Carburettor Autolube Connection - TY175

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Jimbo
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Carburettor Autolube Connection - TY175

Postby Jimbo » Mon Oct 31, 2011 10:20 am

GDay All
Im getting my head around the mods that have been done to my newly acquired TY-175
The autolube pump has been disconnected, and from my reading, I gather the unused oil-line on the carb must be blocked off, or it will suck air, and run lean.

I should point out - the bike starts first kick, and runs quite well (a tad smoky, perhaps)

The previous owner insists the premix ratio MUST be 30:1 which sounds a bit rich; I was thinking it should be more like 50:1 (comments, anyone?)

The 30:1 requirement is what prompted me to confirm that the oil-line was correctly blocked. When I took the oil-pump cover off, two cupfuls of rusty brown water poured out! Eeek! The cable hole had been blocked with a bolt, so I assume water was getting in at the top of the cover, but being held from escaping.. The pump was in place, but wrapped in 5mm of brown sludge. Fixed now.

[Q] Ive attached some photos - Can someone point out where the oil-line used to go on on the carb? (A bit of a naive question, I know)
[Q] You will see I have 3 breather/drain lines - is this normal?

Thanks Guys

TyCarbL-sm.JPG
TY-175 Carburettor (L)
TyCarbL-sm.JPG (24.04 KiB) Viewed 3712 times
TyCarbR-sm.JPG
TY-175 Carburettor (R)
TyCarbR-sm.JPG (22.67 KiB) Viewed 3712 times



David Lahey
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Re: Carburettor Autolube Connection - TY175

Postby David Lahey » Mon Oct 31, 2011 10:44 am

In the left side photo the oil port is the one closest to the cylinder. Hole points horizontal right. Can't tell what yours is plugged with from that photo but whatever it is it appears to be sticking out 10-12mm from the carby body

The vent and overflow hoses are all correctly fitted. The one that comes out the bottom is the float bowl overflow line. It is a standpipe. Other hoses are float bowl breathers

It shouldn't smoke at 30:1 with normal modern 2 stroke oil. It might have a leaking crankshaft seal on the clutch side. Tests for this are:
To see if it consumes gearbox oil with use
If the exhaust fumes smell wrong

The oil pump can be removed to save weight. It will need a plate fitted to replace it and you have to remove the clutch cover to remove the pump.


relax, nothing is under control

FM350
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Re: Carburettor Autolube Connection - TY175

Postby FM350 » Mon Oct 31, 2011 6:28 pm

The only result of using 30:1 mix will be an exhaust which is completely clogged, and will need to be cut open to clean out properly. Trials motors simply dont need as much oil as this person suggests, and using a proper fully synthetic 2T oil intended for pre-mix competition machines, you will find it will run an awful lot better on 70:1.

However most "fully synthetic" 2T oils are nothing of the sort, as they are intended for use in autolube road going machines, and are inclusive of low smoke additives, which are very thick and have to be thinned by up to 20% kerosene to make the oils thin enough for use in autolube systems, which are expected to work at very low temperatures!

Here in the UK Castrol XR77 is a proper fully synthetic oil designed for pre-mix machines, and its higher viscosity has the added advantage of providing much better corrosion protection on machines which may be used infrequently, over the much thinner scooter type "fully synthetic" oils which in reality are nothing of the sort!



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Re: Carburettor Autolube Connection - TY175

Postby Jon V8 » Mon Oct 31, 2011 6:51 pm

FM350 wrote:The only result of using 30:1 mix will be an exhaust which is completely clogged, and will need to be cut open to clean out properly. Trials motors simply dont need as much oil as this person suggests, and using a proper fully synthetic 2T oil intended for pre-mix competition machines, you will find it will run an awful lot better on 70:1.

However most "fully synthetic" 2T oils are nothing of the sort, as they are intended for use in autolube road going machines, and are inclusive of low smoke additives, which are very thick and have to be thinned by up to 20% kerosene to make the oils thin enough for use in autolube systems, which are expected to work at very low temperatures!

Here in the UK Castrol XR77 is a proper fully synthetic oil designed for pre-mix machines, and its higher viscosity has the added advantage of providing much better corrosion protection on machines which may be used infrequently, over the much thinner scooter type "fully synthetic" oils which in reality are nothing of the sort!

The row about oil mix will go on forever in all areas of two stroke use,and is not worth entering. But if a product is specced as fully synthetic,and it isnt - there is a trade descriptions issue.I dont think oil companies are daft enough to market oil that isnt what they say it is.Even supermarket oils have some form of SAE/ACEA markings on them.



FM350
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Re: Carburettor Autolube Connection - TY175

Postby FM350 » Mon Oct 31, 2011 7:18 pm

Its pretty easy to tell if you have a proper fully synthetic pre-mix oil, rather than something intended for scooters. Scooter oils are invariably very thin due to use of kerosene to dilute the low smoke additive and will also be JASO rated. Competition type fully synthetic oils are generally around SAE30, and due to lack of low smoke additives wont have a JASO rating.

I wouldnt think that wear would be an issue for anyone using a scooter oil, but the very low viscosity means that amount of residual oil inside the motor after running isnt likely to be as much as a proper competition pre-mix oil, and may lead to problems with corrosion on bikes that are used infrequently. As proper pre-mix type oils dont cost much more than the scooter types, why bother to use something that might not be as good?



TriCub
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Re: Carburettor Autolube Connection - TY175

Postby TriCub » Tue Nov 01, 2011 10:28 am

JImbo.
I don't like getting into the oil fuel ratio discusion but when someone who lives in a cold climate tell you to run your old aircooled machine at 70:1 here in Australia I feel I need to set you straight. I'll just start by telling you that I have a small engineering buisness and have been doing rebores and crank rebuilds for over 25 years. If you run your TY at 70:1 in our hot summer conditions you will have a very short life engine. With 30:1 there will be a bit of smoke when you give it a hard time and there will be a bit of oil build up in the muffler but the engine will not oil up plugs or run bad and it will last way longer.



FM350
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Re: Carburettor Autolube Connection - TY175

Postby FM350 » Tue Nov 01, 2011 1:41 pm

Interesting.............how much higher is the piston crown temperature on an air-cooled bike being used in Aus, than one being used in the UK say?




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