95 tz250 AVGAS carb settings

[deano123]

Wondering if anyone can give me the base carb settings for a 95tz250 running neat avgas and also the recommended timing setting? As bike came setup for unleaded and converting it back to run avgas

Bike is bog stock with 96 cylinders only (put all leaded kit back on it)

[erock768]

I ran my 93 TZ on avgas as follows. Also of note this bike was Oliver's 93 AMA bike, and Ed Sorbo's after that. It had stuffed cases as carbs bored to 39mm.

Cylinders:
.2 mm Positive Deck height
.6 squish
7.6 cc heads

Carbs:
17 pilots
R6 Nozzle
4.0 slides
80 power jets
stock needle
Mains typically from 330-380

Ignition:
I ran a 1997 ignition (4DP-40)
standard timing is 1.7mm BTDC and I typically ran 1.7 -1.85

Should get you close. depending on ambient temp and elevation.

Eric

[Stealth]

Does avgas typically have a slower burn rate than a leaded race fuel hence an advanced timing setting?

[erock768]

The characteristics of avgas vs fuels of similar ilk (leaded, 100 octane) have been discussed at length on this site, anmd since I know very little on the topic I won't get into it. I am no expert on the chemistry/burn characteristics of 100LL as compared to other fuels. However, I have used VP c12 and 100LL avgas back to back and noticed no difference between the two. My empirical data is limited to: 1)seat of the pants. 2) close examination of plug burn back and piston color 3)back to back dyno runs with each fuel.

Based on my experience and skill level I save my money and go with avgas. You might want to ask Vince too as he runs it in his 5ke and he's faster than me so his opinion might carry more weight.

E

[vince24x]

well, to be faster, i'd need to actually be riding, but... lol

i use 100LL b/c:
1) it works fine
2) it is cheap
3) it lasts forever
4) it has a suuuper wide tuning range

i agree 100% w/ eric: it is very similar to VP C12 imo. just half the price.

hth,
vince