Topic: CB550 - CR29s is this the best it gets? Will CR26s be better street carbs?

[bwaller]

There is usually a "try the track" session during luch hour Sundays. You need to have a bike and decent jacket, helmet & gloves and are out at a "spirited pace" behind a volunteer. The cost is $20 which goes to our Big Brothers/Big Sisters charity.

There are plenty of women racers in the club. Last round the 2013 CSBK CBR250 champion Stacey Nesbitt was racing with us.

Make sure when you have your filters mounted the back of the filter doesn't suck against the stack. It may be necessary to fit screening or something to avoid this. It isn't the case with mine, but just beware. There is 40mm between the filter wall and bellmouth entry on mine, I use a plastic clamp to imobilize the filter and keep it snug against the back of the stack.

[Tintop]

....... Last round the 2013 CSBK CBR250 champion Stacey Nesbitt was racing with us.

Think it should be 2011 CBR125 / 2012 CBR250 Champion Brent.  I know she intimidated a bunch you 'old guys' with her speed, but giving her this year's Championship after one CSBK round?? 

[bwaller]

Yea maybe I jumped the gun there. I'm not intimidated at all, actually it's very cool. I understand she's considering a move to sidecar anyway. 

[akabek]

There is usually a "try the track" session during luch hour Sundays. You need to have a bike and decent jacket, helmet & gloves and are out at a "spirited pace" behind a volunteer. The cost is $20 which goes to our Big Brothers/Big Sisters charity.

There are plenty of women racers in the club. Last round the 2013 CSBK CBR250 champion Stacey Nesbitt was racing with us.

Make sure when you have your filters mounted the back of the filter doesn't suck against the stack. It may be necessary to fit screening or something to avoid this. It isn't the case with mine, but just beware. There is 40mm between the filter wall and bellmouth entry on mine, I use a plastic clamp to imobilize the filter and keep it snug against the back of the stack.

I did not ride track last year but I still have all my gear waiting and ready to go.  I would like to take the CB550 to the track at some point when it is dialed in.  For this "try the track" session does the bike need to be prepped for track? eg. no coolant, lights taped, bolts wire locked etc.

When Stacey was racing I assume she was riding a vintage bike?

This morning I was able to get 3 x 75 pilots so I am short one but I also picked up 4 x 78s just in case.  More testing to come.

[Tintop]

Yea maybe I jumped the gun there. I'm not intimidated at all, actually it's very cool. I understand she's considering a move to sidecar anyway. 

Wouldn't include you in the 'intimidated' group bw, I've watched you race.   Was neat though to see her sweeping by on the outside line in turn 1.

Given the way she moves around on the bike, and drags knees & elbows she'd make a great passenger.  Let's see, another 100lb weight saving should be worth a few more mph top end.

[Kemp]

Pro 6 now has a "sniffer" for their Dynojet and the software. At $100hr it's not a bad idea. If you want to go, I'd like to go with you.

[bwaller]

For the "Try the Track" deal your bike needs to pass tech, but for a street bike taped glass and maybe mirror removal, not too stringent. I doubt you need to lockwire anything.

Stacey raced a TZ one2five. It's great to watch these fast kids. For a little girl she sure has big balls, and I mean that in the nicest kind of way.

[Tintop]

Here's the link for 'Try the Track' - http://www.vrra.ca/?page_id=1611

Stacey raced a TZ one2five. It's great to watch these fast kids. For a little girl she sure has big balls, and I mean that in the nicest kind of way.

Given she came 4th overall, and had the 2nd fastest lap (.03 slower than winning TZ250) I'd second your observation bw.

[akabek]

Pro 6 now has a "sniffer" for their Dynojet and the software. At $100hr it's not a bad idea. If you want to go, I'd like to go with you.

I called PRO6 and they estimated 3 hours labor to jet a bike with carburetor.  If I book an appointment I will let you know but I am not sure if they would do it at a time we could see them in action.

[akabek]

If I installed a CB650 cam into a CB550 motor do I need to degree the cam or does that only apply to aftermarket cams?

[Tintop]

Concensus on the forum is to degree any cam change, if you want to maximize the benefits.

[Kemp]

The CB650 cam is factory original, it should not have to be degreed to get good performance. As Tintop says, consensus is to degree any cam and I've seen stock production roadracers make more power with their cams degreed. You'd have fun doing it and I'm going to try it also with a webcam that I should have done in the first place!!

Pro6 should let you be in there for the run as you will be making jetting changes also. I was there today to run Paul Hewitt's Ducati 350 but we broke (sheared) the key on the crank primary drive so run aborted. The whole point in running it there was to get the jetting dialed in, hp level would be a nice bonus as well.

[akabek]

I will have to read up on how to degree a cam than...

I took a run on the highway and did a plug chop at WOT to check my main jets.  The plugs ranged from good (white with tan color) to a little lean (half the ceramic tip is white) so I am not too far off.  I am running 120s in there now.  I have 122s on hand now but would I be better off going with 125s considering I will be putting foam socks on?

Just to make sure I am reading the carb response correctly:  If I roll on the throttle easy the bike accelerates steadily but if I go wide open throttle quickly the bike stops accelerating until I ease up on the throttle.  This occurs near the 1/4 to 1/2 throttle range.  Does this mean I am rich?

[bwaller]

I will have to read up on how to degree a cam than...

I took a run on the highway and did a plug chop at WOT to check my main jets.  The plugs ranged from good (white with tan color) to a little lean (half the ceramic tip is white) so I am not too far off.  I am running 120s in there now.  I have 122s on hand now but would I be better off going with 125s considering I will be putting foam socks on?
Just to make sure I am reading the carb response correctly:  If I roll on the throttle easy the bike accelerates steadily but if I go wide open throttle quickly the bike stops accelerating until I ease up on the throttle.  This occurs near the 1/4 to 1/2 throttle range. Does this mean I am rich?

If anything the foam filters will restrict slightly so don't go larger on the main until you see.

As far as the bike picking up when you roll off the throttle, yes likely it's rich. You're lowering the needle in the needle jet reducing the taper, leaning it out & picking up rpm's. I experienced this with mine early on & Mike Rieck wisely pointed this out. You might also find it's crisper while it's cool and performs poorly as it heats up.

[Tintop]

+1 on the possible effect of adding socks, and bw's take on what's happening when you ease off the throttle.

[akabek]

Right now I consider the plugs borderline.  One header pipe starting to yellow more than the others and a couple of plugs are too white for my liking.  Assuming the foam filter does restrict slightly I will try 122s.  To balance the low to mid section I will raiser the needle clip to lean it out and hopefully get me to a steady acceleration at WOT.

[akabek]

There have been references made to the Dyna ignition system.  I am using there electronics, 5 ohm coils, wire plugs etc.  Would I be better offer replacing the main unit with the Pamco unit and keeping the rest the same?

[Retro Rocket]

If its firing on all 4 then leave it as it is, your problem is fuel related.

[akabek]

My question was not related to jetting my carbs...more along the lines of a better trouble free ignition down the road.  I see many posts questioning the Dyna system.

[Jerry Rxman Griffin aka MuthaF'er]

There have been references made to the Dyna ignition system.  I am using there electronics, 5 ohm coils, wire plugs etc.  Would I be better offer replacing the main unit with the Pamco unit and keeping the rest the same?

Simple, if it doesn't work replace it otherwise leave it alone.

[Retro Rocket]

My question was not related to jetting my carbs...more along the lines of a better trouble free ignition down the road.  I see many posts questioning the Dyna system.

Yes and if you look into it, lots of those guys had trouble installing them {not all} so as has been suggested, some of those have been screwed up by the installers. if your ignition is fine then leave it alone, sort out your carb problems first... By the way, there was a period where Dyna may have made some dodgey systems, all those before and after are good, so like i said, if its working , leave it alone....

[akabek]

My question was not related to jetting my carbs...more along the lines of a better trouble free ignition down the road.  I see many posts questioning the Dyna system.

if its working , leave it alone....

Sounds good to me...thanks

[MRieck]

Put a relay to the coils.

[Retro Rocket]

Put a relay to the coils.

+1, good idea....

[turboguzzi]

i think we've all seen so many "carburation problems" that were essentially ignition problems that i dont subscribe to the if it works, leave it alone, it's a carb problem. also in this very forum.

just ask Brent how things improved when he switched from Dyna to an OEM system...

seen too many dyna-s sys "working", just not quite right and that type of malfunctions are the real bastards to sort out.