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

[MRieck]

That's an old pic Brent.....I see the 2000 box.

[akabek]

That's an old pin Brent.....I see the 2000 box.

Hah, I am sure he is hiding his secrets....

New update, I removed the steel dragon stacks, put the original stacks in and changed my jetting to 65, 120, YY8 5th position.  Molly "wife's nickname for the CB550" is now a rocket ship.  The only issue now is that I had a little back firing cruising at low speed and it  bogs if I try to go WOT early on so the pilot could go down to a 60.  Thanks for everyone's help so far but I still need to deal with getting a filter.

[akabek]

My filters are from ITG. www.itgfilters.net.  Have a look around there are other options apart from the ones I use. The trick is to have as much room between the bellmouth and the back of the inside of the filter. I think I have 45mm, not a lot but space is tight as you know. I forget what the CR stacks are like but the folks at ITG can surely suggest something.

It is with certainty that some think I'm nuts too for using these on a race bike and I'll bet there's a hp or two to be found running without them. However I have seen the strangest things ingested into an engine with open carbs.

Truth is your screens will keep low flying birds out, but the damaging material will be sucked right through. I'm with you though, use some sort of filter.

I'm sorry man you probably feel like we're picking on you, not the case. TG's latest suggestion on jetting awaits!

I just sent ITG an email to see what they suggest for a foam element.  I have 21mm between the outer stack bell end and the bike frame..not much space.  Will the foam element change my jetting much?  What oil do you use for the foam element?

[bwaller]

I use K&N oil and cleaner.

[Tintop]

Re filter oil, any brand is OK but it must be foam filter oil, not the oil used for paper filters like K&N's. 

The Canadian distributor for ITG is - http://www.jonnichols.com/  He's closer, and shipping costs will be less.

[Tintop]

I use K&N oil and cleaner.

The solvents in the K&N oil will kill the glues used in your filter bw.

[akabek]

Re filter oil, any brand is OK but it must be foam filter oil, not the oil used for paper filters like K&N's. 

The Canadian distributor for ITG is - http://www.jonnichols.com/  He's closer, and shipping costs will be less.

I will check with Jonnnichols to see if he carries the filter I need.

Should I expect much of a change in jetting using these foam elements?

[Tintop]

I used an ITG, haven't found any difference with my sidecar, or CB550.  That said, I also have slightly more than the minimum distance internally above the stacks. 

[akabek]

What is the minimum distance?  Should I keep the distance equal for all filter installs?  I only have 21mm between the bell end and the frame on either end.

[turboguzzi]

New update, I removed the steel dragon stacks, put the original stacks in and changed my jetting to 65, 120, YY8 5th position.  Molly "wife's nickname for the CB550" is now a rocket ship.  The only issue now is that I had a little back firing cruising at low speed and it  bogs if I try to go WOT early on so the pilot could go down to a 60.  Thanks for everyone's help so far but I still need to deal with getting a filter.

glad that long distance counseling works (sometimes...) maybe play with needle heights a bit and it will all fall into place

[akabek]

New update, I removed the steel dragon stacks, put the original stacks in and changed my jetting to 65, 120, YY8 5th position.  Molly "wife's nickname for the CB550" is now a rocket ship.  The only issue now is that I had a little back firing cruising at low speed and it  bogs if I try to go WOT early on so the pilot could go down to a 60.  Thanks for everyone's help so far but I still need to deal with getting a filter.

glad that long distance counseling works (sometimes...) maybe play with needle heights a bit and it will all fall into place

Changing the needle height would be easier than swapping the pilots out.  I will try 4th position and see how that goes.  Today I will see if I can hunt down some foam filter elements.  It will not look as nice as the Steel Dragon setup but it will keep the crud out.

[FunJimmy]

Great progress sorting through the jetting issues but you've failed to mention the effect on idle. Are you able to hold a normal idle?

[akabek]

Great progress sorting through the jetting issues but you've failed to mention the effect on idle. Are you able to hold a normal idle?

I have not had time to zero in on idle.  First I need to nail down my jetting....still rich on the low end.  Although I did notice I could get the idle down a little lower after my last ride. I will let you know how it turns out.

[turboguzzi]

best idle tuning tip for street use of CRs? get a remote idle stop adjuster

http://www.dynoman.net/images/carbs/keihin/KEI_remote_adj_small.jpg

[akabek]

best idle tuning tip for street use of CRs? get a remote idle stop adjuster

http://www.dynoman.net/images/carbs/keihin/KEI_remote_adj_small.jpg

I already installed one....that option is a must have for sure with CR carbs.

Last night I moved the needle position from 5th to 4th position (leaner) and the hesitation was more noticeable.  Tonight I am going to change my pilots from 65s to 60s.  Hopefully the rain holds up until I can get a test ride in. 

I also ordered the foam socks from jonnichols.com so hopefully I will have them before the weekend.  For the oil treatment of the foam socks I picked up a can of PJ1 foam filter treatment.

[Jerry Rxman Griffin aka MuthaF'er]

Now that you've leaned out the middle and the hesitation is MORE noticeable with this will you try the next size larger mains since there is overlap before you do any other changes like the foam socks? I limit my stuff to only one change at a time.

CARBS SUCK! 

[akabek]

Now that you've leaned out the middle and the hesitation is MORE noticeable with this will you try the next size larger mains since there is overlap before you do any other changes like the foam socks? I limit my stuff to only one change at a time.

CARBS SUCK! 

I follow the same rule, one change at a time.  I got rid of the bling and when back to the baseline jetting and CR stacks.  Before I put the foam socks on I want to get the jetting right without them so I have a base line and I know what the bike "should" feel like through the gears.

In the last couple of days I have been playing with the needle clip position.  Right now the bike performs well 1/3 throttle and up but I experience hesitation if I try to excelerate to quickly from a stopped position.  If I ease up on the throttle is begins to accelerate again so my pilot is rich.  Tonight I am going drop by pilot from a 65 to a 60.  If the weather cooperates I will do another test ride but the jetting is getting closer.

Hopefully adding the socks will only require slight changes...

[Tintop]

I don't think the sock(s) will cause any change.  The ITG filter on my 550 is rated to flow enough air to support 300hp.

[akabek]

I don't think the sock(s) will cause any change.  The ITG filter on my 550 is rated to flow enough air to support 300hp.

I should be getting more that that on my bike....

My socks showed up today....you were not kidding he is quick to deliver..

[Tintop]

akabek, what are you doing the weekend of July 6/7??  The VRRA Vintage races are at Shannonville, and both myself (sidecar) & bwaller (CB550) will be there.

[akabek]

akabek, what are you doing the weekend of July 6/7??  The VRRA Vintage races are at Shannonville, and both myself (sidecar) & bwaller (CB550) will be there.

That may be doable.  Let me see if I can work in one of those days.  Do I need to buy a ticket to get in?  I assume I can buy at the gate as well.

So my ability to jet a carb went out the window tonight.  When I pulled the pilot out I actually had a 70 installed so I dropped down to a 65.  This just made things worse.   When I was running 120, 70, 5th position the hesitation was right out of the gate for a slight second.  I thought if I am accelerating WOT and the bike hesitates until I easy up on the throttle I am running rich.  I guess I was running lean on the first quarter throttle.

Now I am going to go back to 120, 70, YY8 but 6th position....The upside is I am getting better switch jet and needle settings.

[akabek]

Tonight I left off with 120, 72, YY8 5th position.  1/3 and up the bike is a rocket I still have hesitation right at the start.  Next I will try 6th position and if that does not work out I may have a 75 pilot I can drop in.  I am noticing I can get the idle down lower as the bike runs better.  Sorry for the play by play but it helps me record what I am doing.

I am quite surprised at the performance for a vintage bike.  I can see this being a blast to ride at a track.  I may have to grab the 1 piece suite and trailer up....   

When I put the sock on how much room do I need to leave between the end of the stack bell and the inner filter end?

[Tintop]

When I put the sock on how much room do I need to leave between the end of the stack bell and the inner filter end?

I think further back you said you had about 30mm to the frame, use all the space you have.  Ideally you want a minimum equal to (or greater than) the venturi size.

I think spectators are free on the Sunday (7th).  I'll check and let you know.

[akabek]

When I put the sock on how much room do I need to leave between the end of the stack bell and the inner filter end?

I think further back you said you had about 30mm to the frame, use all the space you have.  Ideally you want a minimum equal to (or greater than) the venturi size.

I think spectators are free on the Sunday (7th).  I'll check and let you know.

The steel dragon stacks only left me with 21mm.  I will take a new measurement since I have the CR stacks on it now.  I think the original stacks are shorter so I should have a little more space.

I should be a go for that weekend.  My wife wants to eventually ride track so she is interested in checking it out.  She use to race pro level snowcross so it may be in her blood.  Do any women ride with the VRRA?   After starting my CB550 build I was going to look into the VRRA as I sold my last track bike a year ago.  Sounds like a fun race event.

[akabek]

If anyone knows a Canadian source for CR29 pilot jets let me know.  The Canadian distributor Motovan only goes up to 70 pilots and I looking for 75s.  I am going to check with Winners Circle Canada tomorrow but if they do not have them I will need to order them across the border.