Triumphrat

tribsa1954

Interesting about the rockerbox breather, I have fitted a Bunn system to mine which breathes in from behind the crankcase and exits using the standard primary breather (bottom->bottom breather system) and I have found this has helped keep the top end leak free as I suppose it removes pressure from the top end,(I did have a slight prt weep but that has since stopped after fitting the breather kit), so that would be something I would have to think about if I was to consider sealing the primary off.

Old Cafe Racer

I originally fitted a Bunn breather kit, breathing in at the timing plug and out at the rockerbox both via the supplied one way valves.
Two things happened that I didn't like, first the valves were really noisy and had to be covered in silencing foam and second the "specially made" oil proof hose was very poor and started to crack at every bend after a few days.
So I simply got rid, refitted the timing plug and just fitted a hose to the exhaust rockerbox fitting same as I used to do back in the day.
Zero oil leaks anywhere for the last 700 miles.

Life is good.

tribsa1954

Lol - yes the valves do make it sound like the old boys on a ventilator!

All the best

furious furball

How in the world do you have next to no oil in your rockerbox outlet hose? I have the same set-up but with an inlet system in the TDC hole. My outlet hose goes up and then along the bottom of the fuel tank, down the OIF tank and out the bottom of the bike behind the gearbox. Each ride I have immediate drippage of oil from the blow-by gases which slowly puddles up to approx the size of a 5-inch circle before it finishes dripping about a day later.

I'm working on my solution this weekend which is installing an aluminum catch can from Pegasus Racing ($20) behind my side cover so its concealed. Both the inlet and outlet hoses have Krankvents in the correct direction of air flow. I figure with the catch can I will at least be able to control the oil out of the hose instead of leaving the usual Triumph signature wherever I park.

I've got another post on the forum about this but my last trick to perform is figuring out how to stop the gearbox oil from coming out of the foot change spindle hole (left side gear change). I currently added an o-ring on the foot change spindle where it meets up with the hole - that worked for most of my last ride but not the entire ride - at least minimalized the oil leak - however did cause the gear changing to be a bit tougher then with no o-ring.

Re: the original post - I too have a BNR belt drive and converted to dry clutch (as the above indicates). Love it so far, minus the oil drips as noted above I'm still working out. I highly recommend the BNR set up, sealed bearing, 7lbs of loss weight (brother-in-law says in rotational weight it likes removing 49 static lbs) and looks hella kewl. Uber easy to fit, direct replacement.

Old Cafe Racer

[quote=furious furball;2449650 How in the world do you have next to no oil in your rockerbox outlet hose? I have the same set-up but with an inlet system in the TDC hole. My outlet hose goes up and then along the bottom of the fuel tank, down the OIF tank and out the bottom of the bike behind the gearbox. Each ride I have immediate drippage of oil from the blow-by gases which slowly puddles up to approx the size of a 5-inch circle before it finishes dripping about a day later.[/quote]

Well that's all I have, I get about 2 drops in the catch bottle every 50 miles or so, it varies with how hard I rev the engine.
If I keep it below 4500rpm there is virtually nothing in it.
Catch tank is a carbon fiber wrapped plastic Castrol coolant bottle which sits comfortably between the front engine plates.

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Mr.Pete

I think your brother-in-law should revise his mathematics.I estimate that primary chain surface speed is approx 0.64 times rear tyre circumference speed in top gear.
In 1st gear,primary chain speed is 1.6544 times tyre speed.

Even if all that mass was at chain pitch circle speed,it is effectively 3.737 x 7 lbs inertia =26 lbs of non-rotating mass,when the bike is in 1st gear.
In top gear,it's equal to 9.842 lbs of non-rotating mass.

Steve69

9 lbs of non-rotating mass!

stop eating burgers and you will lighten the bike + control system ( you) by much more than that.

Mr.Pete

The steel capped boots could be a few lbs,+ a few beers gives a few more.

Triton Thrasher

If we're talking about home made breathers, I think the sensible way to do it on a unit Triumph is through the crankcase front mounting lug. Requires the engine to be split, for drilling through from the crankshaft space and drilling and tapping for the outlet spigot and packing the lug with knitted nylon pot scrubber material. That gives you an oil catcher and scope for a vertical pipe run from the crankcase.

Also doesn't involve making Mr Bunn rich in exchange for some rather paltry pipes and valves.

Old Cafe Racer

I don't think Mr Bunn is getting rich on his breather kits but quality wise it had no place on my bike.

I also tried using the redundant tacho drive with the guts removed (electric tacho) as a breather point but it threw too much oil out being too close to the crankshaft/flywheel so the rockerbox cover it was.

Mine's also a 500 so breathing through the cast in engine mount isn't an option but that said I wouldn't even consider it for the same reason as the tacho drive (and the timing plug one I also tried) one didn't work for me.

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