Proper warm up procedure

R

robmc

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I was looking thru the posts here and noticed a lot of Yami owners like myself are having trouble with fouling out plugs on startup. I have an 02 sx600r which I got last year and at the beginning of the season last year I kept fouling plugs on startup but never fouled one after I had been riding the sled. After a couple of weeks I finally got the hang of it and I ran the same set of plugs for the rest of the season with no problems. Now this year I have taken the sled out twice and fouled the plugs both times. My procedure is full choke on start then immediately to the middle position for 5 or 6 seconds then choke off and I don't touch the throttle. I then let it warm up for a few minutes and go and if I am able to get on it right away it always clears out and I'm set for the day, however occasionaly I don't have an open path to clear it out. My sled is stock and is not using excess oil or gas. I know it is a startup problem because after I foul the first set of plugs on startup I then put a second set in and the sled fires up perfect and runs without a hiccup for the rest of the day.
 

I would like to see some input on this one too, since I know what you mean by a clear area, after warm-up/ ideling for a bit..... Sled just seems to load up with fuel when warming up / ideling.....

Once that excess fuell is cleared, the things runs perfectly.....

02 MM700

TJ500
 
your start up procedure is correct,the reason thease models take time to warm up is they have no thermostat they are cold hearted beast's
 
it is all in the warm up...use choke sparingly

i only use the chocke enough to keep it running untill it will idle by itself. i had trouble with my srx warming up too. now i let it idle for at least 5-10 minutes before i get on it. it will never foul if you let it get warm up really good.
 
These Yamahas need time to warm up.
I think your starting proceedure is ok.
Leave it warm up about 6 to 10 min before you ride.
I had the same problem but now I let it idle longer and no fouled plugs.
 
Warm the beast with care

I can relate to this one to, I was up in East Jordan over the weekend with -15degree's overnight lows. When I went to start it in the mourn she just did not want to go anywhere, backfire out the exhaust separating the exhaust pipe. I tried to free the track as best as possible- and believe me I'll prop the track off the ground next time when it get's that cold again. :!:
 
Thanks for the replies. I think my problem is not letting my sled warm up enough, for some reason I get it in my head that if I let it idle too long it will foul out. I had it down perfect last year but now I'm starting all over again this year! I bought a box of plugs today so I'm all set to try again. I'll let her idle for a good five minutes then try her out.
 
I don't know why but I'm still not convinced letting it idle/ warm longer will be the solution.... My 02 MM just loads up even further with fuel if it idles longer, and then when is time to go it barely can generate enough power to move itself....

I am not that savy with the different circuits of the carbs yet, but is it the fuel screws that control the idle?......Perhaps 1 and 1/2 turns is too much??? Any one else have some input?....


My plugs never foul out permanently....It only seems like it at the time because it is flooding with fuel...(I think).... (The plugs are fine once I go for a bit to clear the feul)....


TJ
 
TJ when I had this problem last year a lot of people told me I should adjust my carbs. I asked the mechanic were I bought my sled and he said not to and like I said in my first post after I got used to the sled I ran the rest of the season (jan-april) without fouling a plug. If I had adjusted the carbs it wouldn't of solved the problems. This may not apply to your sled as I dont know how it is set up but you may want to take it into consideration. Adjusting carbs can create diffrent results for diffrent temperatures.
 
ive noticed on my 03 sx600r that it likes to not be on full choke for too long how i warm it up is i start it full choke till she responds a little then immediatly flick the choke off and let her idle and warm up till i get a good throttle response then go and clean her out run her a little and hit the trails i havent fouled a plug yet though she is new
 
My 600srx will foul plugs every single time I start it cold if i give it any throttle before it is warmed up. I have to just blip the choke to keep it running when the rev's get down too far. Once it is warm, and starts idling smoothly with no choke, it is ready to go.
 
My problem was with me blipping the throttle while it was warming up. I put in a new set of plugs Thurs. and I've taken it out three times since then and have not fouled a plug. I previously had blipped the throttle on warmup to bring the idle up which like I said caused the problem but if your idle is low putting the choke back in the no.2 position briefly is the way to do it. I'm still loving this sled!
 
proper warm up procedure

:?: i to have the same problem
i have a 2001 600 SXR when i first go to start it backfires
througgh the muffler . also even when its warmed up enough
i seem to have a bog at low speed but at wot no bog any ideas
 
The only way mine will start and not foul is to have the choke on full till it starts immediately move it to half for about fifteen seconds or so,then I ever so slightly crack the throttle(3500rpm)until it smooths out which takes probably another 30-45 seconds. Then it idles fine. I do let it warm up fully before riding. Soc
 
One key point here is that what people call the choke is actually a starter circuit that does not restrict intake air as a choke would, but opens an additional fuel circuit that richens the mixture. On a cold sled this helps get it started, but as soon as it is running it can easily supply too rich of a mixture which can wet foul plugs. Wet fouled plugs should work fine again once they dry out, unless while fouled they alter the conductance and/or insulation properties of the plug.

I recommend that you first make sure the carbs are clean (all circuits), and that the oil mixture is adjusted properly. Be sure the cable end at the adjustment point is back in place. Also be sure that there are no air leaks in the intake tract. Then adjust the idle so that the mixture is good (and safe) with the engine warmed up (after riding) and the air temp and density at normal riding conditions. If all this is done, and the procedure outlined above is followed, then the sled should start and warm up without fouling plugs. If you do need to touch the throttle, say you need to move the sled right away, it will need more fuel to keep from going too lean and possibly dry fouling the plugs (Bad). Usually flipping the starter to the halfway position for a second or two every few seconds accomplishes this. Listen to the motor and you can tell if it is lean or rich.
 
I had the same problem on my 00 SRX. I used to foul plugs when I first got the sled and I haven't had a problem in a while. When first starting sled go to full choke. Once it fires go down to half choke for like 3 seconds and then take the choke off. I play with half choke and no choke for about a minute or two until it idles good. i used to leave half choke on a while and it fouled. Hope this helps
 
No fouled plugs in 4000 miles on '02 SRX.

The above posts for starting are similar and mostly correct, but once the cold engine is started with full choke, I would skip taking it to half choke. Take it all the way to the closed position and blip it to half choke from there. Don't even stay in the half position; simply flip it from closed to half and back to closed. This procedure may take about a minute of your time, but I'll guarantee you'll never foul a plug.

By going immediately to half choke for 5 or so seconds, you're assuming the sled needs that much choke. Go with what Ding said and listen to your machine. Only give it the choke it needs, and with experience on these sleds, it really only needs a quick "blip" and nothing longer.

As far as the backfire, be sure to let the machine idle completely down to it's normal idle (usually around 1500 rpm) prior to shutting the machine off. My wife's 700 used to backfire on every start up on the trail. She would ride up where everyone was shut down and resting and turn her machine off as soon as she was stopped. Next start - boom! We finally figured out it took approximately 30 seconds for the 700 motor to idle down to its normal idle range. Shutting down prior to this will leave unburned gas in the combustion chamber for the next start. Most folks we ride will will look at my wife giving her the "cut off the neck symbol", but we always tell them that it takes a while before she can bring silence to the moment.

Hope this helps,
Jon
 
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