squish question

Bob

I didn't mean to go down the rabbit hole here on jetting, but since you asked. Last year I thought I had a carb problem. I spent alot of time chasing my tail. The machine was bogging hard at 3/4 throttle, then it would take off like a bat out of hell. Well I re-jetted about 4 times, and played with the needles. Re-jetted, plug tests, re-jetted, plug tests.,........ Turns out it was bogging because of the secondary clutch spring not having set to the proper tension. It had an aftermarket roller clutch mod, and it didn't work well. It would load it up to much. Put stock back on and it went away. The machine ran well after that. It seemed IMO to runn really well. Anyway I am intimate with the carbs, but like I said in the thread I thought I was getting good signs from the spark plugs. So here I am again at square on. The information. I will get the current carb settings, they are at home. The machine is a 2000m mountain max, redhead. So no powervalves It has been ported. It has SLP ceramic coated tripple pipes. The air box has been opened up top the Totally Yamaha tch pages air box mod. The lowest I ride is 10,000ft the top 13,000ft. The temperature is the rub -10 - 40 deg depending on the time of year. I am always ready to learn more. I appreciate all the input. :postwhore
 
some guys swear by an ATTAC system.It automatically adjusts for the temps of the day..maybe look into that as a possibilty instead of changing jetting to compensate.
 
maxco said:
It seemed IMO to runn really well. Anyway I am intimate with the carbs, but like I said in the thread I thought I was getting good signs from the spark plugs. :postwhore
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Well as the saying goes..."If it ain't broke...don't fix it"!
 
maxco said:
The only manual I see advertised is the clymer. Maybe I missed it. Can I download the PDF of the OEM manual somewhere? Thanks
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I see now that your application isn't what I thought (I referenced an '00 SRX manual for the 22-24mm cable spec). As Blue suggested, become a VIP and all the factory service info is available. Considering the cost of a hard copy from a dealer (if it's even still available), the cost of a VIP membership is well worth it.

Also, Don can give you better direction regarding the pistons your using and most here will recommend genuine Yamaha. Having said that Wiseco makes a good piston but they require different piston to bore clearances and longer warm up time which requires you to be the first out of the watering hole warming your sled/gearing up while your buds pick up the tab. Win-win!
 
Thanks

Ok looked at my log. Here is where it is set. Mag side to clutch, 137.5,137.5,138. Main jet 62.5, needle 6DGM5. air screw 2 1/2 turns out. needle at 3 one shim up one down. I need to get the machine up and running to be able to do some wash, and plug tests. But given the information where does this put me? Lean I guess, She idles well enough. I Just do not have a baseline with the Mods done.
MrViper said he would call me tonight. I re-assembled the engine like he said, and with 1 base gasket and a factory cylinder gasket, the piston would not turn (hits the head). This machine will run 2 base gaskets. Don said he will machine the heads to fit.
So where on the site does one go to upgrade to V.I.P.?
:2strokes:
 
Just for comparrison....Benders jetting recommendations for a ported, Bender piped 700SX is as follows:

7000ft and above
pilot jet = 50
fuel screw = 1.75
Main jet = 142.5[they only call for 132.5s when stock!]
Needle clip = 2

On our Bender Piped, ported, mod airbox, 700 SX at 1200 ft I run 152.5s [and have for 10+ years without issues]
that would convert to 142.5s at 8000+ for the same temps.

I believe SLP calls for 135 mains on a STOCK 700 at the altitudes you run so they are close to what Bender specs maybe a little richer.

With the above info you may be a tad lean at full throttle on a ported motor with the main jets you are using.

Better richer then leaner...

JM.02c

Bob
 
Hey I dont care what everyone else says you guys are allright

thanks, Bob and Blue. To respond to Blue. I have an AATTACC, I bought one with the machine. I read some post that scared me. Quite a few guys have burned down thier machines. Apparently you have to be religious about opening your hood every time you stop. If you do not open it, the ATTAC takes a reading on the temperature/density under the hood. If you sit the temps under the hood go way high giving a false reading. I am relaying second hand information here, but what I read made me cautious. I just don't want to mess it up.
 
Hey Bob

So I looked around the bender site. I didn't see a file I could look at for jetting. Did it come with parts you ordered? I would love to have a copy. I looked at my SLP Tripple pipe set up sheet. Now this is for non-ported moter. 9000-11000FT is calling for 60 mains, 127.5 jets at +20-40 deg. I would be very curious what Bender had to say. When you get up to as high as we ride you get alot less air, and jet down to compensate. I rode (on a friends machine) yesterday at 11,500ft. The parking lot is 10,000ft. I bet these machines howl at sea level. It seems most of what I do (pipes,porting) will just get me back all the H.P. that I loose due to altitude. LOL
 
The jetting sheet came with the SX tripple pipes when I purchased them in 2000 and they do only reference 7000' and above and the mikuni jetting calculator only compensates for up to 8000...at 11000' you are way up there where nobody rides!! So you are right...you can go leaner at 11000' then 7000'. As long as you are safe at the lowest altitude/temp you ride at.
 
That seems to be one of my problems. Most charting drop out before they get to my altitude. My SLP chart at least goes from 9000-11000, and gives a temperature swing in jets from -20to -40 all the way to +40-+60. Hard part is in a season I will go thru those temps. It was 50 deg yesterday. Early season we ride -20 when comming home in the dark. Those charts give no guide lines at all about porting. AKA go 2 jets higher if ported for same temps. So I have been testing, documenting, and feeling/hearing. I just picked up a Steelman bend a light I will do some piston wash observation when my machine is up and running. That will most likely be next season. :2strokes:
 
Have you called SLP they should be able to help. Also Tom Hartman would be someone I would also consider calling, nice guy and really helped me when I was setting my sled up.
 
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