[Rick O'Shea]

Do you guys think the 30mm Flat-slide carb offered @ CMW is a noticeable improvement over the 28mm Micarb as pertaining to a cast-iron motor with classic exhaust & K&N?

[baird4444]

Do you guys think the 30mm Flat-slide carb offered @ CMW is a noticeable improvement over the 28mm Micarb as pertaining to a cast-iron motor with classic exhaust & K&N?

Absofrikenlutely. So long as the classic is a freer breathing silencer.; if not; you'll want something  that breathes better to take advantage the increased intake breathing of the K&N and larger cap. carb. I drilled thru my stock bazooka for the increase. Be prepared to give up some mpg's but it is worth  it. I laff every time I grab a handfull of throttle.
                     - Mike

[Rick O'Shea]

That much difference, huh? any thoughts on jetting; I'm between 2500' & 3500' during my commute to work. As I rebuild my Sixty-5 after the wreck I thought of the flat-slide, the mid-fifties English exhaust, K&N, better oil pumps, H-D clutch springs, just basically keep the innards stock; any thoughts?

[Slider]

Huge improvement.

[Slider]

...I thought of the flat-slide, the mid-fifties English exhaust, K&N...

I had the same set-up at first and it was great. I later replaced the K&N with the Ace coffee can and it was even better. I recommend spending a few extra dollars for the coffee can. That mod by itself made a noticeable difference over the K&N.

[baird4444]

My set up is a 25 slo jet and 138 main...  I'm at about 700'.
From the notes I've taken on everybody; we've all got different
set ups unlike the mikuni where you could guess a 27.5 pilot and
130 main would get ya. 
    I tried to get a file of comparisons, Mikuni set up to flat-slide
so we could pretty much have equivalents but nobody was the same
on the flat-slide.
                    - Mike

[noisymilk]

Very encouraging. This is the carb I have been considering as well.

Have never been successful getting the VM28 to hold steady idle. I hope this one does better....brand new can't hurt.

[Leonard]

That much difference, huh? any thoughts on jetting; I'm between 2500' & 3500' during my commute to work. As I rebuild my Sixty-5 after the wreck I thought of the flat-slide, the mid-fifties English exhaust, K&N, better oil pumps, H-D clutch springs, just basically keep the innards stock; any thoughts?

The high capacity oil pumps aren't any better and with the set up you discribe not needed. 

[1Blackwolf1]

  What's wrong with high pressure oil pumps?  Just curious...Will.

[Rick O'Shea]

Thanks guys. So you're pretty sure about oil pumps Leonard? Heard they drop the temp @ the head substantially & I hope to get many miles out of this bike before the first rebuild. But if it's not necessary....

[baird4444]

In theory they should be the perfect answer. More oil to the head for more cooling, in theory...     It was posted LONG ago either here or another group that in the real world even the stock pumps will "lift" and not pump when they are maxed at higher rev's or thicker oil conditions. ( another reason for the warm up... )  I don't remember if it had to do with smaller oil journals but seems to be it. We are not limited by the pump's capacity but by the oilways. The lifting is like a relief or pop-off.   
    all from a cloudy memory that tells me don't bother - Mike

[Leonard]

Nothing "wrong" with the high capacity pumps just not needed, and in my case oil usage increased dramatically.  Usage, not burning, not sure what happened to it maybe getting blown out. 
In any case the stock oil pumps are sufficient unless you do some engine mods.  The big selling point is the cooling and I think we tend to forget how these bikes get used in India and they have gotten by for years with the stock pumps.
   

[baird4444]

Nothing "wrong" with the high capacity pumps just not needed, and in my case oil usage increased dramatically.  Usage, not burning, not sure what happened to it maybe getting blown out.  In any case the stock oil pumps are sufficient unless you do some engine mods.  The big selling point is the cooling and I think we tend to forget how these bikes get used in India and they have gotten by for years with the stock pumps.  

But we are Americans Leonard. It seems like all to often we can take a simple
and efficient design; make it bigger and better till it blows up.
   Then we demand to know why...  somebody has to be blamed...

[ace.cafe]

I generally recommend that the hi-volume oil pumps be fitted when you change to a roller big end bearing on the con-rod.
With the floating bush OEM big end bearing, the stock pumps generally do fine.
The roller big end likes more oil delivery, and roller bearings don't build up oil pressure like plain bearings do. So, do the hi-vol pumps when you change the big end to a roller.

Regarding the carb, the flat slides do work better than the round slides, and the 30mm will do a little better on full-throttle too. Fuel economy will decrease some. I think you'll like it.

[Rick O'Shea]

Thanks ace, helpful as always. Good luck with the "V" project; i'll be watching.

[jest2dogs]

I have the 3 HD clutch springs, 18t countershaft sprocket, Samrat pushrods, basic electronic ignition, Amal 30mm carb, Indian short silencer and pipe, KB air filter and a new maintenance free battery. Oh, and my sprag is acting up. I had the high flow oil pumps but removed them. My oil consumption went up considerably when I had them in. The new ignition removes the "bark" of the exhaust. Instead it just seems loud all the time. That's all I intend to do to improve performance of the cast iron 500 I have (Classic 2006).

-Jesse

[single]

I am not disputing any one here,especially an actual experience.My '99 did not use any oil to speak of before the hi-volume pumps went  in,and it still doesn't.Of course,I do not know that they did any good,either.I do intend to upgrade the bottom end,so maybe a good thing to get done.For me.

[Rick Sperko]

Absofrikenlutely.

I always wanted to know how to spell that.

I went with a 32mm flat slide and had a huge improvement. I think until I add the Ace performance parts, I have more carb than I need and the 30mm would be just as good.

-Rick