Tricks and parts for more torque/bottom on a 250 RR

[Phatpat]

PhatPat, one for u to drool over, KYB Forks and Shock.

Nice one but I'm quite fond of my red Marzocchis, can't complain about the sachs shock either really but have yet to experience a better shock to compare with.

How much for the PV spacer incl shipping to Sweden? Spent loads already for this upcoming race so I really shouldn't but it sure is tempting.

[Gibnut]

Fit an S3 head, put in the red insert (I ride SL-700m ASL, 12c-34c), NEDW #2, 38p, 168m, a/s 1.5, Motorex full syn/98ron @ 2%, 13/50 gearing.

Very usable extra grunt down low.

[T.Read]

I have a 50T rear sprocket on mine now and I really like the change. Not as much for the extra grunt, but the range it lets me use on trails. I can run the tight trails around here in 3rd and keep it at relatively low revs, helps keep the momentum going. Keeps the traction up and doesn't feel like it's screaming without doing anything. I can take steep hills in 2nd most of the time without issue. I'm about 165lbs too.

[typeone]

i'm trying a 50T rear, X-Trainer PV spacer and Slavens Mule head this season... have a feeling i'm gonna dig the extra grunt

[Gibnut]

I fitted an X-Trainer pv spacer, too. $11.83AUD & 3 minute job. Noticeable increase off-idle. Not omg, but it's there alright.

I rode my brother's Sherco SE-R 300 a couple of weeks back and apart from the fork being plusher (WP oc, fantastic), I had zero envy of the extra 44 cc.

[Gibnut]

I fitted the black insert (hi-hi-comp) into my S3 Stars head 2 weeks ago & have ridden twice (once with 12/48 gearing, too - using up a near new Beta Supersprox rear cog & chain..).

Jetting is unchanged - NEDW #2, 38p/168m, a/s 1.5, Penrite MC2ST 2% in 98ron Australian pump fuel, SL-900m ASL, 2c - 32c. Squish is 1.38mm. I can't measure compression as my gauge won't fit under the frame.

The result, particularly with 12/48, is great. You find yourself looking for 7th above 80km/h, but in s/t it is such a great set up for me. I bloody love it.

Beefier pull right off idle & quicker throttle response means even more flow between the trees = 2nd & 3rd gear single track joy.

I now start the bike with the kick start first thing (it's cold here early doors) but the noticeable extra compression doesn't affect the e-start at all when the bike is warm.

I keep looking for reasons to put a 300 kit on at 100hrs, but the 250 motor keeps giving me none.

It'll get up any hill my mates on their 300's (+ my brother on an RR480) can.

What a motor!

[typeone]

I fitted an X-Trainer pv spacer, too. $11.83AUD & 3 minute job. Noticeable increase off-idle. Not omg, but it's there alright.

I rode my brother's Sherco SE-R 300 a couple of weeks back and apart from the fork being plusher (WP oc, fantastic), I had zero envy of the extra 44 cc.

did you notice an increase in pipe bang on decel with the throttle closed after installing the PV spacer? i'm trying to chase down what's causing this on my 250. removing the spacer will be a quick easy test to see if it's related.

[Gibnut]

I fitted an X-Trainer pv spacer, too. $11.83AUD & 3 minute job. Noticeable increase off-idle. Not omg, but it's there alright.

I rode my brother's Sherco SE-R 300 a couple of weeks back and apart from the fork being plusher (WP oc, fantastic), I had zero envy of the extra 44 cc.

did you notice an increase in pipe bang on decel with the throttle closed after installing the PV spacer? i'm trying to chase down what's causing this on my 250. removing the spacer will be a quick easy test to see if it's related.

No, typeone, haven't noticed that. I guess it's possible, as there is technically a larger cavity for remaining exhaust gases to circulate in when the bike is not drawing charge in.

On decel, the throttle is close to/at it's idle position, but the motor is turning over quicker - so in essence the motor is running lean for that period, right?

[typeone]

I fitted an X-Trainer pv spacer, too. $11.83AUD & 3 minute job. Noticeable increase off-idle. Not omg, but it's there alright.

I rode my brother's Sherco SE-R 300 a couple of weeks back and apart from the fork being plusher (WP oc, fantastic), I had zero envy of the extra 44 cc.

did you notice an increase in pipe bang on decel with the throttle closed after installing the PV spacer? i'm trying to chase down what's causing this on my 250. removing the spacer will be a quick easy test to see if it's related.

No, typeone, haven't noticed that. I guess it's possible, as there is technically a larger cavity for remaining exhaust gases to circulate in when the bike is not drawing charge in.

On decel, the throttle is close to/at it's idle position, but the motor is turning over quicker - so in essence the motor is running lean for that period, right?

thanks for the feedback. from what i'm reading on the web regarding pipe bang it seems i might be too rich on decel but it sure sounds and feels lean to me. guess i will have to try fiddling with the needle position, air screw adjustments have no effect on the bang. i'm running the JD jet kit which already took my pilot from 35 up to a 38. seems to fit the 'too rich' idea. not sure yet.

[celler]

I run a 42 pilot at 5000ft and 80 F. I doubt the 38 would cause the condition.