What revs?

Just wondering what revs an 850 engine is safe to run at?
She seems very happy sitting at 5000 rpm which is 70mph in top gear but what can she safely run out to as we get there? The engine is over 33 years old and I am fearful of doing damage in my enthusiasm. I wrung her out to 7000 rpm in third gear yesterday chasing my friend on his Honda but I seem to have a little oil weep on the garage floor out of the engine breather, about a teaspoonful.
All the best,
David

Hi revs does that. Tho I read 5,000 as more like 80 mph (?) I make it about 622 rpm per 10 mph, so 120 mph @ 7,500 rpm checks out with all the performance data I’ve got. This is the yellow line on the rev counter. In my MG manual it incredibly says 850 Le Mans should do 144 mph, that’s well past the red line on my rev counter, getting on for 9,000, doubt it would go that fast On a dyno perhaps

On think it depends on the diff n wheel size

I revved mine far too hard some times and it loves it

Think my t5 is far too highly geared compared to my mates t3

I am rather unsure about the accuracy of both tachometer and speedo although they are both original fittings as far as I can see. The 5000 rpm mark and the 70 mph mark are both at the twelve o’clock positions on the dials. My bike is an 850-T3 Cali so I suppose may be geared differently than a LeMans.
So the oil spit is normal?
David.

Convert bevel box 4000=80 but an 850 has problems pulling in top

The T5 850 engine is an 81 engine happily goes up to 7000 thro the gears the 1000 engine at 36 yrs old did the same, yeah they will weep a bit at those revs but happily do it.

Speedos are very dodgy I got a sigma bike speedo easy to fit and calibrate and checked it against the sat nav…100% accurate BUT shows the errors in the Guzzi speedo up to 40 OK BUT 70= real 77 on one but 65 on a different speedo and once over 80 . well it just is not at all accurate. tacho should be more accurate.

Yes I took mine apart and adjusted the needle. And that was a new one!

you wont enjoy it till you get it reving my cali3 948cc hits 7000+ rpm regulaly, it dos weep a little oil from the breahter. but the motor loves it, ps its a 1988 and has done 87,000 mls.

Will the timing chain be OK for these sorts of revs?
I have not done anything to the bike in that area other than reattach wires to the alternator. Is there a tensioning system?
All the best,

Never heard of a timing chain break on a Guzzi.

There’s a rubber slipper block that just takes the slack out, it’s not an active tensioner in the true sense.

On my Cali 3 5000 revs is near as damn it 80 mph as confirmed by my sat nav.

The Guzzi seems happier revving that it does slogging around at low revs and at anything above 4000 revs the money I spent having the bottom end dynamically balanced pays off and it smooths out a treat.

When you haver the time etc fit the aftermarket upgrade auto tensioner in the timing chest. The chain is highly unlikely to break and the OEM tensioner only needs looking at every 12-15k miles…I have had only 3 timing chains in almost 300k miles…and 38 years one of those was replaced when the new auto tensioner went on as it was to bits rather than really had to be replaced

GMT that’s about standard the Convert bevel box IS high geared but I am stuck with it so it means low revs cruising BUT also means the 850 engine will not rev out in top, doing a deal to get the 1000 engine sorted and back in BUT that may not happen till this Winter.

Is it a big job to check the timing chain? Is the tensioner adjustable? The bike has done about 34000 miles before my ownership so I am bit apprehensive about reliability until I have checked everything.
All the best,

IF yopu can hear it rattling from the timing chest …leave it… If you hear a slight whine…leave it.

To get at the timing chest the altenator has to come off and the front engine bolt so you can undo the timing cover. IF you really don’t feel confidend doing it DON’T

To actually adjust the OEM one is relatively easy a 2 min job BUT to get at it takes a couple of hours. IF it has the aftermarket auto tensioner fitted it is self adjusting, they rarely give problems. If out of adjustment it rattles like crazy.

Tip: start the bike get it warm, use long handled screwdriver popped ontot he timing chest to Listen by popping the other end to the bone behind the ear.

Only 34,000 miles, just run in then for a Guzzi.If it was 234k I would start checking.

I’m about to have another go at this (but keep being interrupted!) I’ve got the strange situation that alloy gears are fitted BUT the timing is non-standard, so I had acquired a chain and sprockets to swap to and be absolutely sure of standard timing (can only go on one way). Slipper block bolts are 13mm AF, block is adjustable but you may find it’s reached the limit of its travel and chain is still slack, I think this means chain is ‘stretched’ and ought to be renewed. To pop the alternator rotor off needs special tool, the hardened steel rod; take out rotor centre allen bolt, insert rod and do up bolt again, rotor jumps off (literally, so make sure you catch it!). To do this lock engine in 5th gear with stout bar through rear spokes and resting on swingarm. Timing cover, allen screws. Camshaft nut, 26mm ring spanner. This is the pickle, crankshaft nut needs special 4-peg spanner / socket, and it also has a locking tabs washer. The other P.I.T.A. is all 3 sprockets and chain have to come off and back on as a complete unit, you can’t do them individually and then put the chain on for example. AND they’ve all got shaft keys that have to line up as well!

Sounds like a job to avoid then. I will listen to it carefully before going any further!
Thanks chaps.
David.

Actually it’s not that bad a job David and the chances are that a new chain and updated tensioner will make her run 'just that little bit " better