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Anglia4's CB650


anglia4

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Guest Hayholes mum

I don't know anything about your bike, but I had a slight misfire once on no3 cylinder and it caused unburnt fuel and a bit of oil to spill out exhaust flange and onto engine fins... Looked just like a blown head gasket.

Turned out to be coil issue!

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Guest kicker

I don't know anything about your bike, but I had a slight misfire once on no3 cylinder and it caused unburnt fuel and a bit of oil to spill out exhaust flange and onto engine fins... Looked just like a blown head gasket.

Turned out to be coil issue!

Good to know, I'm chasing a similar issue, was your coil still sparking on both cylinders and was just weak?

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Guest Hayholes mum

Initially I had an issue with cheap aftermarket points that were jumping round at high rpm ( points don't like high rpm at all)

Then went to electronic ignition but existing coils couldn't handle the load. All 4 cylinders still had spark, but must have been breaking down at high rpm.

My theory is that on an old air cooled engine when a cylinder is misfiring a little bit of oil sneaks past the rings due to the suction caused by a lack of combustion therefore mixing with the unburnt fuel fouling up the plug etc etc.

I don't really know shit about anything... This is just a theory in my head!

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  • 2 weeks later...
Guest anglia4

Took it through for a WOF yesterday.

Failed on:

  • No Reflector
  • Missing split pin from rear axle
  • viewing angles of tail light
  • no silencer of mufflers

Some pain in the ass items on that list.

I made up some inserts for the pipes last night which will hopefully get it through, the guy even said, "It really isn't too loud, but the rule in the book says it must have some muffler or silencer" PITA!

I think I will just make an extra bracket to raise the tail light up for the WOF and might make some really small reflectors to hide under my indicators.

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Guest kicker

The last two bikes I revinned were failed on not having a reflector, pain in the ass, I just used one off a bicycle then took it off afterwards

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Guest anglia4

I bought a compression tester last week, turns out it doesn't come with the right fitting for my little plugs :(

Pulled the plugs anyway to check the tuning, looks like its running a little lean. One cylinder was carboned up quite bad so might have a bad lead or something.

Seems to be oil everywhere too, really over this engine, just wish it would run properly!

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I often get headgaskets weaping oil on lawnmowers a couple days after replacing them. what I do is tighten up the bolts to like 20 ft lb instead of like 15 and then its usualy sweet. aircooled is weird it like weeps oil out even when the gasket is fine

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Guest anglia4

Yeah am thinking I'll re-torque when I get back from nats.

The head bolts are a real mongrel to get to. Have to take off the cam and rockers etc to get at them.

If it still leaks after that then I'll order more new gaskets and pull the head again and check it for warpage :S

When I put it together last night I put the carboned plug in a different cylinder so I can rule out a faulty plug as the cause of that (they are all new). If its not the plug I'll replace the lead. and beyond that I have no idea. Also might pull the carbs and lift the needle to give it a bit more gas.

I'm liking the way it sounds with my restrictors in the exhausts so I might make some proper baffles for it, to make it sound a little nicer. Sounds more like a bike and less like a tractor.

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Are the carbs balanced properly?

Before lifting needle maby check to see that that carb isn't more closed than the others?

Check yo needle valves too. This can cause fowling of plugs etc.

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arse.

Are you running bigger jets than factory? you not running factory airbox eh

(sorry, i should go back and read what you have done... hah)

Edit: pod filters i see.

Mine fouls plugs if i let it overrun too long, at too high revs.

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Guest anglia4

I can see its running a little lean by the colour of the plugs, but just one is carboned up. So i don't think its just tuning, I think its more likely poor compression or an ignition fault on that cylinder.

Yeah much bigger jets than standard. (copied what someone on the net had done for pods and aftermarket exhaust)

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