Topic: Mike, Sean, anyone else who can tune CR carbs.

[sparty]

Okay, my Hot Rod engine is finally broken-in.  Just put the last few miles on it today.  Now I need to really get the tuning correct.  It is running rich (which was safe during break-in) but now I need to lean it out some.  I need to order some Iridium plugs (Mike, can you recommend the correct number for me?  The plugs that are in the bike now allow it to run a bit cooler because of the compression.)  I am wondering if I can tune the carbs just by moving the clip position without a rejet?  Sean, you should be a big help here.
I have jets one size up and one size down if needed.  Now that summer temps are here, I am thinking of a heavier oil as well.  The 10w40 is getting pretty thin in these temps.

Currently I continue to scare the crap out of myself on the bike because of the power, I am wondering how much more power it will have running at the right ratio?  I am a bit scared to find out.  I did a few pole to pole blasts this afternoon and saw the speedo climb by 30 MPH in a few blinks.  3rd gear acceleration is a terror.

A Nissan 350Z tried to entice me into a sprint.  Dumb move on his part, I let him smoke his tires and I pulled away nice and slow.

Sparty 

[MRieck]

Okay, my Hot Rod engine is finally broken-in.  Just put the last few miles on it today.  Now I need to really get the tuning correct.  It is running rich (which was safe during break-in) but now I need to lean it out some.  I need to order some Iridium plugs (Mike, can you recommend the correct number for me?  The plugs that are in the bike now allow it to run a bit cooler because of the compression.)  I am wondering if I can tune the carbs just by moving the clip position without a rejet?  Sean, you should be a big help here.
I have jets one size up and one size down if needed.  Now that summer temps are here, I am thinking of a heavier oil as well.  The 10w40 is getting pretty thin in these temps.

Currently I continue to scare the crap out of myself on the bike because of the power, I am wondering how much more power it will have running at the right ratio?  I am a bit scared to find out.  I did a few pole to pole blasts this afternoon and saw the speedo climb by 30 MPH in a few blinks.  3rd gear acceleration is a terror.

A Nissan 350Z tried to entice me into a sprint.  Dumb move on his part, I let him smoke his tires and I pulled away nice and slow.

Sparty 

Art....Denso IX-27's I believe. I'll verify tomorrow. I'll PM you with some carb suggestions.
   Mike

[sparty]

Great!  I was about to bump this post.

Art

[scondon]

 Denso XI-27 it is (D9-EA equivalent), also NGK D9-EIX but have never used these.

  I don't know how you're carbs are set up now Sparty but I found out something interesting once the temps started to climb this Summer. I've had to richen things up a tad from the Winter time settings. It's kind of counter-intuitive to me considering what I've heard about cold air containing more oxygen(or something like that) and a cold engine needing the choke to run, but I just do what the bike tells me to do.

 It could have nothing to do with the heat at all but since I ride every day, and therefore keep a good overall eye on conditions over a period of time, it is making sense to me.

   Be aware that these carbs have a big overlap between the systems. A big change in the idle mixture can affect all the way up to 1/2 throttle and a main jet change can affect nearly all the way down to 1/2 throttle, at least in my limited experience.

   Mike made that monster of a gas oven(haha) so I'll definitely defer to him for any changes to be made in feeding it

    In the meantime Sparty, find some good open road and twist that #$%* up in 4th and 5th    2nd and 3rd will eat any mix you throw at it and spit out raw power. any rich/lean conditions seem more noticable in the higher gears.

[sparty]

Denso XI-27 it is (D9-EA equivalent), also NGK D9-EIX but have never used these.

  I don't know how you're carbs are set up now Sparty but I found out something interesting once the temps started to climb this Summer. I've had to richen things up a tad from the Winter time settings. It's kind of counter-intuitive to me considering what I've heard about cold air containing more oxygen(or something like that) and a cold engine needing the choke to run, but I just do what the bike tells me to do.

 It could have nothing to do with the heat at all but since I ride every day, and therefore keep a good overall eye on conditions over a period of time, it is making sense to me.

   Be aware that these carbs have a big overlap between the systems. A big change in the idle mixture can affect all the way up to 1/2 throttle and a main jet change can affect nearly all the way down to 1/2 throttle, at least in my limited experience.

   Mike made that monster of a gas oven(haha) so I'll definitely defer to him for any changes to be made in feeding it

    In the meantime Sparty, find some good open road and twist that #$%* up in 4th and 5th    2nd and 3rd will eat any mix you throw at it and spit out raw power. any rich/lean conditions seem more noticable in the higher gears.

I wish that I could find a cop free open road to open it up in 4th and 5th!  In 4th I am at 80mph and still only running 5000rpm.  I am taking the bike out in a little while to give it a go.

Art

[scondon]

Denso XI-27 it is (D9-EA equivalent), also NGK D9-EIX but have never used these.

  I don't know how you're carbs are set up now Sparty but I found out something interesting once the temps started to climb this Summer. I've had to richen things up a tad from the Winter time settings. It's kind of counter-intuitive to me considering what I've heard about cold air containing more oxygen(or something like that) and a cold engine needing the choke to run, but I just do what the bike tells me to do.

 It could have nothing to do with the heat at all but since I ride every day, and therefore keep a good overall eye on conditions over a period of time, it is making sense to me.

   Be aware that these carbs have a big overlap between the systems. A big change in the idle mixture can affect all the way up to 1/2 throttle and a main jet change can affect nearly all the way down to 1/2 throttle, at least in my limited experience.

   Mike made that monster of a gas oven(haha) so I'll definitely defer to him for any changes to be made in feeding it

    In the meantime Sparty, find some good open road and twist that #$%* up in 4th and 5th    2nd and 3rd will eat any mix you throw at it and spit out raw power. any rich/lean conditions seem more noticable in the higher gears.

I wish that I could find a cop free open road to open it up in 4th and 5th!  In 4th I am at 80mph and still only running 5000rpm.  I am taking the bike out in a little while to give it a go.

Art

   I hear ya, Sparty. After getting away with some insane #$%* this Spring I'm looking to switch to the track before my luck runs out. Fortunately there is a lot of empty space surrounding the big cities here in California so an hours trip will get me to some decent high speed roads(no intersections, few turnouts, decent visibility, etc...).

[eurban]

I wish that I could find a cop free open road to open it up in 4th and 5th!  In 4th I am at 80mph and still only running 5000rpm.  I am taking the bike out in a little while to give it a go.

Art

Is your bike really geared that tall or are you mistaken / exaggerating?  My 78k with stock ratios is doing about 5K rpm at 70mph in 5th.  This would be considered a setup biased for relaxed highway cruising.  If you are really running 5k rpms at 80mph in 4th then you might want to reconsider your gearing.  Your flowed / balanced engine with its 4-1 exhaust and CR carbs should be capable of making big / reliable power at RPMS much higher than a stock engines power peak; why on earth are you running such tall gearing???   

[scondon]

I wish that I could find a cop free open road to open it up in 4th and 5th!  In 4th I am at 80mph and still only running 5000rpm.  I am taking the bike out in a little while to give it a go.

Art

Is your bike really geared that tall or are you mistaken / exaggerating?  My 78k with stock ratios is doing about 5K rpm at 70mph in 5th.  This would be considered a setup biased for relaxed highway cruising.  If you are really running 5k rpms at 80mph in 4th then you might want to reconsider your gearing.  Your flowed / balanced engine with its 4-1 exhaust and CR carbs should be capable of making big / reliable power at RPMS much higher than a stock engines power peak; why on earth are you running such tall gearing???   

   Good point eurban, missed that one. Sparty, set the rev limiter to 8500 and see what your tach is reading when you hit it. I've found the stock tachs to be wildly inconsistent due to age or whatever. With 17/48 gearing(2.86) I am at 5000rpm in 5th at 73mph, electronic tach reading the coil pulse.

[mlinder]

Yeah.. that would put you at 160mph at 10k in 4th

Kinda tall gearing there....

Anyway, see if you can get a track day in. Ambulances are nearby, and there is no cross/oncoming traffic.

[Dave-and-his-550]

This thread intrigues me. I wanna learn more about gearing and ratios and how it coincides with speeds and RPM's or what have you. Anybody got some good tech guides available online about this stuff?
 

[scondon]

 Here's an interesting calculator that gives answers in KM/H

http://www.gearingcommander.com/


 Pen and paper kind of guy?

http://www.msgroup.org/tip.aspx?num=094

[sparty]

Denso XI-27 it is (D9-EA equivalent), also NGK D9-EIX but have never used these.

  I don't know how you're carbs are set up now Sparty but I found out something interesting once the temps started to climb this Summer. I've had to richen things up a tad from the Winter time settings. It's kind of counter-intuitive to me considering what I've heard about cold air containing more oxygen(or something like that) and a cold engine needing the choke to run, but I just do what the bike tells me to do.

 It could have nothing to do with the heat at all but since I ride every day, and therefore keep a good overall eye on conditions over a period of time, it is making sense to me.

   Be aware that these carbs have a big overlap between the systems. A big change in the idle mixture can affect all the way up to 1/2 throttle and a main jet change can affect nearly all the way down to 1/2 throttle, at least in my limited experience.

   Mike made that monster of a gas oven(haha) so I'll definitely defer to him for any changes to be made in feeding it

    In the meantime Sparty, find some good open road and twist that #$%* up in 4th and 5th    2nd and 3rd will eat any mix you throw at it and spit out raw power. any rich/lean conditions seem more noticable in the higher gears.

I wish that I could find a cop free open road to open it up in 4th and 5th!  In 4th I am at 80mph and still only running 5000rpm.  I am taking the bike out in a little while to give it a go.

Art

Typo.  should be 7000rpm in 4th = 80MPH.  Redline is 10000rpm.  17 tooth front sproket.

[Terry in Australia]

With 17/48 gearing(2.86) I am at 5000rpm in 5th at 73mph, electronic tach reading the coil pulse.

Yep, that sounds right Sean, with 18/48 gearing, I got 60 MPH in 5th gear @ 4000 RPM, from my stock K1 and from memory, around 80 MPH @ 5000 RPM.

My K1 that I have now with the hot 836cc engine has a 16 inch back wheel with a 140/80-16 tire, so it drops the gearing slightly, to around your numbers. Now what the hell is "a set of crossovers"? Ha ha, Cheers, Terry.

[MRieck]

 I'm definitely above 5,000 at 80mph. For sure.

[mlinder]

That would put you at 10.5k at 120mph, just about perfect

[Terry in Australia]

I'm definitely above 5,000 at 80mph. For sure.

What gearing are you running Mike?

[MRieck]

I'm definitely above 5,000 at 80mph. For sure.

What gearing are you running Mike?

17/50 Terry (2.94). It is right in the fat part of the torque at 65-70mph. I roll it on and it pulls hard brother.

[Terry in Australia]

Thanks Mike, I might change the 18 T front sprocket to 17 and see how that affects things with the 16 inch rear wheel.

I've got a really trick 18 inch rear wheel with 4 inch wide Borrani rim and lightweight cast iron race disc that I'm gonna install one day, when I do that I'll go for 17/50 like your set up. Cheers, Terry.

[scondon]

Now what the hell is "a set of crossovers"? Ha ha, Cheers, Terry.

  They're PIPES fer chris'sakes!!! Headers that cross over each other. Now you and my78k get yer heads out of the toilet or I'm gonna tell my ma

I'm definitely above 5,000 at 80mph. For sure.

What gearing are you running Mike?

17/50 Terry (2.94). It is right in the fat part of the torque at 65-70mph. I roll it on and it pulls hard brother.

   Crap Mike, I skitter enough in 2nd and 3rd running 17/48. Think I could wheelie with 17/50 ? 

    At some point rear tire size must enter the equation,no?  I mean, changing from a 130/90/18(25.25 dia.) to a 110/90/18(24.4 dia.) would "lower" the gearing a bit too wouldn't it?


   Just walkin' all over your thread 'til the State Troopers release ya, Sparty     OK, maybe not so funny. Hope the speed runs went alright.

[754]

17/54 is excellent for around town...

and 1/8 mile..

[Sam Green Racing]

That was my thoughts as well Frank, Chris Peaked the old motor in top on the quarter on that gearing, toped out about 95mph with Chris on it and around 103 with me.
It uses 16/39 over the quarter now with terminals between 111 and 117mph in fourth gear.

Sam.

[754]

I went on a 250 mile ride , each way ..with that gearing. pulls hills really good and passes cars quick..

I was thinking of shortening my swingarm to be able to run that gearing & still use a 120 tooth chain..

[Terry in Australia]

Now what the hell is "a set of crossovers"? Ha ha, Cheers, Terry.

  They're PIPES fer chris'sakes!!! Headers that cross over each other. Now you and my78k get yer heads out of the toilet or I'm gonna tell my ma


   Just walkin' all over your thread 'til the State Troopers release ya, Sparty     OK, maybe not so funny. Hope the speed runs went alright.

Oh, ok Sean, sorry mate, please don't tell your ma, I don't want her putting her size 14 Army boot up my ass, ha ha!

So you want those pipes I had on my K1? The "Peter Allen" (no, not that Aussie singer, the other one) race pipes, or the drag pipes? (both have (crossovers) I'll do you a deal mate, you send me those crappy, ill fitting ol' X Pipes, and I'll send ya whichever set you'd prefer, ok? And I'll tell Dennis to back off too, or I'll tease him about his (lack of) fireblade riding skills, ha ha!

And don't worry about Sparty, his wife is a judge I think, so he's prolly got a "get out of jail free" card in his wallet, ha ha! Cheers, Terry.

[sparty]

Now what the hell is "a set of crossovers"? Ha ha, Cheers, Terry.

  They're PIPES fer chris'sakes!!! Headers that cross over each other. Now you and my78k get yer heads out of the toilet or I'm gonna tell my ma


   Just walkin' all over your thread 'til the State Troopers release ya, Sparty     OK, maybe not so funny. Hope the speed runs went alright.

Oh, ok Sean, sorry mate, please don't tell your ma, I don't want her putting her size 14 Army boot up my ass, ha ha!

So you want those pipes I had on my K1? The "Peter Allen" (no, not that Aussie singer, the other one) race pipes, or the drag pipes? (both have (crossovers) I'll do you a deal mate, you send me those crappy, ill fitting ol' X Pipes, and I'll send ya whichever set you'd prefer, ok? And I'll tell Dennis to back off too, or I'll tease him about his (lack of) fireblade riding skills, ha ha!

And don't worry about Sparty, his wife is a judge I think, so he's prolly got a "get out of jail free" card in his wallet, ha ha! Cheers, Terry.

Yes my wife is a Judge, but she has made it very clear that if I get pinched, I will pay all the fines and have to do community service.  She knows me too well.

Art

[sparty]

Hot Rod ride report 6/24/08.  Just returned from the BEST ride of the season so far.  Temp 73 degrees, humidity 38% = tons of power!  Went with my friend Rob, who rides a DRZ400SM (SM=super moto).  Filled up the tank with 94 octane and took off for winding roads.  Rob was in front and was just hammering the corners.  It took everything I had, everything, just to keep him in sight.  On the straight sections I was back on his tail quickly, and then he would drop me again.  I was playing it semi-safe, but had it leaned over pretty well.  The “chicken” strips are now gone from the sides of my tires.   

What a blast!  Apex heaven, tight 90 degree turns in some sections and rises that Rob would wheelie over.  Pretty fun to watch a good rider at work.  We got into one section of left turn, right turn, big sweeping left, short right and DEER on the side of the road.  My heart jumped a beat.  Heavy brakes, down shift and slow until we were through the wooded sections.  Whew!  (deer looked all sleek with their summer coats).  I had a slight power wheelie from 2nd to 3rd  with a heavy throttle. (where did that come from?!  Lets do it again.)  Ran it up to 8500 rpm and then hit 4th – love the undercut tranny, just perfect solid engagement every time.  Forget about messing with the jetting and needle clips, the power is STRONG in 4th and 5th.  Throttle response in top gear roll on is impressive – it responds with zero hesitation.  Not enough room to get it past 7000rpm in 5th, but it was illegal as all heck already.  I took the lead on the way home and Rob told me he had his bike pegged in top gear just to keep me in sight.  I gave it the berries in 5th and was running way up there and then some on a nice two mile straight section, no other cars in front of me.  The wind blast was pushing hard and my chin was on the tank.  You could just about hear the K&N pods sucking air, very unique and awesome sound – hard to describe, but sort of like a whistle.  SWEET.  The engine stayed pretty cool because of the air temp.  The shaded country road sections were even cooler.  Glad I took advantage of this day.

Art

[scondon]

 Excellent news, Sparty   Especially the part about not needing to touch the carbs. They are easy to get to the jets and needles for tuning, but better that it runs great as is

  Those super moto bikes are something else aren't they? Especially when ridden by an experienced rider. I can't keep up with a particular KTM 600 and even with a 1/2 mile lead in the straights it's inevitable that he'll blow past me in the twisty stuff. At least I've got it up to a matter of minutes now, instead of seconds

   I won't post the estimated speed at 7000rpm in 5th just in case your wife is reading over your shoulder. But this is where I enjoy these motors the most. In 2nd and 3rd I'm hanging on for dear life while scouting every bump and turn as it rushes up faster and faster. In 4th and 5th you just HAVE to be on a road that's open enough to see waaaaaay ahead and this is where I can relax the concentration just enough to enjoy the 4 cylinder symphony of the motor at high rpm's.

   Glad to hear that after all this time you were able to give the bike a good thrashing. I'm sure you'll hold that buzz for a few days at least. A few more weekend adventures and you might want to hit a track day just to enjoy that feeling without all the stress and worry.

   Finally getting your moneys worth, way to go Sparty

[Sam Green Racing]

Never mind the track day, get it on a drag strip

Good report there Art, when is it gonna hit the dyno, can't wait to see what she makes.

Sam.

[sparty]

Those super moto bikes are something else aren't they?

I won't post the estimated speed at 7000rpm in 5th just in case your wife is reading over your shoulder.

Yes those super motos are the real deal in the twisties.  The speed at which they corner is INSANE - double what the CB will do.

Just for a comparison, what is your 5th gear speed at 7000?  My speed was bouncing around alot past the magic number.

Art

[sparty]

Never mind the track day, get it on a drag strip

Good report there Art, when is it gonna hit the dyno, can't wait to see what she makes.

Sam.

Dyno report is coming next month I hope.  Drag strip this Friday night if the weather permits.  1/4 mile time should be interesting.  I practiced a few launches yesterday.  The clutch grabs really well due to the HD springs.  I just need to get it right so I don't roll over.  I am trying to figure out what rpm to let it out at.

Art

[Sam Green Racing]

What gearing are you running Art ?

Sam.

[sparty]

What gearing are you running Art ?

Sam.

17-48

[scondon]

What gearing are you running Art ?

Sam.

17-48

WooHoo, the magic #

Those super moto bikes are something else aren't they?

I won't post the estimated speed at 7000rpm in 5th just in case your wife is reading over your shoulder.

Just for a comparison, what is your 5th gear speed at 7000?  My speed was bouncing around alot past the magic number.

Art

   I'll tell ya tomorrow after I get to work

   I'm thinking somewhere around 120mph.

[sparty]

   I'll tell ya tomorrow after I get to work

   I'm thinking somewhere around 120mph.
[/quote]

Slow poke.  I was higher today.

[Sam Green Racing]

Try at about 4,500 or 5,000 if your brave any more and you will have it wheelying like crazy or spinning up.

Sam.

[scondon]

   I'll tell ya tomorrow after I get to work

   I'm thinking somewhere around 120mph.

Slow poke.  I was higher today.
[/quote]

   Them's racin' words, pardner. Choose yer weapon

[Jerry Rxman Griffin aka MuthaF'er]

Congratulations Sparty. The fruit of your labor (and money) is finally realized. Now that it's broken in I can't wait to hear what you have to say when it hits the limiter at 10,000 rpm. It's pretty sweet to see the tach needle emerging from the redline zone on the top side.

[scondon]

..... I can't wait to hear what you have to say when it hits the limiter at 10,000 rpm. It's pretty sweet to see the tach needle emerging from the redline zone on the top side.

   Can ya send me an old K tach so that I can experience it too, Jerry. Frickin' F tachs go from 9.5-10.5 and I've been a bit hesitant to hit 11 grand on the Daily Rider(pre-Sumbich 836, no rev limiter).

[Jerry Rxman Griffin aka MuthaF'er]

You just need an old F tach that starts at 8500 

[scondon]

   I'll tell ya tomorrow after I get to work

   I'm thinking somewhere around 120mph.

Slow poke.  I was higher today.
[/quote]

7000rpm in 5th is only 105mph. We use the same gearing(17/48) so the only difference between our bikes would be 5th gear ratio and tire size. Are you running a stock transmission? what year?

120/90/18 on my rear