Pilot screw turns: the saga continues

[Guest]

Well while playing with float heights I realized I have an odd ball float valve needle. I noticed because It required to have the tang bent extra deep evidenced by needing to grab a different screwdiver because my precision didn’t have enough girth to bend it the rest of the way.
I compared it to the one next to it and the post had a different dimension. Slightly thinner and the top had a flat instead of being rounded off. There’s no springy-ness to it and the float tang made contact with the rim of the seat before I felt any resistance. Normally if you push down on the floats and let go quickly they’ll bounce but this one is flat. No boing.
Either it’s the wrong needle or it’s just clapped out.

so now the search for the best deal on needles and seats

so now I’m looking for good

 

[Guest]

Btw I checked the fuel height on that carb and while it ran the level kept rising in my gage until it was at the top of the bowl

 

[Tom R]

Well you’re on to something there with the float needle.... a hanging idle is evidence of a lean condition, though.... any vacuum leaks?
It sounds like you have the idle circuit fairly well understood.
I didn’t read the whole thread, but assuming you checked the valves already. Did you bench sync the throttle plates? I usually do it by holding the rack up to a light and adjusting visually by the sliver of light under the plate.

 

[Guest]

Another interesting observation i made is the floats measured different on either side. I guess I always figured they should be the same but maybe after getting taken apart a lot and handled they start to develop a lean.

Which side of bowl do your floats hang??!

 

[Guest]

Four new oem valves on the way, and I still have new orings for them from cycleorings.com. A reason i didn’t want to disturb the old valve seats is they didn’t want to come out at all. Should be interesting trying to pry them out now.

 

[Steve]

Another interesting observation i made is the floats measured different on either side. I guess I always figured they should be the same but maybe after getting taken apart a lot and handled they start to develop a lean.

Which side of bowl do your floats hang??!

When I rebuild a set of carbs, I always check both sides of the float and twist them until they are within 0.5mm of each other. In the case of mis-matched heights, the higher number is the one that will affect the fuel height. You have to think "upside down" on this. You adjust the float height while the carbs are upside down. What you are measuring is the distance from the carb body to the bottom of the float (when it's upright, in its normal position). Fuel will reach the float with the higher number first, and teh assembly will start rising. It's impossible within the constraints of the carb body and bowl, but in an extreme case, one float could be down far enough that it is just barely allowing the other float to get wet.

Four new oem valves on the way, and I still have new orings for them from cycleorings.com. A reason i didn’t want to disturb the old valve seats is they didn’t want to come out at all. Should be interesting trying to pry them out now.

One common thing I find in a set of carbs is that the o-rings on the inlet valves are often cracked. They are also rigid enough to be mis-identified as plastic, and that is what is keeping them in place. With your new needles and seats, don't be afraid to get physical pulling them out.

Did your new needles and seats come with filters? If not, see if your old ones will fit.

.

 

[Guest]

I sprung for the 1-3day expedited shipping for an extra $6 which in todays world is about the same as paying and then saying, “ here, have an extra $6 for no reason.” So I don’t have them yet. Hopefully before the weekend though. I’m so excited to hear this thing idle. I almost had it last night. My floats are adjusted down an extra 1.5mm so the bad valves took a little longer to leak and I got excited for a moment as I saw 1500rpm on the horizon and it actually sounded smooth. But alas, it began sputtering and I had to turn the idle screw back in.

sure will be nice hearing an idle from this bike.

btw I hope everyone’s appreciating my use paragraphs since i got my hands slapped earlier.

 

[cowboyup3371]

btw I hope everyone’s appreciating my use paragraphs since i got my hands slapped earlier.

I know I'm reading your threads more often

 

[Guest]

This bike is on hold until I can get parts next week. Until then I’ve started my rebuild of my vintage 1978 Yamaha IT175 engine. It’s the second time I’ve done this one in the last twenty years but this time it needs the crank rebuilt which I’m learning to do myself. Unfortunately, I’m already to a point where I’m waiting on parts for it as well. What am I gonna do if I don’t have a bike to wrench on for four hours after work every day lol?

 

[Guest]

Got my valve seats replaced. Idled lowest it’s been for about ten minutes of tuning then suddenly it started stalling again. Took them out and cleaned out all the passages but no luck. It seems too rich again. Last thing I did was lower the floats and test rode it. Midrange is suffering now, popping and struggling. WOT is great. Idle is no good. Gonna bring floats up closer to 22.4. They’re at 24 now. Maybe 23.4 and clean carbs for the upteenth time. I’m starting to wonder if it’s not my igniter malfunctioning when it gets to a certain temp??

 

[salty_monk]

Once they are properly clean... you shouldn't have to go back in there for cleaning again. Not unless you leave it standing for weeks.

Are the tips present (not broken off) on your air screws?

Are your diaphragms good (no pin holes).

Did you check that your floats actually do "float" in a jam jar of gas...

It looks like you're running Pods. Uni's are not the norm people go for here. Are you running a Dynojet kit? You're going to need a lot of changes from stock with that setup.

Ignition - not easy to check without another "known good" unit nearby. It's the ignitor box that goes out. There are some tests you can do but are not always conclusive. The fix is a Dyna 2000 on that model as you need the electronic advance. Someone posted a Czech source of ignitions that looked interesting just the other day...

 

[Guest]

Yes everything is in order. I used some different methods trying to clean the carbs trying to be thorough. I have not rushed. But crap keeps showing up inside the carbs mainly from my cleaning. Last time I soaked them i decided to blast them with baking soda too. It’s supposed to be water soluable and clean out easily. I washed them out with soapy water and blew them out with air. Then i sprayed tge dickens out of every passage with Berrymans, yet when I went in to replace the valve seats there was evidence of baking soda still in the carbs.
I find it amazing there was anything in them but I think the problem was I hadn’t removed the valve seats and screens because they were really stuck in and I didn’t want to damage them. I tore them up pretty bad this week putting in new and found quite abit of stuff trapped behind them.

just goes to show, people, there are no shortcuts when it comes to cleaning these carbs. Everything must come off. I thought I was being thorough and I spent a ton of time soaking and spraying but because I didn’t want to spend $140 on valve seats because they wouldn’t come out nicely, I’m now sitting here frustrated and facing yet another complete tear down and soak. The good thing is I can put these together in my sleep now.

The way it was running great and then suddenly bad like a switch had been flipped tells me something new has become dislodged and is plugging a passage.

I have cleaned plenty of different carbs in my day but these BS32’s have got to be the finickiest.

 

[Steve]

Gonna bring floats up closer to 22.4. They’re at 24 now. Maybe 23.4 and clean carbs for the upteenth time.

If the specified range is 22.4 ?1.0mm, why do you have them set to 24? Especially since that higher number will make the carbs leaner? When you change them, set them to about 22.0mm. Still well within the range, but slightly on the richer side.

Yes everything is in order. I used some different methods trying to clean the carbs trying to be thorough. I have not rushed. But crap keeps showing up inside the carbs mainly from my cleaning. Last time I soaked them i decided to blast them with baking soda too. It’s supposed to be water soluable and clean out easily. I washed them out with soapy water and blew them out with air. Then i sprayed tge dickens out of every passage with Berrymans, yet when I went in to replace the valve seats there was evidence of baking soda still in the carbs.
I find it amazing there was anything in them but I think the problem was I hadn’t removed the valve seats and screens because they were really stuck in and I didn’t want to damage them. I tore them up pretty bad this week putting in new and found quite abit of stuff trapped behind them.

just goes to show, people, there are no shortcuts when it comes to cleaning these carbs. Everything must come off. I thought I was being thorough and I spent a ton of time soaking and spraying but because I didn’t want to spend $140 on valve seats because they wouldn’t come out nicely, I’m now sitting here frustrated and facing yet another complete tear down and soak. The good thing is I can put these together in my sleep now.

The way it was running great and then suddenly bad like a switch had been flipped tells me something new has become dislodged and is plugging a passage.

I have cleaned plenty of different carbs in my day but these BS32’s have got to be the finickiest.

"Several methods" might be OK, as long as at least one of them is the proper way.

As you have found, every shortcut taken is merely an opportunity to do it over and do it RIGHT.

No need to spend all that money on inlet valves. Good-quality units are available for about $10 each.

Maybe it's because I have done so many, but I would rather do Suzuki's BS32 carbs than just about any other.

.

 

[Guest]

Where are you finding valves for $10?! They’re obviously not oem? I had non oem in there and the needle springs were worn out. I wouldn’t buy anything but oem.

as far as fliat height. Ive found 22.4 to be too high on my carbs. Like I said I’m too rich. Setting them to 24 was done after finding 22.4 too rich at idle and not being able to get an adjustment from the pilot screws.

When im on the needle it’s obviously too lean now. Before this session of tuning the needle was great which tells me that float height is to blame since it’s all that’s different. After I bring them up a bit and the needle feels better on the test run, I’m going to be down to only being able to adjust the pilot screws. I have to tear down and clean one more time and if idle is still stalling out I might have to give up on having a good idle.

 

[Guest]

this is a vid of the result of five hours of soaking and cleaning...again. I?m slowly turning out the idle speed trying to get it lower. Nothing happens until a point where it stalls. I?m hoping having you hear and see it you might have somebideas for me.
just to recap:
carbs soaked and blown clean probably six times now
ALL orings replaced
new valve seart and needle
pod filters and dynojets kit ( in video I?m tuning without filters on)
needle on 4th down
124 main rest is stock
Idle fuel screws at approx 1-1/2 out
No vacuum leaks - wd40 tested
valves have been adjusted
I?m sure someone will think of something im forgetting that I?ve also done

 

[Guest]

After sleeping on it I’m on the opinion that I’m actually too lean? That’s really the thing I’m having trouble identifying. What doesn’t make sense to me is when I pull my plugs they all look different. One and two almost look like they have gas on them. 1,2, and 4 have ok coloring. #3 is getting black.
btw compression is same on all cylinders 150
another thing that confuses me is the lack of change when I’m turning the idle fuel screws. I can make it die similar to the video but there’s no sweet spot where the idle improves. It just sounds flat all the time. It’s not necessary to have the filters on to get it to idle is it. I know it make a slight difference in the end but to start and get it in the ball park? I’ve tried either way before and not seen a difference.

 

[Guest]

Another thing. I have replaced everything rubber on them short of the diaphragms and the choke caps.
I never hear anyone talk about replacing the choke caps. I assume it’s because when the choke is off the plunger closes the system off not the choke caps. Is this correct?

 

[Steve]

Where are you finding valves for $10?! They’re obviously not oem? I had non oem in there and the needle springs were worn out. I wouldn’t buy anything but oem.

as far as fliat height. Ive found 22.4 to be too high on my carbs. Like I said I’m too rich. Setting them to 24 was done after finding 22.4 too rich at idle and not being able to get an adjustment from the pilot screws.

When im on the needle it’s obviously too lean now. Before this session of tuning the needle was great which tells me that float height is to blame since it’s all that’s different. After I bring them up a bit and the needle feels better on the test run, I’m going to be down to only being able to adjust the pilot screws. I have to tear down and clean one more time and if idle is still stalling out I might have to give up on having a good idle.

You are correct, they are not OEM. However, I have used several sets of them and have had absolutely no problems. If you choose to stay with OEM, it's strictly your choice, I can't force it.

Have you checked the actual fuel level with a clear tube outside the carb while the bike is running? That will help establish a proper baseline. When you have your baseline established, you can then start to adjust your jetting.

After sleeping on it I’m on the opinion that I’m actually too lean? That’s really the thing I’m having trouble identifying. What doesn’t make sense to me is when I pull my plugs they all look different. One and two almost look like they have gas on them. 1,2, and 4 have ok coloring. #3 is getting black.

Big question here is ... how are you numbering your cylinders? They are numbered from left to right, as you sit on the bike. #1 is under your clutch hand, #4 is under your throttle hand. It is more common for #2 to run rich, but that is an indicator that the petcock diaphragm is leaking, allowing fuel to go straight to #2 cylinder, bypassing the carb. Your "#3" running rich shows those symptoms, and could indicate improper numbering.

Another thing. I have replaced everything rubber on them short of the diaphragms and the choke caps.
I never hear anyone talk about replacing the choke caps. I assume it’s because when the choke is off the plunger closes the system off not the choke caps. Is this correct?

Correct. The cap on the "choke" is just a dust cover. There are two items that close off the system. The plunger body covers the air passage and the rubber seal around the tip closes off the fuel port.

.

 

[Guest]

You are correct, they are not OEM. However, I have used several sets of them and have had absolutely no problems. If you choose to stay with OEM, it's strictly your choice, I can't force it.T
Ordinarily I would get the best deal I can, however, after fighting this problem for so long I can't afford to risk throwing inferior parts at this thing. I want to know it's good. That being said, I did have one needle that did not support the weight of the float like it should so I used one of the old good needles. The only needle that failed before was an aftermarket. So I have three good spares - well technically two. Not sure if Partzilla will accept a return on that needle or if it's even worth returning.

Have you checked the actual fuel level with a clear tube outside the carb while the bike is running? That will help establish a proper baseline. When you have your baseline established, you can then start to adjust your jetting.
I have. Not this time around, but I was doing that prior to this last rebuild. I actually purchased a 5mm x 0.5 threading die with the intentions of making my own adapters. I know you can get adapter gauges online for about $8, but I'm a machine mechanic and I figure it never hurts to have another oddball tool in my kit to avoid that Saturday night frustration finding out I need it and it's not sold regularly in stores. I'll just need to pickup some 3/16" rod drill a hole through it, thread one end, bend it, and clamp a tube on. It would be nice to have four made up because filling up the float bowls and draining them after every single one is not what I call fun. So far checking this with a cobbled up hose clamped to the drain projection is sketchy at best. I can't be certain of my reading when it want's to drip at the slightest tug and I already had a scare when it popped off while the bike was hot and running! Not doing that again.


Big question here is ... how are you numbering your cylinders? They are numbered from left to right, as you sit on the bike. #1 is under your clutch hand, #4 is under your throttle hand. It is more common for #2 to run rich, but that is an indicator that the petcock diaphragm is leaking, allowing fuel to go straight to #2 cylinder, bypassing the carb. Your "#3" running rich shows those symptoms, and could indicate improper numbering.
I appreciate all suggestions because it probably is something stupid I'm not seeing which is why I need fresh eyes on this and I keep pestering the forum to help me. Fortunately, I understand basic inline four motorcycle cylinder numbers so, no, I have the numbers correct. 3 is black and dry. 1 and 2 are clean but appear to have wetness on them when I pull them (possibly just them before they fired on the compression stroke?). And 4 always looks great.


Correct. The cap on the "choke" is just a dust cover. There are two items that close off the system. The plunger body covers the air passage and the rubber seal around the tip closes off the fuel port.
ok, good. I'm tired of ordering parts to have to wait four weeks to get them.

.

As far as gauging the fuel levels; where do you look on the outside of the carb to measure from? the line made by the top edge of the float bowl? or do you picture where the gasket surface is behind the bowl flange? Can you check the middle carbs, 2 and 3, on the bowls of 1 or 2 if the bike is level?

Thanks for those that are helping me try to figure this out. I'm sorry if it seems to keep going on forever or if it seems like I don't get it somehow. I'm out there probably spending fifteen to twenty hours a week trying to get this right. I'm determined to figure it out. I do need some help though. Granted my methods are improving everytime I try it over and over, but it gets pretty frustrating when you think you got it nailed and nothing changes and you just hit a wall. Sometimes I wonder if I'm thinking about it TOO MUCH? lol

 

[Guest]

Evidence points toward a plugged idle circuit but we know that's not possible at this point. What do I have to work with here? float height and fuel screw? fuel screw has no effect. guess it'd have to be floats then right?

thinking out loud here. chime in when you ready to party.