Recant Disavow and Renounce...I say

[Greencan]

So whatever you have in mind with altering the air / fuel mix you will need to alter the airflow to within the air-box (eg holes), before undertaking any alterations within the carburetors themselves as the replacement air filter alone isn't enough to warrant any carburetor modifications.

I guess if different 'internals' are being offered for 1100 carburetors then this modifications can work...but I think a visit to your friendly motorcycle shop who has a dyno to begin with would be in order...interested to hear how you get on

The above cited remarks (from another thread), are that of my own and if I am truthful, pretty much based on...assumption .

It occurred to me the other evening while I shared a port or two with AJ1300 from over the back fence as we pondered the wonderments within the tupperware of my leaking ST1100 over the shed floor (yet again ), and chatting about air filters, air boxes  and power that I might well have got...(no actually), the wrong end of the stick . Ya see, AJ while talking about the randomness of components that go into the making of an assembly line engine caused me to remember my Dad's bog standard 1969 HT 161c.i. Service Station ute. It was everybody's  abused 'gofa' and was often referred to as "the Wednesday Car". Whatever, but it consistently outperformed my  186S HG ute and to a person, all commented of its remarkable "get up and go". I know why, because I spent the first 12 months of my Apprenticeship spending almost every hour of that year measuring, weighing , balancing, and recording most of the internals that comprised in making up DeHavilland and Lycoming internal combustion engines.

What my Neighbour from over the fence was reminding me of was if by chance a factory got all those components in harmony, you got a "Wednesday engine", a "cracker".
So Gentleman I recant, disavow, and renounce my assumptive remarks and return to the real world, and present to you Fellow ST Owners and DIY's the following two (2), You Tube vids that put it so well and, might well be a timely warning for you 1300 pilots.

Mighty Car Mods - POD Filters Mythbusted

Cold Air Intakes Mythbusted (Turbo)

Ciao, the can :)

[saaz]

ST11s have been modified, how far is really up to what you want. California spec models seem to respond to raising the needle a touch, and either richening the idle mixture by turing the pilot screw out a turn or so, or by putting in a bigger pilot jet that is used in other markets.

I have tried a few extra holes in the airbox lid but at least for mine some more major jetting changes would have been needed. And that was when it was running too rich mid range going by a dyno run. I just plugged the holes up with rubber grommets.  I may try freeing up one hole at a time and try it for a few weeks to see if there is a sweet spot

http://www.steinborn.org/st1100.html

[royst1100]

dont know ow many holes you put in but i did 4 only and on the sides not front. performance has improved ( not as in boy racer) but eliminated most of the flat spot i had. seems to pull better in lower gears 2up no flat spots

[Aj1300]

 :hi Dickie, I think we should get into some more Port and we might be able to solve the worlds problems, especially if we finish the whole barrell. Maybe we would have everyone on Sts.
Cheers Aj

[Greencan]

Hmmm...I am surprised I haven't got a 'bite' from the 1300 Guys who are advocates / users of the K&N air filters, other than AJ(I think he knows me too well) ...early days, early days

Saaz...when you say you bored holes in the airbox lid, you didn't mean the top did you? As this would mean you'd by-pass the filter all together...yes? I think Roy has the hang of it.

I am on record with Laurie and Baz saying that I believed that my blue / green ST has more get up and go because it has a K&N filter and the exhaust 'cans' have been liberated by a previous owner; than that of my green  / blue ST I rode to Blackheath.

 I now believe I was wrong.

I now think AJ's explanation is more plausible if not more likely and that the farkles on my blue / green ST do precisely faarr call to its performance advantage over my green / blue ST

Ciao, the can :)



 

[saaz]

Dick, if you drill on the outside of the filter in the top lid, no problems. Filter is not bypassed.  Up to 96 models there was a more aggressive cam used in most bikes (except California models). Post 96 the less aggressive cam was used in every model worldwide.  There is a touch more lift and duration with the earlier cam.  But some bikes just seem to go better for no known reason.  I have a vague recollection that the K&N filter may had added a bit of zip to mine, and the staintunes seemed to give a sharper response, but hard to say now I have gotten used to them.

 I may have to keep those standard exhausts just to swap around and do a scientific test with a standard air filter     I should get another dyno run done on the same dyno, as I have a run from when the bike was bog standard.  But from what I remember, it was not necessarily power differences I felt but more the subtle feel of how the bike responded.

[Greencan]

Arvo John et al...

While rummaging around the garden shed yesterday thinking that I may have another thermostat housing in amongst the assortment of ST1100 bits n bobs I came across this number...


Right side


Left side

This air box is from a U.S. spec 1100 that was brought into Oz in the mid 90's from California, and as far as I can tell this 'farkle' pretty much resembles the right up I recall reading about on the STOC forums soon after I got my bike...but here's the thing. 


Part of the anti-emission items that were required by some U.S. States

The original idea (as far as I can tell), of setting to work and boring holes all through the 1100 air box came out of the U.S...and I believe that it stemmed from owners there trying to get a bit more out of their bikes as a result of the 10BHP (or there about), less power that the Euro spec bikes.

Cheers Dick :)

[saaz]

Dick, with that amount of holes the carbs would need a complete rejet. I found that even doing too many smaller holes in the lid made the bike run worse.  Do you have the carbs that go with the airbox?  Doesn't mean to say that they were correctly jetted though.  I have reached some sense in my old age and don't want to play around that much anymore 

[Greencan]

Evenin' John et al...

Do you have the carbs that go with the airbox?

Jolly good question that...I have a complete carburettor set, but I don,t know if they were originally under this airbox...sorry :( (I know where you were going with the question though )

I thought I'd post the pics as this air box has the 10 x 1" holes as cited in the original post I mentioned previously...I wont be putting it on anytime soon :)

Cheers Dick :)

[Biggles]

I thought I'd post the pics as this air box has the 10 x 1" holes as cited in the original post I mentioned previously...I wont be putting it on anytime soon :)

The things people with a hole saw do to improve on the designs scientifically developed by engineers!

[Diesel]

Sounds to me that if 'the Can' and Saaz owned Boeing 747s - they'd try and stick funny little turned up winglets out there on the wing tips to improve lift, yaw and aero-efficiency - PREPOSTEROUS I SAY!!!!!

[Biggles]

they'd try and stick funny little turned up winglets out there on the wing tips to improve lift, yaw and aero-efficiency - PREPOSTEROUS I SAY!!!!!

but scientifically developed by engineers including Burt Rutan, a "home-built" experimenter.