experiment with that. It will also depend to a great degree on exactly what you're doing with the bike.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now
Sign in to follow this  
Followers 0