52 replies to this topic

[chewy]

Just came back to this forum.. been riding daily as an official in SSDT so got plenty of chances to get intimate with the bike. you may recall we had a long discourse regards smoothing it out. Anyway after fitting the boyenson reeds & 33 pilot jet & retarding it it was way too flat/feeble even for me, but at least I am now able to tweak things to get some power back (I never wanted to reduce the power just to get it controllable /smooth). I'm going to advance the timing untill it starts thinking about kicking back and stalling easy, if that isn't enough I'll run half and half boyenson 2 stage and factory std. reeds. I have avoided getting involved in flywheel mods. because for me smoothing out the pick up (with more flywheel mass) is simply storing up the energy for the overun. It was gratifying to find another fella wanting to smooth out his 2011 250. Just a couple of observations in Scotland was that some riders on Shercos were complaining of fuel starvation when blatting down the road, there was talk of header tank with bypass to return excess fuel to main tank.Fancy Wiggy's chain coming off at town hall brae(last section). the Ossa's sounded spot on and by co incidence they have real/true engine mapping facility. The Greeves's were having thier fair share of troubles.if it doesn't kill them it will make em stronger. Finally thanks to Malc/Rat for the facilities.

[copemech]

chewy, on 10 May 2011 - 03:45 PM, said:

Just came back to this forum.. been riding daily as an official in SSDT so got plenty of chances to get intimate with the bike. you may recall we had a long discourse regards smoothing it out. Anyway after fitting the boyenson reeds & 33 pilot jet & retarding it it was way too flat/feeble even for me, but at least I am now able to tweak things to get some power back (I never wanted to reduce the power just to get it controllable /smooth). I'm going to advance the timing untill it starts thinking about kicking back and stalling easy, if that isn't enough I'll run half and half boyenson 2 stage and factory std. reeds. I have avoided getting involved in flywheel mods. because for me smoothing out the pick up (with more flywheel mass) is simply storing up the energy for the overun. It was gratifying to find another fella wanting to smooth out his 2011 250. Just a couple of observations in Scotland was that some riders on Shercos were complaining of fuel starvation when blatting down the road, there was talk of header tank with bypass to return excess fuel to main tank.Fancy Wiggy's chain coming off at town hall brae(last section). the Ossa's sounded spot on and by co incidence they have real/true engine mapping facility. The Greeves's were having thier fair share of troubles.if it doesn't kill them it will make em stronger. Finally thanks to Malc/Rat for the facilities.

Chewy, seen your vid and bikes smooth. I would not bring timing totally back up, yet still 2-3mm back on the plate from std.

I would suggest you go with the standard Boyesen config first, which means no standard plates,and let themflow a bit more.

As from a 2.9 platform, I cannot give you a direct comparison, yet it has allways seemed to me that the boyeseens seem to provide a good kick in the mid range as the secondary opens and where you need it. Perhaps you could remove one plate?

[copemech]

To add, if one is taking the bike down the road, (road trials) one might want to up the float jet number.

I have no idea what they are coming with, but one report suggested the #250 was sufficient. Yet this is a balancing act.

[Neo]

copemech, on 12 May 2011 - 04:41 AM, said:

Yet this is a balancing act.

What happens if it's too big Cope?

Best of balance.
Neo

[chewy]

copemech, on 12 May 2011 - 04:29 AM, said:

Chewy, seen your vid and bikes smooth. I would not bring timing totally back up, yet still 2-3mm back on the plate from std.

I would suggest you go with the standard Boyesen config first, which means no standard plates,and let themflow a bit more.

As from a 2.9 platform, I cannot give you a direct comparison, yet it has allways seemed to me that the boyeseens seem to provide a good kick in the mid range as the secondary opens and where you need it. Perhaps you could remove one plate?

Good idea to try , by the way did you see the new Cabby replica front exaust?...simlar to that I proposed a few months back.it seems to me they want to get so much fuel into these motors (for power?) they can't get it out fast enough.

[Neo]

chewy, on 12 May 2011 - 07:51 PM, said:

by the way did you see the new Cabby replica front exhaust?... similar to that I proposed a few months back.

What was that Chewy?

Anyone know where I can see some pics of this?

Best of balance.
Neo

[copemech]

Neo, on 12 May 2011 - 04:47 AM, said:

What happens if it's too big Cope?

Best of balance.
Neo

I do not have complete info on any of this, yet apparently the stock float jet on the dell is now smaller(pressure fed via pump), in 200-225 range, and will not flow enough to support road trials or long climbs. Increasing the size to 250 may provide enough fuel(i may recall others such as Splatshop Chris stating larger as the 300) but then one may get into a situation with the downhill slosh and pressure surge that the larger float valve may have difficulty with..

Seems Chris had mentioned just how critical float level was on the VHST, yet did not put a spec to it. I fear the same with the standard carb.

Word I got seems to indicate that the Kiehin handles this much better, and I can only presume that would go for the OKO as well.

Edited by copemech, 13 May 2011 - 03:14 AM.

[copemech]

chewy, on 12 May 2011 - 07:51 PM, said:

Good idea to try , by the way did you see the new Cabby replica front exaust?...simlar to that I proposed a few months back.it seems to me they want to get so much fuel into these motors (for power?) they can't get it out fast enough.

Yes, looks liks S3 issue or summat. I am sure this bike has WAY too much power for me! And where did those forks come from/?