Extra pipework

[tridentperu]

Hi,

I'm gradually working my way through my rather scruffy Monster 600 - carb version 1999 - sorting out dodgy electrics etc and have found some pipework that isn't in the parts book.

From the front right of the motor a braided type hose goes up to one of the carb float bowls, branches off to a tap (that shuts off the flow to the next carb) the tap is clearly meant to be there, as it is mounted to the frame, then onto the next carb. The pipe then branches off and returns to the front right again - looks like oil cooler take off points...

Any ideas please?

I'll post some pics if need be

Thanks

Jim

[Flip]

Sounds like carb float bowl heaters to me.

The oil cooler equipped models have a similar set up with it taking a feed from the oil cooler itself. The tap simply opens the flow to the carbs (for Winter riding) or closes it (for summer riding).

[Mr Gazza]

That will be a carb warming kit.
It circulates engine oil round the float bowls when the tap is turned on. (The lever will line up with the pipe when turned on and sit at right angles when shut.)

The idea is to stop the carbs icing up when the humidity is high and it's a bit chilly...Sort of autumnal type weather, not necessarily freezing conditions.

I've never seen a carb warmer plumbed without an oil cooler, but clearly this is a standard fitment
With an oil cooler the tap is a bypass type, so the cooler is always in circulation regardless of tap position . The tap simply brings the carbs into the circuit as well when operated.

[tridentperu]

Hi,

Thanks, I wondered if it was something like that but wasn't sure as I wouldn't have guessed it would be necessary with the carbs above the hot motor!

No oil cooler fitted and no sign there ever was one.

Cheers,

Jim

[Mr Gazza]

Thinking about this a bit more your tap has to be a bypass type, because that loop of pipe needs to circulate oil all the time. it can send oil round the carbs or short circuit it back to the engine, but must not be shut off as it is inline between the oil pump and the big end shells... Correct me if I'm wrong anyone?

[Luddite]

Originally Posted by Mr Gazza

Thinking about this a bit more your tap has to be a bypass type, because that loop of pipe needs to circulate oil all the time. it can send oil round the carbs or short circuit it back to the engine, but must not be shut off as it is inline between the oil pump and the big end shells... Correct me if I'm wrong anyone?

For what it's worth, here's the Stein-Dinse diagram for the 600 (with no oil cooler).



It looks from this as though the tap is just on/off rather than a bypass. Oil flowing out of the engine along hose 4 to the tap 8, then to the first float bowl via hose 10, to the second bowl via link-hose 9, and then finally back to the engine via hose 3.

The later model, without the heater, just appears to have the two oil ports blanked off with bolts 42.



So when the tap is closed on the earlier model, it's effectively replicating the blanking bolts on the later model.

Or not?

[Flip]

Now I'm home from work I've just had a look through my 1997 accessories catalogue and it was available as a kit for the non oil cooler models. Part number 69920571A.

Popped that into ebay and this came up as being sold by HGB:

https://www.ebay.com/itm/NEW-GENUINE...p2047675.l2557

Originally Posted by tridentperu

Hi,

Thanks, I wondered if it was something like that but wasn't sure as I wouldn't have guessed it would be necessary with the carbs above the hot motor!

No oil cooler fitted and no sign there ever was one.

Cheers,

Jim

It's not when the fuel is a liquid that is the problem it's when it's turned into a vapour in the emulsion tubes, which under certain conditions can freeze momentarily as it mixes with cold air causing the motor to misbehave a little.

Some bikes seem more prone to it than others and some people say fuel additives through the Autumn and Winter months can help.

[Darren69]

Originally Posted by Flip

Now I'm home from work I've just had a look through my 1997 accessories catalogue and it was available as a kit for the non oil cooler models. Part number 69920571A.

Popped that into ebay and this came up as being sold by HGB:

https://www.ebay.com/itm/NEW-GENUINE...p2047675.l2557




It's not when the fuel is a liquid that is the problem it's when it's turned into a vapour in the emulsion tubes, which under certain conditions can freeze momentarily as it mixes with cold air causing the motor to misbehave a little.

Some bikes seem more prone to it than others and some people say fuel additives through the Autumn and Winter months can help.

I had an oil heater on my 900SS, complete waste of time; like you say its not when the fuel is in the float bowls it needs to be heated. Additives like pro FST do help a bit and I fitted a plate in front of the carbs to deflect the cold air which also helps, partially covering the oil cooler raises the engine ambient temp as well but none were 100% cure.

I gave up in the end sold the bike and bought a 748.

[Nickj]

Had the same on a 600ss didn't seem to make much difference to how well or badly it ran.

[Nickj]

I also had a 2001ish 750 that had slightly more techy electric bowl heaters, again they didn't seem to actually do anything useful.

In both I found that decent fuel that wasn't full of water (that is ethanol free) worked most of the time but FST was about the only reliable answer.

[tridentperu]

Thanks all for your inputs - it is exactly that kit that was for sale on Ebay. An optional heater for the carbs.


Mystery solved - now onto the next problem when/if it surfaces...which it will!

J