jetting question

D

DARV

Life Member
Joined
May 11, 2003
Messages
255
Age
64
Location
fort frances, Ontario
i was reading turks tips i have just bought a 1998 sx700 he says that the jetting should be 142.5 do you do it all cylinder the same from the factory the pto is one size larger so should it be pto 143.5 and the others 142.5
thanks for the help.

jerry
 
jetting

on the stock jetting the pto is one size larger than the # 2 & #3 cyl
if you take turks jetting he say's to go to 142.5 and drop 2 layers of head gskt i want to know if the pto cyl should be one size larger so it would be
143.8 one the pto and 2 & 3 142.5
help please
Jerry
 
a lot of people run straight jetting, because they find that the temperature difference between the PTO and the other two cylinders is not that great, and that with the PTO being one size richer it seems to make it quite a bit richer than the other two. If it were me, i would probably run the PTO with the 143.8, and use the 142's in the other two, at least to test it out, and if the PTO is still really rich, then maybe jet it down to the 142 as well. Definately better to start rich and work down for obvious reasons, and its easy to change jets. I like to run my stuff on the safe side, so i keep it a little rich. Have you ever considered a tempaflow so you dont have to worry about this? I have one, and they are a great product
 
i ran my 97 700sx with 2 at 142.5 and 1 with 143.8 with no trouble since it was new, thin head gasket mod also and dropped the needle 1 clip also. i ran it in temps from +10 celcius to -40 degrees celsius with no issues!
 
WrdAl, i can't really compare with you because i have Simons triple pipes, but with the tempaflow, run your stock jetting and anytime the temperature is above -20 F, the tempaflow will automatically compensate, making your jetting spot on. The calibration is simple, fuel mileage will increase, and performance will be much better and A LOT more consistent, well worth the money.
 
Holic,

Thanks.

According to the factory jetting charts, the stock jetting (145, 143.8, 143.8 ) is only good to +20F at the lowest altitude we ride (sea level - 300), and 0F at 300-1700ft. I also usually run oxy-fuel so I needed to go richer. I ended up with 146.3 in all three which should be safe at -20F (0-300) or -40F (300-1700).

With the Tempaflow set 1/8 turn rich, the stock jetting looked REAL lean in #2 & #3. Haven't had a chance to ride/test yet, but I'm confident the new jetting will be safe.

Only got to ride once with the Tempaflow last year, got a hernia in January and was out the rest of the season recovering. Only got to ride 3 times last year. SUCKED!!!
 
i know all about that hernia garbage, i have had two of them, but both of them were upper gastric, so right by my belly button, not down low, thankfully. Sure puts a damper on strenuous activity though :o|
 
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