300 Xc, gore porting and Sx head set at .060 sqwish, Sx box, new smart carb with avids heater. Wide open pulls in wet heavy snow I saw temps pushing 1250 and climbing before backing off. I saw this on my gas gas cast smartie also last year. What are others seeing as I know there are more 300's out there this year....thank Garry
Smart carb egt's
- Thread starter the gman
- Start date
1190 to 1230 for a long full throttle pull according to the ultimate 300 build thread.
Aluminum melts at 1221 F
not sure if you saw this:
http://www.snowest.com/forum/showthread.php?p=3735909#post3735909
post 32 and 34
what kind of egt did u get? I need to get one
http://www.snowest.com/forum/showthread.php?p=3735909#post3735909
post 32 and 34
what kind of egt did u get? I need to get one
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My egt's were 9-1000 putting around but would climb fast in the wet heavy snow breaking trail. Had a little flat spot three quarter to wide open and am told the 78 should help cure that. Wide open showed 1200 up to 1270 when I would back out because I don't like walking..... I also had a bad pinging at three quarters throttle under heavy load which I figured was detonation.
Sorry which bike is this ?
What fuel are you feeding it? I find my 300 with almost the same set up really likes the 98 octane range of fuel.. I mix up with 110 and pump… I ride 4000 and up.. Maybe even try 100 and lower through testing you do not want detonation… as you most likley know…
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M
mtn-doo
Well-known member
Hey Gary,
Yes, the .080 rod comes stock. It is spot on for most bikes. Super clean and lean. 1250 to 1270 is optimum for most applications but with the long WOT use we see on the snow, I would prefer a tad bit richer. The .078 rod is the next richer rod. Each rod size equates to approximately 200F. 1050F would be a bit rich, but safe. The engines are all unique and individual. I would try each rod and shoot for high 11's to low 12's as ideal for our WOT use. If you are running an AFR you want 14.5 to 14.7 at idle and mid to high 12's at WOT, not over 12.9.
Yes, the .080 rod comes stock. It is spot on for most bikes. Super clean and lean. 1250 to 1270 is optimum for most applications but with the long WOT use we see on the snow, I would prefer a tad bit richer. The .078 rod is the next richer rod. Each rod size equates to approximately 200F. 1050F would be a bit rich, but safe. The engines are all unique and individual. I would try each rod and shoot for high 11's to low 12's as ideal for our WOT use. If you are running an AFR you want 14.5 to 14.7 at idle and mid to high 12's at WOT, not over 12.9.
For the ride Friday it was set at 79 from full rich. Tried three more rich but bike didn't run well there. Yesterday I set it up like I was taught...leaned it until it bogged wicking the throttle and then just rich from there...good fast responce and motor sounded like it hits on every stroke, never heard that other than with these carbs. Went over this am to see where I ended up and wtf...I am at 89. Granted I have not rode it this way but this seems lean from what others have run. What's your take on this summit...you have fiddled with this carb more than I. THANKS
Well i was under the impression the deto lean spot at 3/4 throttle was more of a 500 issue. I found the same sort of setting worked well on the 500 as long as i used some race fuel or fuel builder. If not i would get deto (which sounds like a can of marbles) at roughly 3/4 throttle under load and a little on decel.
My guess is if you go to the 78 needle and u adjust it will be in the 100 click range to make it run nice and crisp. Ur deto may go away on the 78. Its kinda a balancing act with the Smarty needles. I found the 78 wasn't too bad but it didn't run as well as the 80 and had poorer performance as far as midrange throttle, idle and starting were affected. The 76 for me was way to rich.
Call Corey and discuss. Maybe they have a slightly different needle for the 300. I don't run a AFR or EGT so take this for what its worth. I just go by my tuning ear LOL.
Curious how the 300 guys are finding cold starts or initial starts with the Smartcarb ???
My guess is if you go to the 78 needle and u adjust it will be in the 100 click range to make it run nice and crisp. Ur deto may go away on the 78. Its kinda a balancing act with the Smarty needles. I found the 78 wasn't too bad but it didn't run as well as the 80 and had poorer performance as far as midrange throttle, idle and starting were affected. The 76 for me was way to rich.
Call Corey and discuss. Maybe they have a slightly different needle for the 300. I don't run a AFR or EGT so take this for what its worth. I just go by my tuning ear LOL.
Curious how the 300 guys are finding cold starts or initial starts with the Smartcarb ???
gman earlier I meant which egt did u get, koso rapid response? I ordered one today, any install tips? I have no experience with these things, how accurate are they? I assume just a tuning aid, if you rely on it you will burn down before you blink an eye, I use my tuning ear primaarily, lol. any tips or other info? I have read the ultimate 300 thread any info you could give above that would be appreciated! Thanks in advance.
Talked to Corey today and am trying a 78 needle.in the 300 I am going to leave the 80 in my 500 for now. As far as the starting both two smokers have primers. Cold morning starts I think they are a must. Pull choke, turn fuel on, two shots, with throttle wide open, slow kick to feed the beast and starts first fast kick. I have the nozzle on the filter side on top and LOVE it. Both bikes are the same...both are running koso fast probes set at 6 inches out from the piston skirt. Also was told 1290 was ok just not higher....I moved my flashing from 1200 to 1270 but I think 1290 is imo to f-ing high. Will let you know where it settles out next ride.
Chris I'll have to try this technique on the 500 in my cold garage when I get home in January. If it works it beats tipping the bike on its side to get fuel in that big cylinder lol. I though we both unsuccessfully tried this on the 500's if I remember correctly.
Patrick
I know for a fact the Smarty choke circuit is not big enough to start the mighty 500 in the cold. I tried the tip over technique. What i found is if i tipped it over 3-4 times and cycled the kicker 3-5 times per tip over. It would usually start fairly quick. I think the choke circuit could be opened up a lot more on the Smarty.
I have a pulse right now and it starts more or less 1-3 kicks with just the choke and cycle the kicker 3 times. My PWK has the choke circuit bored lol. Its a easier start for sure. The air doesnt stall across the venturi like a regular carb does.
I think the primer will help the 2 strokes in the cold for sure. Some guys at lower elevation seem to have a easier time starting the 500 compared to the guys at higher altitude.
I have a pulse right now and it starts more or less 1-3 kicks with just the choke and cycle the kicker 3 times. My PWK has the choke circuit bored lol. Its a easier start for sure. The air doesnt stall across the venturi like a regular carb does.
I think the primer will help the 2 strokes in the cold for sure. Some guys at lower elevation seem to have a easier time starting the 500 compared to the guys at higher altitude.
anybody got a 78 also known as a q09 rod they would part with? I called to order one on monday and was told 2-3 weeks. I'm assuming after Christmas from the sounds of it. I tried mtn-doo but he does not have one either. Its not really a big deal since the weather stinks here it just sucks the only method of truly richening the smartcarb is out of stock till Christmas or after.
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.078 metering rod
I sent the .078 back in for an .080.
Ask Tom if you can have it, it has 3 hrs on it, perfect condition.
Tom Heck
Technical Support
(816) 416-7145
(877) 372-3465
tom.heck@powerapt.com
I sent the .078 back in for an .080.
Ask Tom if you can have it, it has 3 hrs on it, perfect condition.
Tom Heck
Technical Support
(816) 416-7145
(877) 372-3465
tom.heck@powerapt.com
