Topic: 78 550 Idle issues and leaking oil

[l2edken]

Hey guys, first time posting on here, got myself a little project. A 1978 CB550 with a clean title and key, already rebuilt top end. New rings, lapped valves, smoothed ports, pod filters, and a hole filled exhaust. Finally got it running since the first day i bought it but ive got a few issues. First, very strange but i have an oil leak coming from the cam cover end caps. I replaced the o rings on the studs that fit inside the cover but im still getting leaks out of both sides. I noticed that the hole itself is threaded as well. Is there suppose to be a bolt inside of the ports and then the end cap on top of that? Secondly ive got an idle issue. Im guessing that would be my pilot jets being very clogged up as the carbs themselves were disgustingly filled with varnish as it sat for many years. What would be the best way of removing those pilot jets, i know they're pressed in i just don't want to ruin them cause i have yet to see any replacements on any websites. The bike is also pretty hard to start when cold, couple blasts of starting fluid and it jumps right to life but otherwise its almost impossible to start, full choke, quarter throttle, nothing workings unless i use starting fluid. Compression numbers are all good so im not to sure what could be causing that, unless that would also be the pilot jets being clogged.

Any help would be much appreciated, i really wanna get this baby on the road sooner rather then later!

Thanks guys!

[l2edken]

Nobody?

[flybox1]

Just grab those pilot jets with vice grips and pullntwist them out. Get the series of holes along it all cleaned.
Light marring on the outside won't matter, just don't crush them.
What model carbs do you have?

[l2edken]

PD series

[flybox1]

Tear into your accel pump. Probably needs a good cleaning....

[l2edken]

ok, it was the pilot jets, they were completly blocked, gave em a good clean and now she idles real nice. Back to the oil leak though, i believe its coming from the bolt under the end cap, not the end cap seals themselves, where do i go abouts getting the small alumnium washer to seal that up. I just noticed today that the bolt is completly saturated in oil, porbably just running onto the end cap seals leading me to believe it was the orings instead!

[l2edken]

ok fixed my oil leak, accidently had the right side cam cover set up improperly. Once i placed the aluminum washer on the cover and tightened it down, it stopped all the oil leaking. Now this is weird though... Bike runs great, idles great, no smoke or anything so i decided to compression check. left to right: 90,60,30,90... WTF I was getting 120 across the board last week! Im starting to think my harbor freight compression tester is no good! What do you guys think? No way the engine could be running so well with these low numbers... The tester did also go through a flood so it very well might be messed up.

[l2edken]

compression numbers today: left to right > 110/110/90/90 wtf tester?! anyway, oil smelt slightly like gas but was still very viscous, Pulled the plugs and they all looked good though the cylinders seem wet, dunno if its gas or oil but they are wet. No smoke out of the exhaust at all since day one but im still getting blueish/white smoke out of the crankcase. Need to get a clutch cable and bed these rings in i think?

During startup it hunts for idle a little bit and every once and a while will accelerate on its own, like getting bursts of gas, once its heated up though the idle is dead on

Anyone have any thoughts?

[harisuluv]

Might have gotten different numbers if it wasn't warmed up.  Believe you are supposed to warm it up a bit AND you need to have the throttle wide open while cranking.

[l2edken]

both times engine was warmed up and throttle completely open, only difference was one test was yesterday and one was today

[lucky]

Flybox is all over this like a fly on fly paper!  Good man!!!

Idle jets and accelerator pump system cleaning first.
Float levels. All other tuning parts first before the carbs too.
Carbs last.

[l2edken]

PD carbs have a accel pump? cant find anything on them in this PDF:https://s3.amazonaws.com/sohc4/Tech/PD46A_rebuild.pdf Idle jets have been cleaned thoroughly and can be easily blown through and all 8 holes were cleaned. My float heights are spot on at 14.5 mm, double checked again today

[cabrala]

I'll throw in my quick two cents on the carbs. The model #'s change from '77 (PD46A) to '78 (PD46C). Your link to the carb manual is in reference to the '77 550K. From what I have learned over the past months, anything earlier than '77 is interchangeable, while the later two years are different (even from each other). An accelerator pump could have been added to the carbs setup in '78...

I wish I could give you a definitive answer, but hopefully the slight redirection helps.