Author Topic: Harris Scrambler gets 'S' cams  (Read 16680 times)

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boggy

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Reply #15 on: April 03, 2013, 12:50:41 am
Interesting how different these machines can run.  Jake, I have the 30mm PWK, same filter, and a baffled megaphone. I'm running a low 120's (can't recall exactly... 122? 123?) main and I'm STILL running a bit rich.  Needle in the highest notch.  Stock cams.  2007 AVL.  Although some black stuff is telling me I have a slight exhaust leak too where the engine/header meet so maybe that's that.

These cams sound like a worthwhile upgrade for sure.  Good luck with your tuning.
2007 AVL
2006 DRZ400SM


Bullet Whisperer

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Reply #16 on: April 03, 2013, 08:27:03 am
Just in case it has been forgotten, on the machine I tuned originally there was a steel ring [like a big, thick washer] in the exhaust port, between the head and exhaust pipe and the hole through it was very restrictive. I opened it out by approx. 4 mm diameter, if I remember right.
 B.W.


boggy

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Reply #17 on: April 03, 2013, 03:03:58 pm
Hey BW - Just so I'm clear (and if there is a thread explaining it just point me to it) You put the washer in there and even with drilling it out wider, you still have a much smaller exhaust port to header than stock?
2007 AVL
2006 DRZ400SM


Bullet Whisperer

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Reply #18 on: April 03, 2013, 07:29:14 pm
Hey BW - Just so I'm clear (and if there is a thread explaining it just point me to it) You put the washer in there and even with drilling it out wider, you still have a much smaller exhaust port to header than stock?
Hi Boggy,
 I only ever saw the one AVL engined bike in this respect and some minor work had been done already, before it came my way, but when I pulled the 'Freeflow' pipe [header pipe] off to get a look into the exhaust port, I noticed this steel ring, like a large washer stuck in between the head and the pipe end and the hole through it was way too small, so I enlarged it. I assumed [rightly or wrongly] that this was a part found on all these machines, if it is the case, it can easily be opened up for better breathing as it would be very restrictive if left alone. I was asked to leave the ports alone because it had to be a 'bolt on' kit that I was helping to develop, so they were left untouched.
 B.W.
« Last Edit: April 03, 2013, 07:31:40 pm by Bullet Whisperer »


boggy

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Reply #19 on: April 04, 2013, 01:26:17 am
OK, interesting.  Thanks.  Was curious if I was missing something on mine since it's wide open.
2007 AVL
2006 DRZ400SM


Adrian

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Reply #20 on: April 06, 2013, 12:17:36 am
The restrictive steel insert for the (otherwise) unrestricted Electra-X/AVL Classic pipe is an odd feature of the exhaust pipes supplied by Hitchcock's, which I am guessing is what our hosts sell.

This insert is not needed at all, just bin it or save it in the odds & ends box, and use a good smear of silicone RTV around the exhaust pipe flange, especially if you have opened out the exhaust port on the head.


Bill Harris

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Reply #21 on: April 07, 2013, 11:40:33 pm
I'm using the Royal Enfield Classic Exhaust System with the upswept adapter as supplied by nfieldgear.  On the end of the header pipe, the end that goes into the head, there's a steel washer welded over that open end.  This washer is there to provide a mating surface on the header for the exhaust gasket that's in the port.  The inside diameter of this washer is less than the diameter of the exhaust port and is restrictive.  I just opened up the inside diameter of this mating washer to the same size as the exhaust port.  There is enough of this washer left, after opening it up, to mate with the exhaust gasket and create a good exhaust seal.  That's what I did and it works okay for me.

Cheers,
Bill           


TejK

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Reply #22 on: June 17, 2013, 09:53:42 am
Thanks for sharing that, Bill. I am glad it worked out ok. So far as I know, all the other 'S' cam modified AVL machines ran ok 'on the dots', but retarding the inlet cam one tooth to avoid the piston isn't as drastic as the numbers [degrees] would have you believe. It will also take you further away from any likelihood of pinking [pinging] and aid top end performance a little, too.
 Good news indeed and I hope you continue to enjoy your machine !
 B.W.

Hi All,
I am new here though I have been reading up and following the post related to AVL 500 performance. I have a 2008 AVL 500 and live in Bangalore, India. I have till now just researched and have been reading up the wealth of knowledge and experience available on the forum, thanks to the number of experienced bullet lovers here.  I have been running my bike for a few years with :
1. A free flow exhaust ( w/out the small cat con pipe in the header)
2. A K&N RR1100 Air Filter (open to Air)
3. Blocked off re-circulation Valve on the exhaust port side of the head
4. A UCAL 33mm CV carb with a 140 main jet
5. A very thin (Calender paper) gasket at the Cylinder-Crankcase and at the Head-Cylinder faces
6. 18 tooth gearbox sprocket

The bike runs great and maxes out at 83MPH. It a fun bike however, ever since reading about the famous BW 'S' cams - I am looking source a pair for the bike. However, in India there are hardly any sources available for performance parts for the AVL. And the 'S' cams  are made to order part.

Since, there is mention of a few members receiving 'S' cams, I was wondering if you have had a batch made and may have a few available. (crossed fingers).

Tej




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Reply #23 on: June 17, 2013, 10:14:51 am
I think that makes 3 of us who still need a set of "S" cams! Send a pm to Paul, I am sure that he's got things planned for these cams :)

Tej - In order to get better top end and more crisp, you will have to dump the CV carb ;)


-Sanket


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Reply #24 on: June 18, 2013, 01:36:41 pm
I think that makes 3 of us who still need a set of "S" cams! Send a pm to Paul, I am sure that he's got things planned for these cams :)

-Sanket

Thanks for the interest ! I am sure I could get more made, but there is a minimum order of 6 sets required by the makers for the price to be anywhere like reasonable. Feel free to message me, any interested parties and we can take it from there ...
 B.W.


DanB

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Reply #25 on: June 22, 2013, 04:59:07 am
Count me in as well.  PM sent.
Suppose I were an idiot, and suppose I were a member of Congress; but I repeat myself. ... Mark Twain
2006 AVL Electra


Techmaven

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Reply #26 on: June 22, 2013, 08:00:20 pm
My exhaust opening has a brick red color to the buildup...very little buildup.


TejK

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Reply #27 on: July 03, 2013, 07:50:44 am
I think that makes 3 of us who still need a set of "S" cams! Send a pm to Paul, I am sure that he's got things planned for these cams :)

Tej - In order to get better top end and more crisp, you will have to dump the CV carb ;)


-Sanket

Hi Sanket,
I have sent him a PM for the cams. I maybe able to vouch for 2 sets depending on my friend's comfirmation. So counting you and DanB in that makes it another 2 so left with finding 2-3 more AVL nuts :)

Well, talking of carb I have a VM38 Mikuni sitting on the shelf unfortunately i seemed to have lost the original jets as couple of friends wanted to try it out and had swapped jets for leaner ones. Well, the carb has earned a dubious reputation as "Bike killer" :D ( mostly due to some weird needle jet which doesn't feature in any VM manual-guess this was jetted for a two-stroke ATV/snowmobile earlier). Well, it just sits there on the shelf smiling an evil grin tempting me to make it work but i just got the engine rebuilt so it will have to wait for other unsuspecting nuts who want to try it out despite my advise not to and fry their pistons etc !

Cheers,
Tej


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Reply #28 on: July 03, 2013, 08:33:36 am
That's great! Even a friend of mine wants a set.

About the carb -- A VM38?! Paul did mention that some of his machines run on 38mm carbs but our stock head won't be able to take such big carbs. Basanti did use a 36mm flatslide but according to him the TM34 was stronger @ lower revs. With a 38mm carb, you'll need a 350ish size mainjet and 35 or bigger pilot. Not sure which needle and needle jet will work.

-Sanket


TejK

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Reply #29 on: July 03, 2013, 04:59:11 pm
Great - Let me get the reply from BW and we can take it forwad from there.

VM 38 is overkill and a killer for the engines a 32-34 carb flatslide/roundslide should be enough and the cams :)

I am happy with the CV carb - no bogging under heavy accelerations gives smooth acceleration from the low upto the mid range and with a 19 tooth sprocket i can cruise all day 2 up ( wifey ) at 90-100 kmph ( 55-60MPH) on state highway with relatively low traffic.

A friend of mine had the VM 34 and it used to foul up plugs till i had his bike for a week and after a few adjustments and a leaky rubber flange change - it works like a charm. But there's always need for the extra 2-3 horses so well let's see where his bike goes next.

Cheers

Goa - here I come :)