I recently installed an AEM EUGO wideband air fuel sensor a couple days ago. I have installed an HMF straight through exhaust since then. i kept the stock airbox and snorkel to keep the power band in the upper RPMS. i have stock jetting and it is absolutely PERFECT. I dont see a need for a jet kit even on a stock bike. It runs 12-13 AFR WOT and 14-15 cruising. Which is perfect. The only thing i see on these bikes is the idle. I have the stock slow idle jet at the stock 1 7/8 turn, and its pig rich. runs 13 and loads up to 12. I have NO idea why jetting companies suggest 3 turns. If you'll look at my other posts I plan on building and offering an ignition system.

Ill post pics fairly soon.

 

heh, cool, I just bought that same unit but for my Eclipse GSX I found out that I'm running pig rich under 15psi of boost. The gauge bottoms out at 10:1.

Gotta get a fuel computer and lean it out a bit to squeeze some ponies out of hiding!

 

In the past, every time I have disputed the statement that these (all) bikes run lean from the factory, i have been ridiculed. There is no advantage, whether it's performance, or emissions, for the factory to set it up lean.

 

That's a very nice baseline data point! I never checked my bike in stock trim (bought it usde so I never HAD it in stock trim) but I was always curious about the jetting.

The cool thing is that I now have my TM36 jetted at those same exact numbers, around 14 - 15 at low throttle cruise and 12 -13 at WOT.
That's where the bike works best.

A huge variable in all this is the air box. As soon as you pull the snorkel, and even more so if you pull the complete lid, you will have to re-jet.
Not because engine gets any measurable amount more air but because the vacuum at carb venturi gets little weaker. The weaker vacuum pulls less gas through the main jet. -> Requires a bigger jet to pull same amount of fuel as before.

I'll shut up now.

--
Mikko

 

Oh yeah definitely, i built intakes (sorta), with what i have read on here and measured, the stock intake is the best design for the bike. i have another set of dimensions for the 351, but the head porting isnt really setup for the 351 for higher RPMs. So im going astray and staying with the 250 and doing an ignition, maybe cams. i really like the security of having a meter on the bike, especially for long trips not worrying about breaking down 200 miles from home.

 

i have worked on a couple for those, very fast and cheap and easy. Sounds like a friday night eh? No really. My friend ith "unlimited money" was running 28 psi, with the bet ARP studs and still stripped the head off the block. FAST

 

I've been saying this for a while that if you only add a simple slip-on you aren't really leaning these things out to any degree. For kicks and giggles put a free flowing AC and pull your lid and watch it go lean, as with my experience on other bikes has always been the intake made alot more difference than the exhaust alone on the afr.

 

I also have a uni in it. I just dont want to pull the lid, it has no top end if ya do. Ive done all that already.