Topic: Will the airbox effect the idle?

[robdrobd]

I recently looked at a 1975 Cb550f and the the idle was very high/fast. The owner had removed the airbox and had not re-installed it. He said that was the problem. Does that sound right?

[mystic_1]

100% not having an airbox will totally affect you idle.  Install it before changing anything else.

mystic_1

[tortelvis]

Any time you change the stock setup there is a consequence. It will certainly affect running by removing the airbox. Tell him to put it back on so you see how it runs then. Many times I have looked at a prospective purchase and been told similar things. "It just needs a tune up...it just needs a $3 part to make it run perfect...I can't let you test ride it because there is no insurance, etc".

[robdrobd]

I thought it probably would cause idel problems. The bike had very little rust, all working lights, and ran strong (other than the idle) so I bought it anyway. ($350.) I know this is a pain, but can someone post the link for a high quality service manual for the 75' 550f? I've seen it on the forum before, but now all I can find is the jpg. one, or the low quality one on the "Italian" website Honda4fun. I would prefer a pdf of the whole thing. Thanks a bunch.

ps- I hear the airbox can be a pain to put on. I hope this is just a myth!

[mlinder]

These are all legit sohc questions, you shoul dbe posting them in the main forum. You'll get mor ehelp that way.
Yes, putting on airboxes can be a tad troublesome at times.

[tramp]

whenever i hear those cheap fixes i ask why they didn't do them and ask more money for the bike

[edbikerii]

Nope, sounds like BS to me.  I would be very mistrustful of a seller telling you that.

I removed and replaced my airbox and pods several times, and it never made much of a change at idle at all.  In fact, when I was done jetting for pods, the pilot jets remained stock.  See the thread in my sig below.

Did you ever hear of a car idling poorly when you removed the air cleaner?  I never have.

In fact, possibly the only issue I had with pods, once rejetted properly, was that the bike was a little hard to start when ambient temps were below 40F.  I had to leave the choke on longer when temps were <40F, too.

I've got to agree with tramp, if this were the only problem, why wouldn't they just put it back on and ask for more money?  Also, why did the seller take it off in the first place?

[mystic_1]

75 550F = CV carbs?

mystic_1

[myhondas]

And as it has been shown, the stock airbox is one of the very best setups for the bike. Pods have a lot of problems. Earlier airboxes in the 750 K0 & K1 had larger openings and helped create more power than the later models.

[TwoTired]

I recently looked at a 1975 Cb550f and the the idle was very high/fast. The owner had removed the airbox and had not re-installed it. He said that was the problem. Does that sound right?

No.  It's seller BS.  Be prepared to overhaul the carbs.  Most likely the slow jets (at least) are plugged up.  Or, he already had the carbs off and fudged them up, then decided to sell off the problem(s) rather than work on it some more.

Now this does mean an idle higher than 2500RPM.  "Very High" might mean something different to you.

He probably had no clue how to remove the carbs with the air box on.  Better check the aft couplers for damage.

Do a search for 550 carb installation for a working procedure.  It's not particularly hard unless you do it the wrong way.