Performance Carb Suggestions

Cafe_Shop · Posted: March 5, 2007, 11:14 pm Post subject: Performance Carb Suggestions

I'm going to buy a new set of Mikuni round slides soon. Does anybody have any suggestions as to what size or supplier?

RainLand · Posted: March 6, 2007, 9:37 am Post subject: Re: Performance Carb Suggestions

I got a set of 36mm roundslides off EBay - I'm mating them up to a 750
kit and a mild port job.

Cafe_Shop · Posted: March 6, 2007, 11:55 am Post subject: Re: Performance Carb Suggestions

Were they from Sporting for Less? I've not heard anything good about them. Maybe somebody can testify otherwise? I do like their prices.

5twins · Full Member Joined: Aug 05, 2006 Posts: 1616

deleted

Cafe_Shop · Posted: March 6, 2007, 3:16 pm Post subject: Re: Performance Carb Suggestions

Thanks. That's the information I'm looking for.

danno · Full Member Joined: Mar 04, 2006 Posts: 212

What will the Mik 34's do to fuel mileage on a stock motor? I am thinking about swapping the stock cv carbs. Thanx.

tracker79 · Posted: March 6, 2007, 8:19 pm Post subject: Re: Performance Carb Suggestions

sfl...something for less as i call it. Everything 5twins stated is what i got, nothing but headaches. I guess i got what i paid for.

RainLand · Posted: March 6, 2007, 9:49 pm Post subject: Re: Performance Carb Suggestions

The 36mm seems to be the same inner diameter of the port, after the
shoulder is removed. Do you mean they match before the mod?

ttmaniac · Full Member Joined: Dec 22, 2006 Posts: 468

Go 36mm all the way. You will not be dissappointed. This way when you start modding your bike you don't have to buy bigger carbs. Some people say that the bigger carb is lacking with a stock motor. Never had any problems with mine. Although I'm not running a putt putt machine geared for bonneville either. PRO-FLO carries roundslide and flatside carbs at competitive prices.

Jake68 · 650Rider Supporter Joined: Mar 23, 2007 Posts: 841

Has anyone actually conducted flow tests between the VM carbs and the standard carb types? I cant see that there would actually be that much in it as the butterfly is so close to the valve.

It also seems to me that there may be an easy round slide conversion available from the standard carb bodies?

Or am I mad.

ttmaniac · Full Member Joined: Dec 22, 2006 Posts: 468

you could turn stock carbs into roundslides. A mill would be handy for that. Too much messing around though. I don't think 300 bucks is bad for carbs that last forever.

xs1961 · Posted: May 4, 2007, 3:38 pm Post subject: Re: Performance Carb Suggestions

I find that 34mm Mikunis roundslides (from Sportingforless for half the price they cost here in the UK !) offer the best allround performance & economy,I run them on my 840 & 750 they give instant throttle response & 50+ MPG!
I found the 36mm completely unneccessary,had to jet them down to the same as the 34mm's anyhow.
36's look too big,they ARE too big (unless youre running a drag spec XS).
Large carbs only have the advantage in full throttle applications-when did anyone ever run an XS650/750/840 at full throttle?!

jayel · Posted: May 4, 2007, 9:54 pm Post subject: Re: Performance Carb Suggestions

when did anyone ever run an XS650/750/840 at full throttle?

ever heard of Kenny Roberts?

xs1961 · Posted: May 5, 2007, 6:41 am Post subject: Re: Performance Carb Suggestions

Ok Ok

...Anyone able to ride an XS full throttle ON THE ROAD(or highway over there)? I cant Embarassed

The XS is a great motor but it really starts to protest over 6500 rpm (anyone know of a 4valve conversion? Wink

)
Ive run my 34mm Mikuni equipped 840 along the 'dragstrip' at Ramsey sprint on Isle of Man several times & its never felt fuel-starved & no,even then I dont think I ever had the twist-grip wound all the way back!

Buzz · Full Member Joined: Jun 27, 2005 Posts: 37

I made the mistake of buying my carbs from SFL. Mistake, yes Screwed, No.
I bought my pilots and mains from Mike's $8 and jets & jet needles from
www.motorcyclecarbs.com for $18.
$26 later it should run great.

xs1961 · Posted: May 5, 2007, 11:26 am Post subject: Re: Performance Carb Suggestions

They were so cheap from SFL ($200 a pair when I bought them)compared to the rip-off prices over here in the UK £280+ ($380 ?) approx., that I had no problem spending £20 or so on re-jetting ,only needed 2 needle jets + mains.
Well happy ! Smile

Wish they'd answer the the emails though..... Evil or Very Mad

kingwj · Posted: May 5, 2007, 1:10 pm Post subject: Re: Performance Carb Suggestions

If you give me £280 I'll give you $380 anytime. I believe GWB has let the dollar slide to about £1=$2. Now is the time for you to buy stuff here in the US.

We even have the Queen visiting for a few days.

xs1961 · Posted: May 5, 2007, 3:33 pm Post subject: Re: Performance Carb Suggestions

Ooops...got my currency conversion in reverse Embarassed

...I meant £280 = to approx. $500 Confused

As you say ,bargain time for us Brits,my garage is overflowing with XS parts from Ebay US ! Smile

xsjohn · Last edited by xsjohn on January 2, 2008, 9:02 am; edited 1 time in total

Didn't make any of the above choices and kept my stock 34's....Just mad some kits for them....all is good now.......

John Underwood

ttmaniac · Full Member Joined: Dec 22, 2006 Posts: 468

36mm rules. Half of you guys talk about freeway riding. When you are in those upper rpm's and the goofy broad in the school bus sized suv forces you to make a full on throttle roll, then tell me about your 34mm's while they scrape you off the pavement. More fuel=more power.

I'm sick of this stupid argument. King Kenny never ran 34 mm. The smaller carbs ain't gonna give any significant major improvement down low over a 36. Yeah, yeah....airspeed is faster at lower rpm...so what. Why don't you run one carb then if you want off the line torque? I'll see you 34mm lovers when you nose over hard at 6000 and you suck rich exhaust from my 36's as I wail by you!

tracker79 · Posted: May 8, 2007, 10:23 pm Post subject: Re: Performance Carb Suggestions

Nose over at 6000? Mine pulls clean to 7500 with the stock carbs, might be alittle faster with the bigger carbs, its just a play bike. If a wanna haul ass it wont be on one of these dinosaurs.

ttmaniac · Full Member Joined: Dec 22, 2006 Posts: 468

No, if ya wanna haul ass you get 36mm's. End of my part of discussion.

ttmaniac · Full Member Joined: Dec 22, 2006 Posts: 468

And compression...sorry.

xsjohn · Posted: May 8, 2007, 11:05 pm Post subject: Re: Performance Carb Suggestions

No 34 lover I just ain't crazy enought to pay hundreds for 2mm when I already have carbs that work fine. If you are reving these things to 7000 then why don't you just buy a bigger motorcycle instead of destroying them just because you can.....

John Underwood

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Yamaha xs650