Cbr600 2002 Engine wont idle/run when warm

[sickpup]

[Pete.]

My GS550 had a slightly bent valve and you could see the head tilt every time it seated. I had to change the valve though, I just imagined that after tens of thousands of cycles it would eventually let go at the neck.

BTW there's no such thing as 360 degrees and 2 teeth out on a wasted spark engine. It's either 2 teeth or not 2 teeth.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[kramdra]

I would like to know, ignoring the cam and crank index marks... At what position should a cam lobe be for a clearance check? Is it the point of maximum clearance?

Mine were all on the semi circular half of the lobe but in various positions. Most with the lobe horizontal some with the lobe slightly up
I realise this is irrelivant as it has all been worked out for me with the marks, but I would like to know. I would have assumed pointing straight up, other than the bottom 6th of the lobe is only 1 third of the width and may be why. They all seemed to be on the full thickness bit.

[Pete.]

IIRC valves are closest to the piston at roughly 10 degrees before and 10 degrees after TDC.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[kramdra]

Ok last question for today

https://i.postimg.cc/vTb2mgy4/IMG-20200525-182459.jpg

To me these look and feel like cracks. Its common for cam bearing caps or camshafts to crack if tightened incorrectly? I remember the noise made by the cam bolts on my other engines as they were loosened off. A lot of stress there.

As only a couple of shims are 5-10 microns out, less than a blond one, should I leave it as is, or try to change the shims?

Bearing cap will be line bored to the head, its not a replaceable part so if its not servicable then the head/engine, will be scrap.

[sickpup]

[Nobby the Bastard]

You should be measuring the clearence when the lobe of each valve is completely opposite the bucket.

I'm inclined to think that you dont know how to use feeler gauges judging by your previous posts on this thread so here goes....


Find the one which goes in with absolutely no friction between cam and bucket and the work up slowly. If you have to put more.than minimal effort in you are probably pushing the valve down.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[kramdra]

The book and the engine are like this.

https://i.postimg.cc/NF8v09zV/IMG-20200525-200549.jpg

[Nobby the Bastard]

[kramdra]

The position of the lobes for measuring number 1 intake.

I had camera down the bores last week. There are no valve marks. 1, 2 and 3 have thick carbon piston crown deposits. 4 is shiny and cratered like the moon from helicoil swarf, but no valve marks, so the valves are not bent.

No comments yet on the bearing cap cracks?

[Nobby the Bastard]

That is the position for measuring the intake and the exhaust without moving the crank/cams. I tend to do whichever valves can be measured in a given position on the cam and then move onto the next set.
That's the difference between following instructions in a book and understanding why they were written that way.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050

[Pete.]

Most bikes of that ilk with their symmetrical cams will be at 10 and 2 o'clock on TDC on the firing stroke. Since the followers are on the base cam base circle it's safe to check the valves that way.

'Cracks' look like normal casting flash marks to me. Nowt to worry about, a feature of the investment casting process.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Hong Kong Phooey]

[kramdra]

[Fizzer Thou]

That piece of metal that has been floating around inside the cam cover area looks like the top cam chain tensioner guide that is there to stop the chain flapping around

https://i.postimg.cc/B6pPW8qr/IMG-20200522-190333.jpg

Fowlers of Bristol appear to have them in stock (as well as the rear tensioner guide blade).Not parts very easily made.

https://www.fowlersparts.co.uk/parts/4831060/cbr600f1-2001-e/cam-chaintensioner

As for the cam chain tensioner blade that you are contemplating purchasing from Dave Silvers,all that they would do is to buy it from a main dealer like Fowlers of Bristol.Better to buy direct.

The beauty of having the cam chain at one side of the engine is that it is a lot easier to replace once you have removed the chain from the cam sprockets.On my 5JJ-R1 I can remove the chain from the crankshaft once the tensioner has been removed.It is then easily lifted out and the new one dropped down through the chain tunnel.

I would be replacing the cam chain at the mileage that the engine has done.Although an OEM chain is £78 from Fowlers.

It seems that exactly the same chain is available from the likes of Wemoto.The fact that it states that a rivet link is available suggests it can be done differently to how it can be done on my R1

https://www.wemoto.com/bikes/honda/cbr_600_f1/01/picture/cam_timing_chain_borgwarner

At least the shims are relatively cheap at around £5/shim

https://www.wemoto.com/bikes/honda/cbr_600_f1/01/picture/valve_shim_1.40_mm

Do not forget to replace the cam cover seal

https://www.fowlersparts.co.uk/parts/view/12391MBWJ20

It all adds up but it is a good idea to do it with the right parts.I would not think that it would be that worthwhile contemplating making your own shims to the sort of accuracy required for what you need.
____________________
Just talk bikes.What else is there?

Always have a 'Plan B'

[kramdra]

The book wants a sealant for the semi circle gasket areas. Ive used Hylomar blue before by the tube is dried up now. Looks like dealer used grey RTV last time.
What should I get? It will only be used where the book specifies, along side new gaskets

www.ebay.co.uk/itm/Hylomar-Universal-Blue-Gasket-Jointing-Compound-Sealant-40g-Fuel-Resistant/123553195465
www.ebay.co.uk/itm/Hylomar-Hylosil-Instant-Gasket-40ml-Tube-RTV-Silicone-Sealant-Free-Postage/333513722489

The front and rear chain guides dont appear worn.

DSS are same price as dealers and in my experience they are better to deal with.

[Hong Kong Phooey]

[kramdra]

Thanks.

As I said earlier its about 12 years since Ive pissed inside a proper engine. Ive got the cam bolts out but it is not free and does not pull free. Before I grab my angle wedges and gently tap it out, is there anything I have missed?
The book mentions dowel pins, so it needs to come off straight.

https://i.postimg.cc/ZRhm8mxY/IMG-20200527-155530.jpg

Two remaining bolts are in blind holes.

Edit - seems stuck on a dowel pin in the center at no.1 end. It is now off.

[Hong Kong Phooey]

Don't drop them shims

Make sure to torque it back up and follow the tightening pattern.
If you don't, you won't get the clearances you calculated for.

Recommend you buy shims they're case hardened for this application.
____________________
'81 CG125, '97 FZS600 : '99 CBR600F4, '09 KTM RC8

[kramdra]

https://i.postimg.cc/MHMbHmFK/IMG-20200527-172802.jpg

https://i.postimg.cc/YCwZcvvm/IMG-20200527-180117.jpg


No sign of the chain guide plastic. Its not in the chain tunnel or in the clutch cover. No visible wear on the side guides.
https://i.postimg.cc/g0GvPWyD/IMG-20200527-172103.jpg

Appears zero wear on the cam lobes

[kramdra]

I have mapped out the shims, I have a few to cut down and one I need to make up as the remaining spare is too small.

Sizes needed
1.81, 1.93, 1.97, 1.98, 2.02

Spares
1.85, 1.90, 1.95 , 2.00 , 2.10

[Pete.]

The 1.90 and 1.95 will be fine. They are only 1 thou under your target. Too loose is ok, it's too tight you want to avoid.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[kramdra]

Something I noticed at the start and ignored, the shims have a recessed step in the center where it sits on the valve. They all have it, so not improtant for the shims I shuffle round. The center step is smaller than a normal mic head, so I can expect my readings to all be a thou oversize.

I have cut the first shim.
https://i.postimg.cc/k5DP9B7n/IMG-20200529-224505.jpg

[Pete.]

They are not supposed to have a recessed step, so make sure you're measuring from the bottom of the recess when you take the thickness measurements. If your measuring tool didn't manage that first time round (which you say it didn't) then you're going to have to turn off the OTHER side of the shim or none of your measuring work so far will count.

You'll also need to make sure that the shims go back in with the recess against the valve otherwise your clearances will close up by the depth of the recess. actually, this might be a way to get over your 'too thin' shim problem.

If this were me I would re-fit all of the shims inverted and start all my measuring again.
____________________
a.k.a 'Geri'

132.9mph off and walked away. Gear is good, gear is good, gear is very very good

[Nobby the Bastard]

I cant speak for this model but fz shims have a recessed step when new and are designed to sit snugly onto a button on the top of the valve.
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Sprint ST 1050