Topic: Re-Jetting my 74 CB550 project

[CharlieVT]

Gents,
First, thanks for this site and all the help and resources I have found here. I am not new to Hondas and I am not new to rebuilding old bikes, but I am new to rebuilding old Hondas   This is a great site and you guys are a class act. ("guys".... any women on here?)
Since I have recently bashed "old byke barn" here, let me say that I was very pleased with the communication via email, timely service, and the exhaust system I got from Loud Fast'n Ugly. I asked a few questions via email, got prompt responses, and ordered a 4-1 exhaust from that business. I really like the fit and sound of the exhaust I got from Loud, Fast'n Ugly (actually it isn't loud, and has a very nice throaty, not too loud, sound).  Good communication, quick shipping, and good product from Loud, Fast'n Ugly. They sent me some info on re-jetting for my new exhaust and I have miss-placed it (it will turn up, things always do).
Which brings me to my question (forgive the verbosity, it is my style):
Where do you suggest I look to buy jets for my CB550?
Has anyone else bought a 4-1 exhaust for a CB550 from Loud Fast'n Ugly, and what did you do to dial in the carbs?
By the way, my CB550 project (basically stock with low bars and a small faring) can be seen at:
http://home.earthlink.net/~cmiddleton01/bmwairheads/id7.html

Thanks again and...
Regards,
Charlie

[heffay]

jets are a pretty hot item and fairly well stocked by local shops (at least that is my experience)

just tell them what brand carb they're going into and, what bike the carbs are off of so they have an idea of what style jets you're after

best of luck,

heff

[hymodyne]

welcome to the site. It is a great resource.

nice bike.

hym

[jmastropole]

Hi Charlie,

I also have a '74 550 and recently bought some carb rebuild kits from Sirius in Canada.  They also carry main jet tuning kits.  The kit has 2 each of sizes 100, 110, 120 125 and 130 (stock size is 100) ... so you will need two kits at $35 each (Canadian?).  The kit you need is shown in the following link ...

http://www.siriusconinc.com/carb/parts.asp?category=2&supplier=1&id=1

I am close to buying the same exhaust system from Loud Fast etc., so I will be going through the same re-tune ordeal.  Sure glad to hear you are happy with that system (and especially glad to hear they are not loud).  I suspect that the original 100 size jets will be OK with the new exhaust and that 110 would be the largest size we might need to get things just right.

Too bad the original exhaust systems are so darn expensive and hard to find; mine are just starting to rust-out ... I had to register the bike as an "antique" since I could not pass Virginia state inspection with a leaky exhaust system.  Otherwise my 550 is in "like-new" condition with only 8K miles (I bought this bike in 1974 and it has been carefully stored for the last 30 years ... 100% stock for now).  I just brought it out of storage this winter and only had to rebuild the master brake cylinder and clean the carbs (and replace all the carb o-rings) to get it on the road.

Regards, Jim

'74 CB550K
'05 Yamaha FJR1300

[clarkjh]

Charlie

Looks good

James

[heffay]

charlievt~
i also know for a fact that many of us on the forum collect the little gems... i mean jets

i have quite a few... i'd need a pic of one if you decide to go up.  i might have some too.  absolutely no guarantees on that one tho.

[ken74-550K0]

I'm also in the process of re-jetting my 74 550.  A very useful resource is motorcyclecarbs.com this link http://www.motorcyclecarbs.com/support_W124.cfm?UserID=78229&jsessionid=7e30763641139112680289 takes you to their support pages.  These pages provide some information I found very helpful when re-jetting.  Additionally, if you call them on the phone - a real person answers - and they are willing to work with you on your carb issues.

As of last October, they did not have any of the push in style jets, they advised me to drill out the set of jets I removed from the carbs when I did the rebuild.  I went from 100 (1mm) to 110 (1.1 mm)) on the main jets and from 38 to 40 for the pilot jets.  In addition to a 4 into 1 exhaust, my bike has velocity stacks instead of the air box.  I am anxious to see how it runs come springtime.

[CharlieVT]

I also have a '74 550 and recently bought some carb rebuild kits from Sirius in Canada.  They also carry main jet tuning kits.  The kit has 2 each of sizes 100, 110, 120 125 and 130 (stock size is 100) ... so you will need two kits at $35 each (Canadian?).  The kit you need is shown in the following link ...

http://www.siriusconinc.com/carb/parts.asp?category=2&supplier=1&id=1

....Otherwise my 550 is in "like-new" condition with only 8K miles (I bought this bike in 1974 and it has been carefully stored for the last 30 years ... 100% stock for now).  

Jim,
Do you realize how many guys wish they still had the bikes they owned in the 70s?  And you did it! Congrats.
Yeah, the stock exhausts didn't last, I am amazed you still have your stock exhaust. I recall mine original CB500 rusted through within a year or two and I went to an after market 4-2. I wish I still had that bike.

I too would put OEM exhaust on my "new" CB550 but they are very pricey and I just can't justify it. Thanks for your post and the link. If  I recall correctly I got something with the 4-1 exhaust from Loud Fast'n Ugly that suggested going two sizes up on the main jets; I regret I can't find that info right now.

I did order a set of jets and will get to fooling around with the carbs when they get here.

Regards,
Charlie

[CharlieVT]

Thanks everyone for all the great info and links in this thread. I did order a jet kit from the CN place. I got a quick email back (personal response, not an automated response) saying they got my order and that the shipment would go out tommorrow.
I read the links on carb tuning with interest; I have tried to avoid changes to stock in my past rebuilds because of the  hassle of re-jetting the carbs, but this just seemed the way to go with the CB550 given the cost of OEM 4-4 mufflers.
Thanks for all the help, I post what I get figured out for jetting to work with my Loud Fast'n Ugly 4-1 exhaust.
Regards,
Charlie

[pablo78cb550]

any luck on the re jetting of your carbs?

[volthause]

for a point of reference, i've got a '74 550 with an aftermarket 4-1 header/megaphone, and individual pod filters. i'm running 110 mains, and it runs rather well.

there is a slight part throttle hiccup on occation while maintaining an engine speed of around 3K5 to 4K5 rpm, but a quick twist of the throttle and it disappears.