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How often should you top up the oil in the dashpots? My car has twin strombergs and I seem to have to top them up evrey time I use it. Today I checked them before I left and they were about halfway down the tube, when I got home after a round trip of about 50 miles (and a day sat in a field in the rain [:(]) they were empty. As far as I know the oil should be about half an inch down from the threads? Is this normal oil use or are they leaking oil somewhere? I seem to remember the SU's on my TR7 also used lots of oil.

Andy
1981 UK SPEC TR8
[img][IMG]http://i473.photobucket.com/albums/rr92/REPLIC8-2008/175-1.jpg[/img][/img] [img][IMG]http://i473.photobucket.com/albums/rr92/REPLIC8-2008/pics005.jpg[/img][/img]

I find SU's are the same which is one reason I use 20/50 left in the can instead of dashpot oil (plus 20/50 is thicker and theoretically gives a bit more acceleration, not that I have ever noticed it, probably because it does not stay in long enough).

Alan
Saab 9000 Stg 1
Saab 9000 2.3 FPT Auto
Saab 2.3 LPT Auto
'81 TR7 DHC

<font color="teal"><b>As a boy (17 /18)

we used to put brake fluid in and was supposed to be better acceleration

don't know if we were just kidding ourselves

has anybody heard of this?</b></font id="teal">

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<font size="4"><font color="green"><i>If it's not broke don't fix it.</i></font id="green"></font id="size4">

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Interesting opposite! I was always told that a thicker oil made the piston fall slower, keeping the mixture richer. Kids theories I suppose.

Alan
Saab 9000 Stg 1
Saab 9000 2.3 FPT Auto
Saab 2.3 LPT Auto
'81 TR7 DHC

<font color="teal"><b>I see your point, it may have been faster throttle response ( cant remember now)

would be interesting to find out

as you say "Kids theories I suppose"</b></font id="teal">

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<font size="4"><font color="green"><i>If it's not broke don't fix it.</i></font id="green"></font id="size4">

http://www.smallbiztranscripts.co.uk

The rubber O-ring on the brass screw has deteriorated allowing the oil to drain into the intake tract. The good news is the O-ring is cheap.

The bad news is replacing the O-ring will necessitate the resetting of the mixtures and a general tuning re-balance of the carburetor set.

Mildred Hargis

I'm assuming this is the o ring that comes on the needle adjuster. These were only replaced last year. Maybe I'll try thicker oil (20/50) and carry some in the car so I can top up at shows etc before the trip home. Surely these were originally supposed to stay topped up between services, or was it a regular maintenance chore?

Andy
1981 UK SPEC TR8
[img][IMG]http://i473.photobucket.com/albums/rr92/REPLIC8-2008/175-1.jpg[/img][/img] [img][IMG]http://i473.photobucket.com/albums/rr92/REPLIC8-2008/pics005.jpg[/img][/img]

I top up my SUs oil about once every 6000Km, using 20W50 engine oil, & they are still offering full resistance at that time. You should not have to do it more often.

We used to run a machine oil, about SAE 10 in SUs back in the 60s when I was racing using them. However in those days of copper floats, with an adjustable to act on the needle, we had better control of the float level in our carbs. For normal road work we ran it at 1/8" below the top of the main jet, bringing it up to 1/16" for competition.

This higher level would have made them a bit more responsive than ours today.

Hasbeen

Hi Andy,

It is a service item BUT not a weekly one !!

This is the o ring -





Cheers John


LIVE LIFE A QUARTER OF A MILE AT A TIME!

1976 Speke FHC Beauty

1979 3.5 FHC(STATUS PENDING!!)

1982 2.0 DHC NOW A 4.6,ON THE ROAD NOW KICKING AR5E !!!!

O-rings can be made from different materials, some that don't stand up to gas/oil environments. Just because it's in a kit doesn't mean it's the right one. A knowledgeable O ring place should get you the right one. See link below which materials are suitable for what environments.

http://www.marcorubber.com/material_chart.htm



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