Author Topic: Scotty 3XV SP '91  (Read 27382 times)

Scotty4321

  • Sr. Member
  • ****
  • Location: Newport, S.Wales
  • Posts: 308
Re: Scotty 3XV SP '91
« Reply #180 on: October 22, 2015, 09:15:41 PM »
Been having a potch again and sent the heads off to Martin77 to have some more volume added to them. Hoping to get the thing to rev some more at the top end with the 80CDi. Cheers to Dan for the advice on this.

Have to say a big thanksto Martin, the guy is a legend and turned them around in days, did a great job and at a very reasonable price. Also made me up some extended exhaust flanges to allow his SP pipes to be fitted to R barrels (which do not have the D to O cast adaptors).


I'm told I should now have approx. 11cc fitted head volume and as the exhaust ports have not been raised from standard even though Martin has ported the barrels, the compression ratio is now more or less ideal.
The jetting is still a work in progress and have gone two sizes on the bottom pot so far. I am not too bad on the top cylinder but still too rich on the bottom. This is based on plug chops and the piston tops.



The heads alone have extended the rev range by maybe 700RPM to around 11400 on the clock. Still short of the redline but a lot better. Going to plug chop again tomorrow and if the jetting doesn't help then I may need to try a Zeel as I am  not sure what else to try!!

Warwick

  • Global Moderator
  • Hero Member
  • *****
  • Location: UK
  • Posts: 1560
  • UK
Re: Scotty 3XV SP '91
« Reply #181 on: October 22, 2015, 09:34:21 PM »
The bigger head vols will certainly help it rev. In my experience the SP clocks are much more accurate then the R clocks, so if it's peaking at 11,400 on SP clocks that is not a million miles away. It should merrily over rev well past 12 on the SP clocks though so if it's hitting a brick wall at 11.4 than it's definitely not entirely happy. Probably just carburation set-up, but you will have to tread cautiously as you lean it off if looking for revs that way of course. It'll punish you very quickly if you go too lean...

I use TZ carbs myslef though, so can't offer anything very useful on carb settings on the oe 36mm carbs I'm afraid.   
Still Smoking...

Paul

  • Hero Member
  • *****
  • Posts: 4771
  • Mid Wales, UK
Re: Scotty 3XV SP '91
« Reply #182 on: October 22, 2015, 10:10:54 PM »
Lots of work going on here
Are you sure it's not because of the Std exhaust port height?
Pipes can also limit revs
Jetting
Timing
the twins:-
TZR250 3xv
TZ250 4DP2

maccas

  • Hero Member
  • *****
  • Location: East Yorkshire and Bristol UK
  • Posts: 1769
  • East Yorkshire and Bristol UK
    • GasketGuru
Re: Scotty 3XV SP '91
« Reply #183 on: October 23, 2015, 11:41:30 AM »
Scotty,

I merely passed on advice that was given to me nearly 4 years ago now so no bother there.

Glad it's revving out a bit more now, looks like you are getting close with the set up. Are the powerjets still fitted with blanks or do they have jets in?

Dan

fozzy

  • Hero Member
  • *****
  • Location: South Wales UK
  • Posts: 952
Re: Scotty 3XV SP '91
« Reply #184 on: October 23, 2015, 12:30:45 PM »
scotty the rg500 has arrived from Croatia, not looked at it proper yet but it looks ok..
UK South wales

jcsnook

  • Hero Member
  • *****
  • Location: Tampa Bay, Florida
  • Posts: 1203
Re: Scotty 3XV SP '91
« Reply #185 on: October 23, 2015, 04:28:13 PM »
scotty the rg500 has arrived from Croatia, not looked at it proper yet but it looks ok..

RG500?  Well, well, well!!  Pix please!  I'm having fun with my 4 cylinder 2 strokes these days.  I managed a Bike Night trophy with it!

If your not mixing gas, your not hauling ass!

Scotty4321

  • Sr. Member
  • ****
  • Location: Newport, S.Wales
  • Posts: 308
Re: Scotty 3XV SP '91
« Reply #186 on: October 23, 2015, 06:19:12 PM »
Warwick, It will rev it just doesn't pull, so not really worth going there on the road. It's still pretty rich
and I'm just dropping a single size at a time. Fair point on the clock itself reading lower than an R one.
Had an hour and a half out scratching today, plug chopped on the way back and have dropped to 270 on the bottom pot (3 sizes down now). Need more jets again unless I change an air jet.

Paul, I have no idea what a SP should rev like, will have a scour for some dyno plots. Pipes are Martin's, timing I can't adjust unless I try a stepped key. Jets are coming slowly.

Cheers Dan, Power jets are still blanked. Could well be the answer but not sure I am up for starting over with jetting just yet unless it goes on the dyno. What you thinking, connect them to the CDi so they close at higher revs and lean it out at the top?
Anyone know the relationship between power jet size and Main jet size? Is there a way to roughly calculate how much to go down on mains and up on PJs.

Hi Fozzy, Glad for you mate, not sure I would have sent that money to Croatia!
Snooky, there is a thread with the pics in:
http://pure2strokespirit.net/forums/index.php?topic=3304.0
Have you stripped the TZR motor yet, any news on what's up with it?

Cheers Scotty



Paul

  • Hero Member
  • *****
  • Posts: 4771
  • Mid Wales, UK
Re: Scotty 3XV SP '91
« Reply #187 on: October 23, 2015, 06:36:17 PM »
powerjets are the other one, if left open they rob you of overrev and even top end power
if yours are blanked off this is not a concern
SP porting should be fine, i take that back, didnt think that far, was thinking of R barrels
if your bike is lacking power on acceleration you could be lean on the needle
oh man, it'll just go on and on. you will have to get stuck in and see if 1 change makes it better or worse and go from there
the twins:-
TZR250 3xv
TZ250 4DP2

Scotty4321

  • Sr. Member
  • ****
  • Location: Newport, S.Wales
  • Posts: 308
Re: Scotty 3XV SP '91
« Reply #188 on: October 23, 2015, 07:05:37 PM »
Agree Paul,
I think with the Sugo 80 CDi you can use one of the air jet channels to drive the PJs. They are open most of the time but close at 11400 to give the overrun.
will get a dyno read out done and see what's going on. Scotty

fozzy

  • Hero Member
  • *****
  • Location: South Wales UK
  • Posts: 952
Re: Scotty 3XV SP '91
« Reply #189 on: October 29, 2015, 05:04:23 PM »
Warwick, It will rev it just doesn't pull, so not really worth going there on the road. It's still pretty rich
and I'm just dropping a single size at a time. Fair point on the clock itself reading lower than an R one.
Had an hour and a half out scratching today, plug chopped on the way back and have dropped to 270 on the bottom pot (3 sizes down now). Need more jets again unless I change an air jet.

Paul, I have no idea what a SP should rev like, will have a scour for some dyno plots. Pipes are Martin's, timing I can't adjust unless I try a stepped key. Jets are coming slowly.

Cheers Dan, Power jets are still blanked. Could well be the answer but not sure I am up for starting over with jetting just yet unless it goes on the dyno. What you thinking, connect them to the CDi so they close at higher revs and lean it out at the top?
Anyone know the relationship between power jet size and Main jet size? Is there a way to roughly calculate how much to go down on mains and up on PJs.

Hi Fozzy, Glad for you mate, not sure I would have sent that money to Croatia!
Snooky, there is a thread with the pics in:
http://pure2strokespirit.net/forums/index.php?topic=3304.0
Have you stripped the TZR motor yet, any news on what's up with it?

Cheers Scotty

nope the tzr is off the road, ive insured the tdr for hooning about, but its running like a bag of shit, so carbs are coming off for a strip and clean, I got two carb rebuild kits incase they need it, and my 640 adventure does 60mph flat out, so carb coming off that aswell...


the rg is running
https://www.youtube.com/watch?v=E7rh9Lpg9a4
UK South wales

Paul

  • Hero Member
  • *****
  • Posts: 4771
  • Mid Wales, UK
Re: Scotty 3XV SP '91
« Reply #190 on: November 05, 2015, 03:19:52 PM »
the twins:-
TZR250 3xv
TZ250 4DP2

fozzy

  • Hero Member
  • *****
  • Location: South Wales UK
  • Posts: 952
Re: Scotty 3XV SP '91
« Reply #191 on: November 05, 2015, 09:06:42 PM »
the rg is running
https://www.youtube.com/watch?v=E7rh9Lpg9a4

shit! im envious

had a offer to sell it, not sure what to do...not advertised it, just a guy I got talking to in a bike shop..
UK South wales

jcsnook

  • Hero Member
  • *****
  • Location: Tampa Bay, Florida
  • Posts: 1203
Re: Scotty 3XV SP '91
« Reply #192 on: November 05, 2015, 09:22:36 PM »
Oh man...what are the chances of you getting another one of those?  That's a pretty sweet custom build there, be hard for me to sell it straight away.

I must say though, that those clip-ons look to be mounted VERY LOW to fit in the fairing.  It doesn't look real pleasant to ride like that.  Am I wrong, or is it not too bad?

Love the ending on your video  ;D
If your not mixing gas, your not hauling ass!

fozzy

  • Hero Member
  • *****
  • Location: South Wales UK
  • Posts: 952
Re: Scotty 3XV SP '91
« Reply #193 on: November 05, 2015, 11:08:55 PM »
Oh man...what are the chances of you getting another one of those?  That's a pretty sweet custom build there, be hard for me to sell it straight away.

I must say though, that those clip-ons look to be mounted VERY LOW to fit in the fairing.  It doesn't look real pleasant to ride like that.  Am I wrong, or is it not too bad?

Love the ending on your video  ;D

I thought the same, but when I sat on it, it wasn't to bad, I had a rd500 hybrid that was much worse, one of the reasons I sold it, I've got another rg500 that's stock apart from pipes, the guy may want that instead, not sure what to do, but I'm selling
Sp1
Rs250 x2
R1 4xv x2
 Just sold 2x rd Ypvs

It's a pain when you have a few bikes, keeping battery's charged and running them, and  tax insurance so I'm going to keep 3 0r 4

So keeping 3xv tdr my other sp1 ktm adventure and a Ypvs build and maybe one rg500
UK South wales

jcsnook

  • Hero Member
  • *****
  • Location: Tampa Bay, Florida
  • Posts: 1203
Re: Scotty 3XV SP '91
« Reply #194 on: November 06, 2015, 02:50:05 PM »
I thought the same, but when I sat on it, it wasn't to bad, I had a rd500 hybrid that was much worse, one of the reasons I sold it, I've got another rg500 that's stock apart from pipes, the guy may want that instead, not sure what to do, but I'm selling
Sp1
Rs250 x2
R1 4xv x2
 Just sold 2x rd Ypvs

It's a pain when you have a few bikes, keeping battery's charged and running them, and  tax insurance so I'm going to keep 3 0r 4

So keeping 3xv tdr my other sp1 ktm adventure and a Ypvs build and maybe one rg500


Ok, I understand now  ;D  As long as you keep one Gamma then!  How much to ship the Sheene rep to the states?  ;)

I know how you feel.  I've got about 10 titled bikes myself, and about 7 of them are currently on the road with license plates, which must be renewed every year on your birthday (here in the states).  I dread birthdays even more these days.  No gifts...just give me money!  LOL!   
If your not mixing gas, your not hauling ass!