Checking Camel timing at 6k rpm

[fofs216]

Hey Folks,
My cam belt let go on my Camel mk1 at the weekend, fingers crossed there isn’t any damage!
I’ve ordered a new belt, flywheel pulley etc to hopefully sort but I also wanted to check the timing.
The book says to check at 6000rpm but the mk1s don’t have a revcounter! Is there a way of knowing I’m at 6k rpm without one?
I can only think of running in gear and judging a particular gear against an indicated road speed with the rear spinning but i’m hoping there’s a simpler and safer way perhaps!
Many thanks in advance,
Jamie

[norbert]

Have a look at the pushrods for the rocker arms. Sometimes they are bended after a teared belt (usual with 350 motors). With 500 motors more often exist the posibility of a bended valve (this happend to me at 7000 revs in 6. gear with a 501 motor). Of cause I lighted a candle for our genious Lambertini! Loosing all times at 7000 revs and only one valve to change, that real great!!!!!

norbert

[fofs216]

Hi Norbet,

Thank you I'll check the rods, fingers crossed everythings ok!!!

Best,
Jamie

[Steve Brown]

As said by Norbert, go over the valve clearances. It happened on a Camel of mine years ago and did bend a valve ever so slightly. It ran poorly but obviously had to be replaced.
As for the timing check, just rev it high and check it stops advancing when it gets to the ANT1 mark. Or if you want to check the revs borrow an automotive multimeter with an RPM lead that clamps onto your HT lead.

[72degrees]

As said by Norbert, go over the valve clearances. It happened on a Camel of mine years ago and did bend a valve ever so slightly. It ran poorly but obviously had to be replaced.
As for the timing check, just rev it high and check it stops advancing when it gets to the ANT1 mark. Or if you want to check the revs borrow an automotive multimeter with an RPM lead that clamps onto your HT lead.

The ridiculously cheap digital hour meter/tachometers from China available on Ebay (£6) do actually work. I have one on the Forgotten Error. They 'lag' a bit but good enough for an ignition advance check. I've even got one on the 1957 Gilera 175. I put it on because I thought when I first got it that it didn't rev out as it should. That turned out to be stuck ATD bob weights. Much better now, but I've kept it on as my 'seat of the pants' , mechanical sympathy, tacho needs adjusting to something that produces peak power at 6000 rpm and max torque at 4500 after riding a wee vee

[fofs216]

Cheers Steve and 72degreees,
I'll take a look at those chinese revcounters, cheers! I'm assuming that a radically increased valve clearance will tell me i've bent a valve and or a pushrod!!!
Cheers again,
Jamie

[Ming]

I had a belt snap on a Kanguro some years back - an odd sensation, sudden silence followed by a coast to standstill - which fortunately only shortened the rods (they have a telescoping section at the top). It would have been possible to reuse them, but without the safety feature.

[fofs216]

Hi Ming,

That's exactly what happenned! Ghotly silence, followed by a coast to stop, i was hoping that the lack of a bang, crunch etc meant i got away with minimal damage but i suspect that's just me being hopeful!!!

The funny thig is I've used the bike for a fair bit of off roading last year including the Malle Mile etc and it let go coasting into town for a beer before the rugby on Sunday

Cheers,
Jamie

[Ming]

Yes, I was tootling back from a Bike Meet near La Chatre and was mooching along the Indre. I suspect that helped limit the damage to the pushrods.

[fofs216]

Camblet changed and thankfully all good!

Pushrods were straight and the correct length, rockers all good. The washer that keeps the belt on the crankshaft pulley was actually placed on after the 'small' spring which is odd so corrected that.

Cheap electronic tacho and strobe allowed me to check the timing too.

Very pleased

[Steve Brown]

Camblet changed and thankfully all good!

Pushrods were straight and the correct length, rockers all good. The washer that keeps the belt on the crankshaft pulley was actually placed on after the 'small' spring which is odd so corrected that.

Cheap electronic tacho and strobe allowed me to check the timing too.

Very pleased

That must all be a relief! I wonder if the wrong assembly of the cambelt guide washers caused the belt to fail?

[fofs216]

Hi Steve,

Possibly, overall the belt looked ok but it may have. so relieved that's she's running ok again

Cheers,
Jamie