Cb600 rebuild starting issues

Malt_Vinegar · 6 Dec 2020 at 16:39

Weak starter motor, or perhaps a low battery?

Scuzi · 6 Dec 2020 at 17:20

What do the spark plugs look like? If it is starting cold without choke it points to a mixture issue. Do the plugs look like it’s running rich?

slim01 · 6 Dec 2020 at 17:31

Malt_Vinegar said:
Weak starter motor, or perhaps a low battery?

Battery is literally brand new motobatt, and cranks and cranks more than I'd even expect it to. Haven't even seen it go flat yet which is crazy as sometimes it's been cranking for a total of at least 5 minutes.

Is a bad starter motor symptom not starting when cold but starts OK when warm then?

I'm not even sure what I can rule out at the mo.

Getting sick of new things costing me. New radiator and hoses is like £200 alone. That's just this week!
Seriously thinking of cutting my losses and selling as a non runner. Bought for 770, now in total its cost me about 1500. Be lucky to get back 700 as a non runner I guess though.

slim01 · 6 Dec 2020 at 17:33

Scuzi said:
What do the spark plugs look like? If it is starting cold without choke it points to a mixture issue. Do the plugs look like it’s running rich?

Spark plugs are brand new so hard to say... They look new.

slim01 · 6 Dec 2020 at 17:35

Having said that they've had a few miles now, maybe around 150 since last checked, is that long enough to diagnose anything?

MatteH Oxford · 6 Dec 2020 at 17:36

slim01 said:
Update...

Bump starts instantly.

Is pretty much fine except when cold starting.

Not sure if that means anything to anyone.

Are you sure the starter is (always) actually turning the engine over? It sounds silly but remove the clutch cover plug thingy in the middle of the clutch housing (if it has one) and see if the engine is actually rotating under the starter. Be careful of oil leakage.

slim01 · 6 Dec 2020 at 17:44

MatteH Oxford said:
Are you sure the starter is (always) actually turning the engine over? It sounds silly but remove the clutch cover plug thingy in the middle of the clutch housing (if it has one) and see if the engine is actually rotating under the starter. Be careful of oil leakage.

I have no idea. Sounds OK... But I'm confused... If I take the clutch cover off yeah they'll be oil everywhere and clutch wouldn't work... The cable that goes into the clutch cover is just the clutch cable I think.

MatteH Oxford · 6 Dec 2020 at 17:48

slim01 said:
I have no idea. Sounds OK... But I'm confused... If I take the clutch cover off yeah they'll be oil everywhere and clutch wouldn't work... The cable that goes into the clutch cover is just the clutch cable I think.

There's often a screw in plug right in the middle of the whole clutch cover housing, it's removable to allow easy access to the crank bolt so the engine can be rotated manually.
It may be on the other side of the bike on the crankcase cover, I don't know cb600s well?

like this:

slim01 · 6 Dec 2020 at 18:37

MatteH Oxford said:
There's often a screw in plug right in the middle of the whole clutch cover housing, it's removable to allow easy access to the crank bolt so the engine can be rotated manually.
It may be on the other side of the bike on the crankcase cover, I don't know cb600s well?

like this:

Well this is the cb600 (2000)... Can't see one on the clutch case here.
I guess I don't have that?

https://images.app.goo.gl/9KW1jcQsqCeU3Xpm9

Scuzi · 6 Dec 2020 at 20:22

slim01 said:
Having said that they've had a few miles now, maybe around 150 since last checked, is that long enough to diagnose anything?

If it’s running rich you should be able to spot it by now.

manius · 6 Dec 2020 at 22:47

have you checked the choke slide on the carbs you can catch this when you put the tank back on and bend it so its not as free moving as it should be can cause running issues and some times it will be ok other times it will stick causing bogging down happened to me once after i had cleaned my carbs

also do you have any pics of the bike ??