Cb350s burning oil

[rob_scott92]

hey guys,

After riding the 350 for a couple of months, i've had a little problem regarding oil.
It is definately burning oil, i know that, but its getting to the point where i'm actually a little worried about it. Its only got a small dipstick and to check the oil it says in the manual to run the engine for a minute, turn it off, let it settle and then check the level without screwing the dipstick in. The thing that worries me is that with the slightest difference of angle change (Flat surface or leaning very slightly to the right) the level shows full to not even touching the end of the dipstick.
Its got to the point where i'm topping it up every couple of days, i think in 3 months i've gone through 2 litres + just topping it up

I understand it could be more than one thing doing this, it has got 45K miles on it too.
Valve seats, valves and piston rings. Anything else to consider? and anyone got any experience doing these things on the cb350s or similar (250 superdream???) Finding parts could be an issue and finding money even harder.
Would using a thicker oil burn less? Its got proper 10w40 motorcycle oil in at the moment.

any help appreciated
Rob
____________________
First bike: 1982 Suzuki Gs 125 'The beast MK1' > 1988 Honda Cb 350's' FOR SPORT! (Good ol' oil burner!) > 2001 Suzuki Sv 650 's' Made it out of the 80's! > 1997 Honda Cbr 600f :p

[Frost]

Thicker oil will burn slower. Valves and valve seats won't cause oil to burn, stem seals & rings will. Run it for a bit and see if anything leaks out when its warm.

You can normally see and smell if oil consumption is a problem, if not just keep topping it up and using it. i have a superdream that used to chug a fair bit of oil, always ran fine though.

[Robby]

Depending on how much you want to get stuck in, stem seals normally come in a pattern gasket set, which is about £25. This means you can strip the top end, check the ring end gap, regrind the valves and fit new stem seals.

The only problem is that the camchain may run between the cylinders, which can make it more difficult to dismantle.

[rob_scott92]

[rob_scott92]

Also gaskets! There arent any on ebay or wemoto which means i'll have to go to a bike shop to get them A little expensive i imagine
____________________
First bike: 1982 Suzuki Gs 125 'The beast MK1' > 1988 Honda Cb 350's' FOR SPORT! (Good ol' oil burner!) > 2001 Suzuki Sv 650 's' Made it out of the 80's! > 1997 Honda Cbr 600f :p

[N cee thirty]

david silvers ?
____________________
'00 Aprilia RS50 > '92 Honda CG > '99 Yamaha Fazer > '91 Yamaha RXS > '79 Suzuki X5 > 01' Honda Cg > 07' Honda Cg > 82' Kawasaki Z200 > suzuki gsxr 400 gk73a > honda vfr 400 NC30 Mod 2 Passed 09/06/2011

Jewlio Iglesias wrote: I actually did vote BNP once

[rob_scott92]

[rob_scott92]

No gaskets whatsoever although there are quite a selection of spares on there, just no gaskets
____________________
First bike: 1982 Suzuki Gs 125 'The beast MK1' > 1988 Honda Cb 350's' FOR SPORT! (Good ol' oil burner!) > 2001 Suzuki Sv 650 's' Made it out of the 80's! > 1997 Honda Cbr 600f :p

[radical]

To save on gaskets you could change your valve stem oil seals ( there are six) without removing the head from the engine and see if that cures the problem first, failing that it is going to be the piston rings and /or cylinder bore.

[Moo.]

Wont he need a valve compressor to the the circlips off for that?
____________________
A2 Passed 18/6/10

[radical]

No, they are split collet which can be removed by pressing a ring spanner on the spring cap but you need to tie up each valve incase they drop down, its a lot easier to do with the head removed but if you cant find a head gasket then it can be done this way.

[smegballs]

[Kickstart]

Hi

Do a compression check, both wet and dry to get some idea about the rings.

There are tricks to doing the valve stem oil seats without taking the head off. Bodge job is to feed rope through the plug hole into the cylinder, the turn the crank to wedge the valves closed with the string (make sure you do it in such a way that both valves are closed) and then you should be able to slightly compress the valve spring and remove the collets. A more professional method is to connect a supply of compressed air to the plug hole and use that pressure to hold the valves closed.

The Superdream engine does have a central cam chain.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[Kickstart]

Hi

Oh, almost forgot. Selenia do a (car) oil designed for older engines to cut down oil use. It is a 20W60 fully synthetic.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[radical]

[Kickstart]

[rob_scott92]

[Robby]

The camchain runs from the crankshaft to the camshaft. If you take off the rocker cover (top cover on the cylinder head) you'll be able to see it.

The balancer chain (if you have a balancer, you probably do) runs from the crankshaft to the balancer shaft(s). These bits are all in the bottom end.

The balancer chain is rarely replaced, it has less load to deal with and runs in a better oil supply. Cam chains do occasionally need replacing, but only after a very long time (100k miles plus on vaguely well maintained bike). I'm replacing one at the moment, but only because I doing a full engine strip and rebuild. The chain has done 30k (on the clocks, which may be lieing) and 30 years and still looks new. Tensioners tend to give up more regularly than cam chains.

If you do decide to strip the engine, there may be a way to get the cam chain out without splitting it. If the cam chain sprocket bolts onto the camshaft, they it can probably be unbolted and slid sideways to drop down half an inch or so. This, combined with removing the tensioner, may be enough to slide the camshaft out from under the chain.

[Kickstart]

[fiery tupp]

[Frost]

for Granby. I needed some gearbox gears for an import SRX 600, chances of me finding them were never going to be good... Granby had them in the post for the next day, seriously top blokes

[Kickstart]

Hi

Another vote for Granbys. They were quick and helpful at sorting out a few spares for my import TZR250.

All the best

Keith
____________________
Traxpics, track day and racing photographs - Bimota Forum - Bike performance / thrust graphs for choosing gearing

[rob_scott92]

Wow thanks for the detailed reply robby Very helpful here, have a cookie

Thanks for the links also, i shall take a look at them as finding any parts for this bike could prove difficult.

Just one last thing though, Cam chains need adjusing every so often right? (Thats what kinda started all this off ) How do i adjust it??? Are there some that are self adjusting? as i said before, theres no mention of the cam chain at all in the manual. Can anyone shed light on this? I could scan part of the manual if that'd help.
Thanks again
____________________
First bike: 1982 Suzuki Gs 125 'The beast MK1' > 1988 Honda Cb 350's' FOR SPORT! (Good ol' oil burner!) > 2001 Suzuki Sv 650 's' Made it out of the 80's! > 1997 Honda Cbr 600f :p

[rob_scott92]

Also,

[Kickstart]