Y Pieces

[Rob Farmer]

What sort of fuel consumption were / are you getting Rob with varied riding? I'm guessing mine is around 45mpg.

Plus while I'm asking is there much to be gained from dropping the needle when up in the higher Alps passes. Not thinking about changing half way up the Grossglockner ....

My set up, stainless headers without cross piece, y-piece but not a Keihan, Laser exhaust and 2nd needle from the top.

The fuel consumption was in the mid 30's The last time I filled up I'd used £15 worth of fuel in 137 miles but that also covered the dyno runs and a few Yeehaa miles after

So your on the 2nd notch instead of the standard 3rd as well?

I wouldn't have a clue with jetting for high altitude

 

[John Armstrong]

So your on the 2nd notch instead of the standard 3rd as well?

I wouldn't have a clue with jetting for high altitude

Fairly sure.

I think the problem is that the carb doesn't measure mass flow but airspeed and at altitude they tend to go rich due to the lack of air

 

[John Armstrong]

Nooooo... to rich for me. Its the HE disk and caliper from Motoren Israel - link - Israel make the caliper adaptor.

Ta looks nice set up.

 

[Redboots]

at altitude they tend to go rich due to the lack of air

Yup. Unless you live at altitude or are doing serious stuff up there, its not worth the effort...IMPO...

At 4700 mtrs there aint a lot of power left and it pinks like a bastard but at 2500 to 3000 its OK. Nothing higher than that in the Alps - tarmac that is

John

 

[John Armstrong]

I'll not mess before going to the Dolomites then

 

[SJRoome]

Hi Rob

Hi Rob

I am a bit of a fanatic about carbs. I have just done my annual carb strip down, clean and re-assembly, so everything in the carb is very clean. The setup on my R100GS is absolutely standard i.e. 150 main jet with the needle in 3rd position.

Steve

 

[Redboots]

I'll not mess before going to the Dolomites then

Boring weekend so stuck this up to prove that altitude is no probs

John

 

[John Armstrong]

4280m

 

[Redboots]

4280m

That's the LOW stuff John!

http://www.youtube.com/watch?v=RpM1FFv8pR0

John

 

[Rob Farmer]

Fitted the new collector box today. What an improvement. Bikes now very smooth and goes like Billyo. It's cut the exhaust volume by around half I'd guess. Big improvement in mid and top end. I may spend another £30 on a dyno run and see what's happening now.

Well worth the £190

 

[Redboots]

Fitted the new collector box today. What an improvement.

I hope mines not the same. Yet to fire it up with the Keihan Y pipe on

John

 

[AliBaba]

Fitted the new collector box today. What an improvement. Bikes now very smooth and goes like Billyo. It's cut the exhaust volume by around half I'd guess. Big improvement in mid and top end. I may spend another £30 on a dyno run and see what's happening now.

Well worth the £190

Yes it’s nice isn’t it?
Please take another dyno and post the result here!

 

[bustupbiker]

Fitted the new collector box today. What an improvement. Bikes now very smooth and goes like Billyo. It's cut the exhaust volume by around half I'd guess. Big improvement in mid and top end. I may spend another £30 on a dyno run and see what's happening now.

Well worth the £190

£190 for a collector box Rob! was going to get one my self to replace the Y pipe as it hits the new Migstand and buzzzzzzzzzzzesssssssss like mad,
but at that price i will try and weld the old un up
Lyn.

 

[SJRoome]

Rob

When are we going to see the dyno results? The suspense is killing me.

Steve

 

[Rob Farmer]

When I can make it to the dyno Steve. Stafford show this weekend so maybe the week after.

 

[Graham W]

In the interests of experimentation I dropped the needles on mine ('92 R100GS with 'Y' piece) by a notch after reading this thread first time around . . .

. . and it goes so much better, with a usefully decent increase in urge above about 3K.

The best bit is perhaps that the fuel consumption has gone from low 40's up to an average of around 48 mpg and a best on the last tank of 50.8mpg

After 600 miles or so now including a hard thrash up through mid Wales this morning the plugs look fine. Very happy.

Thanks for posting that, Rob.

 

[Rob Farmer]

See! all you folks were wrong to snigger.

Glad it worked for you Graham

 

[SJRoome]

Rob

Still not seen those dyno results! Were they so bad you dont want to share them with us?

Steve

 

[Rob Farmer]

No Steve Just didn't want to spend £30. Of course if you would like to chip in I'd be only to pleased to take it along

I haven't had a chance yet. The best time to take it there is in the week and that means booking holidays.

 

[Redboots]

I have now run mine with the Keihan Y pipe and I would not say I notice anything negative, power wise.
Carbs stripped and rebuilt with new jets/needles. I dropped the needles one notch. Airbox rubbish is all stripped out, vacuum pipes done away with, air inlets on the exhaust side of the head bunged up and the breather routed to atmosphere. K&N filter fitted.

It does "bark" a bit though... almost sounds like a baffle is loose...

So far, I like it