Honda-SOHC

Hi guys,

A while back I made a post about the issue i was having selecting first gear, seen here

http://www.sohc.co.uk/index.php/topic,9195.msg63727.html#msg63727

I've only just gotten round to taking a look at the bike (bad I know), anyway I removed the clutch cover and found a chunk of alloy laying in the bottom, removed the clutch assembly and upon closer inspection have found part of the lower casing has 'chipped' off around the gear shaft plug at the end.

I made a post on a CB550 facebook page and one guy in particular had also had this issue with gear selection and described the exact same culprit being a cracked part of the casing in the same place. The bit thats missing was retaining the shaft meaning there was no endfloat, however now the casing has cracked it means the shaft can move in sideways axis approx 3mm and this causes gear selection issues.

Stole this picture from the internet to show you guys the bit i mean, this is what i should look like:




And this is mine!:




Has anyone else ever had this issue? If so how did you go about fixing it? The guy on facebook didnt have any reference pics but said he'd tapped the casing with M6 threads, made a plate/bracket up and put shims behind the retain the shaft.

Before i have a go at it, i was wondering if anyone on here had seen it before and knew of any alternative solutions?


Thanks in advance!

Rich

Hi,

Having issues with my 550 not engaging first gear properly and making some pretty interesting noises. Brief history of recent events:

- Was riding fine, clutch cable hopped out of bracket by clutch housing due to loose locknut
 
- Re-fitted cable and adjusted to suit
 
- Rode fine for about a day, then sometimes wouldnt take off in first gear (gear engaged, clutch out, revving free, then sometimes would bite and take off). Other gears fine

- Decided clutch plates possibly sticking, fitted new clutch pack and cleaned up slightly corroded steel plates
 
- Fresh oil with new clutch install
 
- Rode fine for around 20 miles, then same issue started again
 
- Started making strange rattling noise when engaging first, sometimes wont engage at all, sometimes does, but then rattles again with clutch released.

All other gears are fine and clutch doesnt slip throughout any gear at any revs. Been pulling away in 2nd to get it home.

I took this video to show you, rattles into first gear, start releasing clutch, rattle comes back:

https://youtu.be/y3jD9-GKxuI


It appears the rattling noise and vibrations are coming from the gear selector spindle or something related. Quite certain its not the clutch. Could it be the gear itself, or the selector mechanism??

Any pointers appreciated, its my first time owning a bike like this and ive not taken the engine apart yet!

Thanks

^^ Good to know! Hopefully no issues for a while now

Guys just a quick question instead of starting a new thread, im having clutch issues. With the clutch fully released while stationary in first gear , bike goes nowhere when reving, all of a sudden theres a "clunk" and the bike takes off. Sticking clutch plates?

Oil is fresh and at a good level, clutch adjusted correctly.

Took the cover off and saw this:



Does this look normal? Looks like theres quite a large gap between the friction plates, in comparison to pictures of other 550' clutches ive seen?

Not had time to take the clutch off and inspect due to losing my circlip pliers!

Thanks for the input guys!

Ignition fault would be my first thought, so check the condition and security of the points, the condensors and all the wiring leading from them. Some Honda fours, 550's I think were prone to the yellow and blue wires working loose where the snap connectors join in the rubber shield near the back brake pedal.

Points look to be in nice shape, no pitting or grime etc. All the connections are secure and appear in good nick too, i checked at the connections you mentioned up behind the brake/frame and theyre solid and clean.

If its a 78K with PD carb and starts without choke then the carbs just aint set right

Thats what i thought! I have the screws set 2.5 turns out, too much? Mains are 110, stock idle jet, stock needle position, new clean pods and an open exhaust.

check the resistor plug caps,

 they normally have 5k resistance,but over time,when hot ,they fail,

I had one go 10 days ago,new cap,smooth as silk again ( I hope,well it run sweetly now)

does anyone understand electricity and resistance?

 with electronic ignition,I get a FAT BIG spark,so I run 33thou plug gap,how does 5K resistor plug caps affect them,would the bigger gap
cause the cap to fail sooner ??

Checked the caps and they're all 5k ohm which appears to be right.

I does sound like an ignition problem.   There's two separate, independent ignition systems, one firing 1 and 4 and the other firing 2 and 3.
Try to determine which by feeling the temperatures of the header pipes.
What ignition set up have you got;  is it the original points or have you gone electronic?

Im pretty sure after the other evenings ride it was 2 and 3 that were down, as when i pulled the plugs they were really sooted up in comparison to 1 and 4. This was making me think ignition/coil/points etc too.

It's the stock points system, but could possibly be made up of after market non-genuine bits.

Ignition related I am sure from the pair of cylinders going like that - assuming the filters have had a similar life ( possible for outside pair to get more weather , maybe washing out any oil etc, depends on the pod filter type. I have had issues in the past with condensors malfunctioning when hot ( belive it was that, I described the symptoms to a collage mechanics tutor who recommended chainging the condensors and this seemed to resolve it.

The filters are brand new UNI pods which i know a fair amount of people use on these bikes without issues, the condensors definitely dont look new on this bike so could potentially be an issue.

I agree.  I rode home 70 miles on my 400four going like a 200two.   I was just a dodgy capacitor.

70 miles is impressive! haha


Well, this morning i checked the plug caps and snipped the leads back a couple of mm's even though they looked good. I went for a 1 hour ride with a spare plug in my pocket, so if i started running on two i could check to find where the loss of spark was.

I suppose its a good thing that the bike ran faultless the whole time?! I tried a few WOT pulls aswell and it was fine. Although the clutch cable snapped and i had to ride back through the gears without stopping, good fun!

I rode it to its MOT on wednesday night and it was pouring with rain, a friend of mine said he had a few issues in the wet with cylinders 2 + 3 going down due to being soaked from the front wheel with no mudguard (i dont have a front mudguard either). This sounds possible, but is kind of weird that when i rode it the next day in the dry it was fine up until it got hot?


Heres the ignition



Thanks again!

Rich

Ahh ok interesting thanks for the insight, I plan to have a different seat all together so it wouldnt matter in the long run, the standard seat will stay on there for now though. Quite like the raised fuel filler of the US tank then!

Hi all,

As title, do earlier model tanks (ones without flush fuel caps) fit late model 550's? Im after a replacement tank as is stripped mine down to find a patch of filler hiding a big dent, its also rusted through and leaking.






 

Changed a cracked sump on my recently purchased 78' CB550K, so drained the oil and didnt see anything worrying in there. Replaced sump, decided to change the oil filter for good measure.

Removed the oil filer housing from the front of the engine to find the remaining oil thats in there has a fair amount of fine gold (i guess brass), flakes in it.

What could this be from? Im pretty concerned now as i just want to use the bike but have a feeling i'll need to tear the engine down now..

The bike has 54k miles on it, unsure if the engines ever been rebuilt. History from previous owner includes a new primary chain and replacement top end..