Originally Posted by Lonestar (Post 7859469)

Hurray!!! My N21R outputs the expected low and top-end performance, now it's shimmed at 0.7mm (for 25%). It's still a bit lower than I'd really wish on torque, but top rpm is in the upper quintile I'd say (086HS pipe). Initially I tried to make it work with a #6 Nova, but I just couldn't get it right, it would still overheat, then I went to Odo77 and suddenly it woke up and started being consistent. No flameouts, despite a slightly rich LSN to protect temps.

Now if I could only go past 8:30 runtime I'd feel even better ( I don't think the LSN can add more than say half a minute). If I have time I'll try to put the 9901+41030 back on it to see if runtime picks up.

Thanks all for the help - Sunday is raceday, nothing feels better than beating $450 mills with a $150 one, I'll let you know how it goes :nod:

Paul

Originally Posted by cordarrow (Post 7860153)

They work...but they're super hard. I've chipped more than one Hudy on tight head screws...it was a tuning tool, after all.

Can't beat a good fitting Crapsman for head screws...find one with the perfect blade thickness...then remove the girth for a perfect fit in your heads counter bore...

Originally Posted by cordarrow (Post 7860153)

They work...but they're super hard. I've chipped more than one Hudy on tight head screws...it was a tuning tool, after all.

Can't beat a good fitting Crapsman for head screws...find one with the perfect blade thickness...then remove the girth for a perfect fit in your heads counter bore...

Originally Posted by rotarynut (Post 7860666)

Monty, have a question, are the head screws on the FMS 3.5mm 0.6 x 18mm long? I want to put on some allen head screws, I'm not too fond of flat heads,know what I mean! I already replaced the ones on the back plate.
the FMS is running good, just under 1 gal thru it now, thanks man.

Originally Posted by houston (Post 7860180)

the crank is still a sport crank ;)

9901ss/41005 would be better in the buggy if you are going to use the 9901ss pipe . the 086hs pipe is awesome but does not promote great runtime , great power , a lil violent powerband and crazy top , works awesome on the n21r limited :nod:

Originally Posted by Lonestar (Post 7861412)

Fair enough, still a sport mill after all :D

I unfortunately don't have 41005... and i'm not planning to buy more bits to make this baby work :lol: I have a 41052 in my boxes though but I think that might promote top-end a bit too much (And a pallet of 41021 and 41030). I run an mbx-6, so not everything fits without physically touching the body/tank/sideskirts...

Are the 9901ss's internals different from the 9901's?

Thanks for all the info - I'll dedicate you my victory sunday :D

Paul

Originally Posted by houston (Post 7862426)

Pipes aren't necessarily different internally but they do perform different .

Originally Posted by houston (Post 7862426)

41052?
9901ss/41005 pipeset works on almost all novamills ;)

Originally Posted by houston (Post 7860172)

your carburetor is just out of balance and you should try to run the 41021 header on the truggy with that engine . everything else seems ok , odonnell 97t plug ;)

Originally Posted by Tricky (Post 7863455)

Thanks for the help! I ended up changing the plug (97t) and richening up the bottom end quite a bit and it ran fine..no more flat mid range. I'll swap the 41005 with a 41021 that I have on by buggy. So the 9901/41005 will be a good combo in a buggy?

Thanks again!

Originally Posted by Lonestar (Post 7862493)

really??? same geometry, working differently? Materials vibrate differently to acoustic waves, maybe?

thickness of the wall on an exhaust plays a large part of the way it works yes, the new pipe is probably a touch less volume but it definitely runs better handsdown

41052 isn't a nova ref, sorry - it's a JP Racing (not Jammin Product) rebadgeing of an original nova pipe whose ref I can't find - here's a pic:

http://i.ebayimg.com/10/!Br8emi!CGk~...rQN(w~~_35.GIF

tried that style of header before and for some reason it just never felt right , just felt wrong ;)

I bought it last year like a week before nova released the 41030 as I didn't want to melt a second tank with the "stock" 41021 :ha:

41005 - the one with both 90deg angles??? :weird: that header works killer on the buggy with the 9901ss :nod:

thanks for all the help :blush:

Paul

Originally Posted by houston (Post 7861133)

why do you feel that you need to disassemble the engine ;) thats my first question , tonys screwz is the screw company that offers replacements i believe . i am pretty sure they are 3.5mm but for some reason i am thinking they 3.75mm

i have had a hudy driver for the heads and have torqued and untorqued 1,000's and 1,000's of those flat head screws with no issues ;)

Originally Posted by rotarynut (Post 7864455)

Monty, it's just a personal thing against flat heads, I'm an auto tech and disassembly and reassembly is in my blood :lol: I'm doing it mostly for inspection purposes. my calipers measured the screws at
3.4 and change so 3.5 has to be it. yeap I just checked @ tony's screws
3.5mm , the kit to do the complete engine is $5.