Jim Scmidt & Keihans....

I have booked the Commando in for the 'Festival of 1000 bikes' here in the UK at Mallory Park race circuit in July. As such the Mikuni VM34 is coming off and last Sunday I ordered some 32mm flatslides off Jim as I am currentky in San Francisco for a conference. They arrived Tuesday at the hotel. Thanks Jim, can't wait to get them on the bike, great service. Mikuni going on ebay.

I am sure you will be pleased with your purchase. It is a very easy switch over.

FastFred said:

I have booked the Commando in for the 'Festival of 1000 bikes' here in the UK at Mallory Park race circuit in July.

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So have I will be interesting to see if your Keihins are a match for dual 32 Amals. :wink:

FastFred said:

I have booked the Commando in for the 'Festival of 1000 bikes' here in the UK at Mallory Park race circuit in July. As such the Mikuni VM34 is coming off and last Sunday I ordered some 32mm flatslides off Jim as I am currentky in San Francisco for a conference. They arrived Tuesday at the hotel. Thanks Jim, can't wait to get them on the bike, great service. Mikuni going on ebay.

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Fred,

Enjoy Mallory....but with new carbs you might want to spend a little more time at Mallory, make sure its all working as you want before the big weekend :wink:

On the weekend before, 30th June and 1st July it is the Classic Racing Motorcycle Club race weekend at Mallory.... www.crmc.co.uk

And there is also a classic bike track day the Friday before that, the 29th June...... http://www.classicbiketrackdays.com/mallory.shtml £129

The track day organisers are regulars in the CRMC paddock, should be a good mix of bikes, with probably more track time and space than you will get at the Festival, though I am sure that has a special atmosphere with all the ex world championship race bikes and riders.....I hope to enter the race meeting with a Rickman Norton, maybe a Suzuki....not sure yet exactly what, or about the practice day....tight budget this year...

I have had mine for about 18 months now and I think they are wonderful.

Mine are stamped PWK as I believe all these carb bodies Jim offers are.

Mine start second kick from cold, idle very well, and flow beautifully all through the rev range.

Has anyone looked at the fuel consumption on these marvellous devices? Better or worse than twin amals?

crusadersports said:

Has anyone looked at the fuel consumption on these marvellous devices? Better or worse than twin amals?

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Below is from a previous post:

Re: JS Motorsports Carbs
by Brooking 850 » Mon Jan 30, 2012 11:06 am

I have just completed a 817 mile (1315 km) trip to and from the NOC NZ rally and kept an accurate record of the fuel useage with my JS carbs.
Riding consisted of fast twisty country road runs, winding and hilly highways, wet and dry conditions and fast pace on country back roads.
All in all the conditions you would normally encounter here in New Zealand.
i tend to run at 3800 to 4200 rpm and rarely rev it over 5000 rpm.
i had the oppurtunity to run against at least three bikes with single Mikunis and in once case a bike with twin Mikunis. The good thing is that all bikes I ran with and compared fuel consumption are all 850's, some more trick than mine, but overall very similar.The 3 guys with the single Mikunis all have the same riding style as we all road together back in the day !!!
After one hard twisty run, the twin carb Mikunis used more than mine, the single Mikunis overall were always within points of a liter difference so for the sake of the exercise I have called their useage the same.
Total distance traveled = 817 miles or 1315 km
Total fuel used = 18 Imperial gallons or 81.13 litres ( 4.5l to Imperial gallon) In the US gallon this equals 3.8 litres
Average Fuel Consumption = 45.4 mpg or 16.20 kms per litre
I did get as much as 53 mpg on general highway use at 3600 to 3800 rpm generl highway running on three different trips over the same stretch of highway about 3 hours running return trips.
Hope this helpful to you all
Regards Mike

Thanks Jim, will be up for a second set for the next project on Bike#2
Regards Mike

Cheers guys. Might look at that classic bike track day.

Snakehips your dead meat, forget it, condition your mind to seeing the back of my bike disappear...Should be fun, are you camping?

FastFred said:

Cheers guys. Might look at that classic bike track day.

Snakehips your dead meat, forget it, condition your mind to seeing the back of my bike disappear...Should be fun, are you camping?

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Hi Fred, lets hope the weather is good, this could be fun especially if we get the same track sessions. Yes I will be camping, have some mates going one with a Mk3 one with a MK2a and of course my 750. Will have to touch base again when the programs are sent out.
Best

Mileage calculations----in USA would be approx. 38 MPG. 81.13L /3.7854 = 21.4323 gallons 817/21.4323 = 38.1200 mpg

Anyone else have any gas milage figures to compare?

I get low to mid 50s with a pair of 35mm Keihin FCRs. Have gotten as much as low 60s under "ideal" conditions (long cruise at about 50 mph on a two/three lane highway with very few stops). Bike is a 73 850.

I never used the stock Amals so I can't compare to those.

I think the OP is referring to his new PWK 32mm flatslides, much different than 35mm FCR's?

1up3down said:

I think the OP is referring to his new PWK 32mm flatslides, much different than 35mm FCR's?

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Thanks 1up, yes, I did mean the PWK 32mm flatsides.

45-50 mpg sounds about right twin Amals in reasonable nick- so these new PWK flatsides sound about the same in terms of fuel consumption. Interesting! In every other way the PWKs sound superior but as petrol is so expensive, abit more mpg data would be welcome and valuable

MPG is sooo relative with these bikes with any carbs. One mans 40 is another mans 60mpg. When i cruise the country with the misses on her little F650, I can get around 60mpg. When I am on my own on the same trek it goes right out the window.

If you're braking alot, then sure as shit you're pulling on that throttle cable to match.
Although it by may or may not be negligable, good carbs with efficient metering is going to help with MPG along with all aspect of tuning.

But come on guy and gals, let's get real here. I don't wrench and fiddle to be fluffy and neither do you. Feel it, hear it, see it. Gotta love it.