Re jetting CB550 with pods - questions .

[Shooter]

Now my bike is back on the road (and I have done 250kms of test riding on it) I have figured it needs re jetting to cope with the pod set up (as pictured).

How does one figure what jets to install - is it trial and error or is there a "formula" or trick?

Fueling seems fine up to 4000rpm then cracks up a bit through to 5000rpm ish. Effect is most noticable under load of hill. Feels generally like I need to keeping winding on some throttle at speeds of 55-60mph (95-120Kph)

Can anyone suggest what jets to try?

Bike starts and idles easily. With non agressive, easy throttling, engine is smooth and responsive at urban speeds.

 

[HerrDeacon]

I don't think there are any hard and fast rules but there are some things you can do to estimate a good starting point. This page gives some recommendations based on modifications done like pods, exhaust, etc. It should give you a good idea.

Also, are you on any good CB forums? Usually there are others who have made the same mods that should be able to tell you what they are using.

Best of luck.

 

[locOleoN]

What kind of exhaust are you running? Stock?
I could be wrong but it sounds like you are getting to much air at higher RPMs
But them mabe you should open up the exhaust a bit?

 

[Shooter]

I used 25% larger jets on my CB550F when I went to pod air filters. The bike runs well through all ranges and the plugs are the correct color.

I think that jets have a # number : I wonder what # a stock jet would be ? ( what I presume is running at the moment. )

From that I need to know what # would be 25% bigger. I have seen the jets for sale on http://www.siriusconinc.com/default.asp

Anyone know of a table that shows this info I need to work this all out.

Noel - I am running a custom built 4 into 1 exhaust sytem.

 

[swan]

I checked my CB550F and I am running #112 main jets (98 are stock) with a 4-into-1 exhaust and foam Uni filters. They were $3.95 each from speedmotoco. I hope this helps.

 

[Shooter]

I checked my CB550F and I am running #112 main jets (98 are stock) with a 4-into-1 exhaust and foam Uni filters. They were $3.95 each from speedmotoco. I hope this helps.

Perfect thank you swan - that gives me the info I need and I will try them as well.

Did you install them your self and was it dificult? ( I have never done carb work at that level)

 

[swan]

Like everything else, it is easy if you now how. Take the time to learn how to do it yourself.

Drain and pull your carbs. Open them up one at a time, clean thoroughly, slide the float stopper off, pull the main jet, clean again and replace with new. If your carbs are off, clean, clean and clean and also reset to the proper float height to avoid problems in the future. Any decent manual has instructions and check this and other sites for instruction to rebuild carbs.

Good luck and post your results.

 

[Shooter]

The carbs were sorted by a professional before I put the engine back in. They had new carb kits etc installed and were balanced up.

I now know where the jets are located (I had some other Cb550 carbs on the bench today) and hope fully I can do the job without pulling the carbs from the engine. Will do so if neccessary or someone tells me its the only way.

I am feeling a bit more confident about doing it myself (once I locate the new replacement jets)

 

[renegadmonk]

Now my bike is back on the road (and I have done 250kms of test riding on it) I have figured it needs re jetting to cope with the pod set up (as pictured).

How does one figure what jets to install - is it trial and error or is there a "formula" or trick?

Fueling seems fine up to 4000rpm then cracks up a bit through to 5000rpm ish. Effect is most noticable under load of hill. Feels generally like I need to keeping winding on some throttle at speeds of 55-60mph (95-120Kph)

Can anyone suggest what jets to try?

Bike starts and idles easily. With non agressive, easy throttling, engine is smooth and responsive at urban speeds.

where did you get those...will put some on my 450

 

[Shooter]

I am in NZ so that may not help you.

They are fairly common and you just need to know the size of the Carb inlet.

I have seen them on EBAY if that helps.

 

[TonUpSoldier]

Shooter, the best i can tell you based on my limited experience as far as jetting goes would be, since you are running a 4into1 pipe (add two sizes up) and pods (add 5 to 7.5 sizes up) Needles, if adjustable in those carbs, would need moved up one slot from stock (ie, if your needles have slots in them and are adjustable, and stock is the third slot from the top of the needle, it would need to be moved to the 4th slot) this is, however, guesstimation.

 

[Shooter]

This bike always was 4 into 1 although now it is into a Custom 4 into 1 that I think would be close to the original.

Thanx for tips - they all help. Thought I would try the 112 jets first then take it from there. I could get lucky and not have to mess with needles. Hope fully they arent even adjustable.

Nice thing about injected bikes...you throw them on a dyno and you chuck in a Power Commander and bingo ...job done. ($$$$$$$ but easy)

 

[Shooter]

Job done ;D

I fitted #110 jets and the improvement is significant. (Original jets I discovered were #100s)

Engine revs freely especially under load and does not need the long warm up time.

Who would have thought that such a tiny device with such tiny holes can make that much difference.

I guess I just need to keep an eye on the plug coloration for a while now.

 

[Blake]

Jet chart:

http://forums.sohc4.net/index.php?topic=58112.0