Topic: Sluggish 1st Gear Performance / Constant Smoke

[zeech]

Recently acquired a CB550 with a fair amount of cafe work already done to it.

Sluggish 1st Gear Performance
The throttle response in first gear isn't that great. I crank on the throttle to get it to go and it just sort of sits there and takes a while to really kick in and go. This is especially apparent on even slight hills I come to a stop on. I need to get massive RPMs to get it to go otherwise it will be right on the verge of stalling even with the trottle pinned.

I'm running K&N Pods, 4-1 MAC Exhaust and 135 main jets... I thought it had stock jets and was told going to 110s would help, but when I opened up the carbs they all say 135 on them. Seems like maybe too much?


Constant Smoke
The bike sat for about a month after "running great" and I think had an issue with the coi or timing where 1 & 3 weren't firing. Now I get constant light smoke out of my exhaust. I was told it could be a ring that needs to pop back or could be pistons/valves. I'm not really sure.


Any tips would be appreciated, thanks!

[goldarrow]

The jet you have seems to be way rich right off the bat. 

But first make sure you get the manual and go through 3k miles tune up procedure first.

And Welcome.

[Randy]

what do the plugs look like... If there all black ..To rich... I have a 500 with uni pods ..I'm 110 mains and no problem.. Runs better in the mountains of L.A.

[zeech]

Thanks goldenarrow, I'll go through it and do that.

Randy, they are definitely black with a little residue/gunk on them. BTW: Whoa. Just noticed you're in Tujunga, I'm in Sunland.

The 135s that are in there don't have a screw or anything on them so I'm unsure how to remove them and put the 110s in their place...

[iron_worker]

They're press fit. Get some vice grips and firmly pull them out.

If you need to pin the throttle to avoid it from stalling it almost sounds like you're running on 2 or 3 cylinders.

IW

[zeech]

Okay thanks iron_worker I'll do that, wasn't sure and didn't want to damage anything.

It's definitely running on all 4 as all 4 pipes are hot and firing, but again, I think 1 & 3 are the ones causing the smoke. I guess I should really get a compression test done on them. Again, it's only mainly in 1st gear, though 2nd can be a bit jerky sometimes too.

[goldarrow]

what year is your bike? early 550s or late 550s?  the later 550s have screw on type jets I think, the early ones are press in.

don't worry about the compression test just yet.  do the 3k tune up first and see how it runs.  get one of these plug cleaners from HF, sometimes they go on sale for $10 http://www.harborfreight.com/pneumatic-spark-plug-cleaner-32860.html what spark plugs on your bike? ND x22es-u or x24es-u are great, if you have ngk D8EA should be fine, too. 

check list:
-  valve tappet
-  adjust cam chain
- points gap
- ignition timing
- carbs, clean clean and clean, check float heights
- spark plugs

start it up and run and see how it goes

[zeech]

goldarrow — It's a 1974 550. I forget what plugs are in it, I'll check, but thanks for the suggestions as well.

I just had the points and timing adjusted and the carb cleaned and adjusted as well. I will need to do the Valve Tappet and Cam Chain. I'll have to find some info on the vale tappets, can you point me in the right direction?

[Duanob]

135 jets are way too big for those carbs. 110 sounds about right, 100 is OEM with a stock airbox and exhaust. Also check your pilot jets for size they should be 38, maybe 40.

I've attached a couple of how-tos for you. Tappets and cam chain adjustments. Your bike should pull like a bull even at fairly low RPMs.

[iron_worker]

Is your bike a bear to start when cold? Requires a lot of choke and playing with the throttle to keep it running?

Those symptoms as well as really having to feather the clutch out to get it not to bog are all symptoms of plugged idle jets. I would check that as well. You should be able to see light through all passages.

IW

[zeech]

Thanks a bunch Duanob, I will do both of those as well. Appreciate the specifics! I agree that it should pull like a beast even at low RPMs, gotta sort this out. Just ordered some new, push-in 110 jets.

iron_worker — I'm in LA so it's never really cold. I run it every day and it literally starts INSTANTLY when I press the starter. I have had a buggy idle at times; just did a full carb clean and that helped immensely, though the power problems are still there.

Hopefully I can get a handle on this with the smaller 110 jets and a tappet/cam chain adjustment. An oil change wouldn't hurt either I suppose.

[zeech]

So I replaced the jets with the 110s and it still appears to be running rich (plugs black but not as much gunk deposits) — It definitely runs a lot better though and won't max out at 5500.

I think the guy who had this before me had it tuned for racing or something. I'm not familiar with the carbs enough to know how to tune them to run less rich and get the mixture better. Anywhere I can be pointed for some info on this? I'll search around the site as well.

Another issue is after running for a while at 40mph and above when I come to a stop the idle is out of control high and won't really go back down. I've read about this but forget what I can do to fix it.

[zeech]

Calling goldarrow, randy, iron_worker or others. Thanks!

[goldarrow]

your idle high and won't go back down probably cause by carbs boots leak at the intake to engine, and engine to carbs boots.  take the intake ports out and check/replace the rubber orings.  check against parts fiche.  did you check your pilot jets to see what size?  running rich could be at different stages on the throttle, at idle, 1/4 throttle, 1/2 throttle, 3/4 throttle, or at WOT.  you could be running rich at idle, but lean on midrange, etc....  verify your pilot jets size.

these bikes like stock air box, but tuning with pods are do able, but just take time, after time

[zeech]

I will have to check pilot jets etc.

I turned out my air screws to 2.5 and I'm getting a lot better performance as it's not running so rich now. Plugs have far less deposits on them and pretty much no gunk at all, just slightly black.

Now a new problem: It typically starts right up with the electronic starter, but now I have to keep it pressed in while giving it gas and even then it takes a lot of work to even get it going. Once it's running and little warm it idles better than it has. Is this starting issue related to too the mixture not being as rich now? It just doesn't make sense as my plugs are now cleaner than ever.

Battery is fully charged as well.

[bjbuchanan]

Richen the needle and pilot jet. The need for big throttle is because pilot and needle are much too lean. You twist thru it tho and start using that main jet more and then you have acceleration