XS Special test run

[mro]

I've delt with both BS34 II and III's and have had no problems with them on stock engines. Neither have I had to "triple clean" any. Have had to remove a few broken pilots tips tho, which was a pain until I made a tool to do it. Now they just pop right out. Did same with removing the float pins w/o having to worry about breaking off a post (thanks to Ken and XS11.com).
Both tools worked on my flat slides too.
I've not taken sides about performance gains or not using newer style carbs and won't until I try it myself or one of you guys post some before and after dyno sheets.


mro

[olebiker]

Originally posted by TopCatGr58
Hey Prof,


Mine pops a fair amount during heavy engine braking, but I'm usually doing that from 7krpm while running the twisties! I just think of it as Godzilla Growling! When I'm on the throttle it runs very strong to redline and beyond if I wanted to push it!

Watch your plugs, and as long as they have decent color, and you know you don't have any vacuum leaks, then enjoy!
T.C.

I believe that a well tuned engine should have some gentle pops on deceleration. Ever watch Nascar those are some highly tuned engines. It is just some unburned fuel cooking off in the exhausts.

[oldman prof]

Ok, could'nt wait for the week-end,pulled the carbs last night.No.1&3 were at about 1/2 to1 turn out,no.2 was just about closed and I don't know no.4 yet because the idiot who drilled out the plugs ,drilled about 3-4mm into the top of the screw and wrecked the slot or he tried to get it out and wrecked it,sorry no pics yet but it was dark , my phone does not work so well in the dark,but I will have some on monday morning.

[pggg]

From mro - "I've not taken sides about performance gains or not using newer style carbs and won't until I try it myself or one of you guys post some before and after dyno sheets."


Hi mro, nah, there's no 'sides' to take, unlike some, the scotsman and the kiwi don't claim themselves as self-professed experts, we just know good carbs improve the bike...

[AlanB]

Hi Guys,

I'll probably try putting these in context in their own post, if I can find a way of getting a better looking copy, but this is the faded old summary sheet off of my shop wall;

For reference, the bike made about 70 bhp on the SG carbs, (as did a couple of other XS11s!) and about the same on "safe" (rich!) guestimate jetting on the Slingshots. During the runs we saw as much as 95 horse, but with vicious dips and troughs. We settled for 90 and smooth progressions.




If anyone doubts how useful Dyno runs are for a non-stock bike, you may be able to see the answer at the top of the sheet. The needle setting is quoted as "#1.5"....ie, position one, plus a shim washer equal to half a groove. It would be difficult to set carbs that closely on the road.........

Hope this helps!

AlanB

[oldman prof]

Well I finaly got the @#$&* thing out,I had to grind the ally done to the level of the screw then use a 1.5 mm cutting disc to cut another slot, even then I had to put a vice grip on a screwdriver to get the grip to turn it out.Most of the thread and the tip is still safe.I still think there sould be a law against some people getting near tools.I know to up the fuel (richer) you turn the pilot out but I'm looking the starting point i.e. how many turns out,I've seen the thread, I've searched but I can't seem to find it.

[mro]

I like to start em 1 1/4 turns out when there's stock air box/exhaust. Wind up 1 1/2 to just over two when done.
On a bike with pod filters might start at two tho if has stock jetting.


mro

[mro]

Hi pggg...

Guess I'm getting old, "unlike some" if I'm going to play football with a hornets nest want a decent bee suit on...


mro

[oldman prof]

Originally posted by mro
I like to start em 1 1/4 turns out when there's stock air box/exhaust. Wind up 1 1/2 to just over two when done.
On a bike with pod filters might start at two tho if has stock jetting.


mro

Good morning from a cold,wet and windy Cape Town this morning,I managed to fit carbs Friday pm , she started easyer,idled better but when I felt no.2 header still cold at start up,I dropped everything just there, decided to start again in the morning and our "spring" turned into winter the whole weekend.I started the carbs at 2 turns,I will try again when the weather clears,and my jets are 110's,I hav'nt tested yet.I do'nt mind wet but I'm to old for cold rain and an icey wind.
I'll let you know when it clears
Anthony

[AlanB]

Hi Prof,

No2?.... Are you sure that the Vac advance line is plugged into the correct place on the body of No2?... and that it has no leaks?
I might cap off the port on the carb body, and give it a try.

No Vac advance won't hurt it.

If it will warm up on three, then swap a hot plug into the dead cylinder; might be enough to start it the first time!....... OLD trick!

AlanB

[oldman prof]

Yes thats the next thing , blocking that port but as I said to wet and windy,Will try it tonight, weather looks better.

[oldman prof]

I think I need to change to settings on the pilot screws, I started her last light,no change when I blocked off the port on the no.2 carb,but the no.2 cylinder is warming up much faster, and the reving is much smoother and more responsive when warm,so I'm getting it right,thanks to you guys,will play again the week -end,with 4 into 1 and pod filters I think I'm going in the right direction starting at 2 turns out,it can only get better now.
Thanx
Anthony

[oldman prof]

Ok I just had to use the black monster this morning and at two turns out the popping is not only less but its much quieter so this weekend I'm sure I'll get it right,thanks for the help gents,I'll let you know how it goes,I'm going to try to put a vid on photobucket monday morning.

[oldman prof]

Well this weekend saw me balance the carbs,no coughing or poping at start or idle but the no2 header is still cold untill I take the choke off,after that she runs lovely,I can live with that but would like to know the problem.

[AlanB]

Hi Prof,

Good work! Problems with no2 usually point to the vac line to the ignition having a leak somewhere; but I think you have been through all that?

Could just be that the choke is not working on no2; the enrichener jet lives down a tunnel in the bottom of the float bowl, the lowest point of the carb. They are often the first thing to block, and (Unless you know they are there!) you will never find 'em! There are some excellent pics on here somewhere; perhaps some of the clever guys will point you in the right direction!

Either some nifty work with a seriously short screwdriver to drop the bowl, or pull those carbs!

Good luck!

AlanB