#7 slide

[fremontguy]

Just got me a #7 slide to help with jetting, plug fouling woes. I couldn't see any difference in size, by looks with #6. Will this slide change be equivelent to smaller pilot, bigger needle combo? I installed with 40 pilot, n85e top clip, 175 main for 4000'. My next step will be to buy a handfull of single taper needles, this jetting is a vicious circle.

 

[Strick]

Single taper needles are a must. 1367_, 1368_, 1369_

 

[fremontguy]

Yes Strick, I think I have run out of jetting options if this new slide doesn't cut it. I will shop my local dealers for the 13N series needles or Carb wherehouse, so I'm prepared in high altitudes.

 

[KTM Mike]

Fremontguy,

I just redid the jetting on my 97 300exc - had major problem just off idle. Ended up with #7 slide, 175main, 40 pilot, went to a straight taper needle, 1369 (cgk) , clip in #3 or 4 from top (forget which) air screw at 1 1/2 turns out. It is absolutely no spooge, crispe and clean, plug reads great - I may try a 42 pilot, as it seems a touch lean down low. I am at oh 500 to 1000 feet in elevation.

When i looked at my stock #6 it did not look any different to the naked eye from the #7 either. regardless - the #7 and the needel change worked out great. My next step will be to try mix of race gas and pump gas just for grins and giggles.

BTW - (not sure if i can say this here or not - sorry if Im not supposed to ...) there is a ton of great jetting info on holeshotktm.com's web site - take a look - Strick even offers up some great advice there once in a while, and James Dean is absolutely Mr. Jetting - he knows his stuff IMHO)

 

[Strick]

Back to the slide, I overlooked it before. If you look at the bottom of the slide you will see a #6 stamped on the original, and a #7 stamped on the new one. The differnce is very slight to the naked eye. We are talking about a 1mm (1/25 of an inch)difference in the cutaway area only.

I do think you will like the smooth throttle response you should experience with the single taper needles. Let us know how it all works out for you.

And yes KTM Mike, we are all thankful for James Dean (the jetting Guru). I will be especially thankful, if I ever decide to get a 4-stroke (in addition to the 300).

 

[fremontguy]

I tested #7 slide yesterday 95deg. @ 4000' w/ 40P, 175M, N85E#1. This was too lean on bottom, middle and too rich on top (I thinks), fouled plug on uphill after 2hrs riding, also was over heating. Changed jetting to 38P, N85E#2, 170M -better middle but sputters 1/4 throttle. Anyway I ordered CEK, CGH, & CGJ, where should I start with new needles and jetting??

 

[dirt bike dave]

If it was too lean on the bottom and middle with the #40 pilot, perhaps you should have tried a 42 instead of the 38. I'd make one change at a time and leave the other stuff as is and go with a #42 pilot for starters. JMHO.

Best of luck getting it sorted out!

 

[Strick]

I would take Dave's advice, bump that pilot back up to 42. AND, do everything one step at a time, so you know which step is influencing the change. You'll get 'er dialed!

 

[fremontguy]

Thanks for advise guys. With needle on clip#2 it's really oozing spooge, I wen't down to 38P to prevent plug foul, but I will try the other direction 42. My 300exc hasn't been the same since topend rebuild. Now I have working powervalves, non-chipped Boyseen reeds and good compression.