question about pilot jets

I'm reviewing the strider thread on cleaning and overhauling the carbs. in section 4- carb. R&R(st1100) and in the paragraph "reasons to change the pilot and main jets", the author suggests that the initial number of turns out should be 1 7/8ths turns out. on my own bike I had the carb bowls off for, the first time ( p.o. might of had some reason to do this, but since I don't know who this is, I can't contact). this, just a few weeks ago and the pilot jets were All turned in all the way. since I was just intending to clean them, I returned the jets to the same position(s). up this point I never had reason to question the carb performance, other than I wasn't totally happy with the gas mileage. ( something that seemed at the time to be a fair trade off to get back into the good weather riding season.) now I'm going back in with the intention of cleaning and rebuilding the carb set. ( this will include new pilot jets this time. my question is- are my current p.jets in the wrong position, or is the quoted number of suggested turns out in error? the pilot jets are #38's and will be replaced with the same

There should be an external idle air mixture screw on the side of the carb. The pilot jet inside the bowl should be tightened down along with the main jet.

from some of the statements in your post it sounds like you're not really familiar with carb terminology. You're confusing pilot jets with the air mixture screw. I'd question why you want to clean and rebuild carbs unless there's a problem. And replacing pilot jets with the same diameter jet doesn't seem necessary, they don't wear out. Sounds like you're trying to make work for yourself where none is needed.

At first glance of the title, I thoughts you were asking jet pilots a question ;-)

Ok... I can see and understand your questions about the carburetor terminology.

For the ST1100, the Honda factory has it's very own terms that are DIFFERENT from the rest of the world. These are the "Honda terms": The adjustable screws at the bottom of the carbs, used to adjust the idle mixture, in Honda factory terms, are called "pilot screw's". The idle, lower rpm and transitional fuel circuits, in Honda terms, are called "slow speed circuit" and controlled by the "slow jet". The mid-range and upper rpm components are called "main jet", "needle jet holder" and "jet needle". I'm sure they paid engineer's and attorneys big bucks to fabricate Honda specific names for these components, for possible infringement rights. Even though Keihin is the supplier....

Now, in the real world, EVERYONE out in the field and most manufactures use the following terms : The adjustable screws at the bottom of the carbs are called "idle mixture screws". The idle, lower rpm and transitional circuits are called "pilot circuit" and is controlled by the "pilot jet". The mid-range and upper rpm components are called "main jet", "needle" and "emulsion tube".

So with this being said, and to avoid confusion, it would be best to use the terms: "idle mixture screws", "pilot jets", "main jet", "needle" and "emulsion tube". Everyone will know exactly what your referring to.

Now, getting back to that questionable and vague carburetor article you've been reading at ST-Riders.net...

I (the author) upgraded my bike (and many others) to the early non-emission Canadian spec's, hence the pilot jet and idle mixture screw changes. Followed by an idle drop tune and synch. It sounds like your removing the carbs again to rebuild your rebuild. I'm assuming you won't be performing the idle drop procedure when done. If your intentions are to re-use the oem #38 "pilot jets", then set all your "idle mixture screws" to 2 1/4 out from lightly seated. If upgrading to the #40 "pilot jet", set all the "idle mixture screws" at 2 turns out from lightly seated.

thank you Adam. things are much clearer now.( I WAS confused- and will probably be from time to time. but forewarned is forearmed, and I thank you all for that) for the record- first time around, I just cleaned, the clogged pilot jets ( first start up after sitting for 9months in my garage, with untreated fuel. the bike displayed symptoms of clogged pilot jets.. the work was to address this)..... when reassembled , the bike wouldn't start at all! I've come to the conclusion that the float valves were blocked by varnish/goo.( fuel supply up to that point has tested fine) I suspect the carb as a whole will be suffering from the same malaise)that's why I'm electing to replace float valves, seats, as well as pilot jets. ( the pilot jets being pretty cheap) the rest, I'll simply remove , clean , and reassemble. The pilots jets being fully seated in the carb, kinda threw me. Besides cleaning the goo/ varnish out of the carb body passages, I'm hoping that my MPG will improve as well. this brings up a question...is there a product that youall use to recondition the rubber of the throttle/diaphragm?

the_gr8t_waldo said:

thank you Adam. things are much clearer now.( I WAS confused- and will probably be from time to time. but forewarned is forearmed, and I thank you all for that) for the record- first time around, I just cleaned, the clogged pilot jets ( first start up after sitting for 9months in my garage, with untreated fuel. the bike displayed symptoms of clogged pilot jets.. the work was to address this)..... when reassembled , the bike wouldn't start at all! I've come to the conclusion that the float valves were blocked by varnish/goo.( fuel supply up to that point has tested fine) I suspect the carb as a whole will be suffering from the same malaise)that's why I'm electing to replace float valves, seats, as well as pilot jets. ( the pilot jets being pretty cheap) the rest, I'll simply remove , clean , and reassemble. The pilots jets being fully seated in the carb, kinda threw me. Besides cleaning the goo/ varnish out of the carb body passages, I'm hoping that my MPG will improve as well. this brings up a question...is there a product that youall use to recondition the rubber of the throttle/diaphragm?

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Good move with replacing all of the wear items inside the carbs. One less thing to worry about in the future. Remember that your rebuild will only be as good, with how you maintain those carbs afterwards.... Please use a GOOD fuel stabilizer. If the bike is gonna sit for any length of time, drain them.

As for reconditioning the diaphragms, there is no such thing. They are either in good condition, stretched out, or torn / pin holes. At $90-95 EACH, please be careful with them. DO NOT put any type of petroleum product on them. If stained or dirty, put them in the kitchen sink and wash them with warm soapy diluted water. Carefully clean them with a soft cloth and dry carefully. No compressed air. The plastic slides don't like carb cleaner either and can be easily melted / deformed from the harsh chemicals.

Best wishes on sorting out the carbs. If done right, you'll have a nice running ST with many years of trouble free service...

today I balanced the carbs. and everything's back and running fine. the carb cleaning went relatively well. the snorkel assembly was the most challenging! the only thing that I found is the float needles seemed to have a bit of resistance when I tried to remove- and no noticeable debris on the screens. but the replacements slipped right in with out any noticeable resistance. thank all for the help!

the_gr8t_waldo said:

the snorkel assembly was the most challenging!

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Too late for you, but remounting the snorkel assembly goes MUCH easier if it is attached to the carb bodies before the carbs are on the bike AND the carbs must be connected together only loosely, to allow movement of the individual carbs as you remount the assembly. After the snorkels are on, tighten up the carbs and mount on the bike.

Good job getting her back together and up to snuff. Yes, those snorkels / plenum assy can be really tricky! I did a set off a '97 for a local guy several weeks ago. Took me less than 5 minutes to assemble the top side of the carb bank. However, the set I did before that, took me a 1/2 hour. Your not alone...

Jrnyer said:

At first glance of the title, I thoughts you were asking jet pilots a question ;-)

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I was going to make this joke. Good thing someone did.

afrymoyer said:

warm soapy diluted water.

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I didn't know you could dilute water but you just expained it here - add soap. LOL Sorry, just could not resist.