YICS eliminator help.

Hello hello everyone. Quick question. I still was unable to get my bike to start without jumping up into the 5000's so I decided to install my YICS eliminator tool, hoping it might do something for me. Unfortunately I can't get anything now. So I need to know, once the tool is installed, would I need to lean out the engine? I assumed since it's getting less air, that would be the case, but I'm not so sure anymore. Any help would be appreciated. Thanks in advance!

Also my Seca and my 81 CB750 for fun

 

Installing the blanking tool will not affect the revs of your motor. It sounds like an air leak or stuck slide to me.

 

I suppose I should clarify. My bike has never been able to start under it's own power without starting fluid and the choke on. It would rev high to about 5000rpms and I could play with it a little with the choke acting as the "throttle".

After installing the tool, I can't even get it to do that. Starting fluid makes it go for only as long as the fluid is being burned, about 1.5 seconds XP

Thanks for the response friend! And you probably answered the question, I'm just not sure if I explained correctly the first time

 

Air leak (shaft seals, intakes) or the butterflies not seating correctly, bind in throttle linkage.

If you did a carb clean without taking the carbs off the rack and dipped them in a chemical carb cleaner, the throttle shaft seals and fuel rail seals are toast. After 30 years they were almost toast anyway.

Make sure you perform a good cluck test and verify the butterflies are seated correct by shining a light from the back of the the carb throat. You should see very little, if any light at all.

Make sure the floats are wet set and a real good bench sync is performed. Of course, this is all mute if your valve clearances are not in spec.

Introduction of excess air (i.e. air leak) will cause the carb to think you are opening the throttle, which increases fuel flow resulting in the engine revving to 5000 rpm with the throttle closed.

Happens to most of us with the first carb cleaning...

hope this helps
(edit)
after you last post, it sounds like the carbs need to be thoroughly cleaned and rebuilt.

 

Thanks for the response! I actually did take the carbs apart like 5 separate times haha, though I never dipped them in anything. I performed the clunk test and it checked out fine. I'm certain the air leak is in my boots unfortunately. I've tried everything with them to ensure they were leak-proof, but they might be it. I just wish I could find them for less than $300, it's just ridiculous if you ask me.

Thanks again for the help

 

Thanks for the response! I actually did take the carbs apart like 5 separate times haha, though I never dipped them in anything. I performed the clunk test and it checked out fine. I'm certain the air leak is in my boots unfortunately. I've tried everything with them to ensure they were leak-proof, but they might be it. I just wish I could find them for less than $300, it's just ridiculous if you ask me.

Thanks again for the help

 

You can "repair" the intake boots by slipping bicycle inner-tube pieces, along with rubber cement, over them.

Did you remove your "Pilot" screw (idle fuel-air adjust) clean it's well, put a wire thru the "transfer ports" at the throttle blade, blast carb cleaner and compressed air thru, and replace the rubber "O" rings - as the Pilot circuit must be completely clean-and-clear.

+1 on new throttle shaft seals.

Valves in spec - compression test - post your ##'s

 

Lol I just looked up randomly and found a used pair for $93.00. Just need the O-rings now

 

I'll have to look for the transfer port, not sure what that is exactly. And everything else I did. I'll have to check the throttle shaft seals as it seems to be a pretty common problem. Where are they located again? Thanks everyone.

 

Also I was just screwing around and somehow managed to get it to start the way it did before. So now I can get it to rev to 5000rpms and then it tries to idle at like 300 or so but of course dies. I'm trying to mess around with the butterfly valves just to see if I can get it to idle a bit higher, at least until I finish my homemade manometer

 

not trying to be sarcastic, but you cannot boil an egg without water.

Simply put, there is an order to getting these bikes to run correctly.

First is valve clearances. If they are not in spec nothing else is going to matter.

Next is the carbs. If the carbs are clean and renewed correctly, with the floats wet set to spec and the carb set bench sync'ed, the bike should idle fine.

That is assuming new spark plugs, a/f screws turned out 2 1/2 turns from bottom, fully charged good battery, stock filter and exhaust and properly operating petcok with fresh gasoline.

The vacuum sync and colortune are the final "fine" tuning of the motor.

These bikes are like a monopoly game, try and take a shortcut and boom, back to the beginning you go, do not collect $200....

Why don't you bring us all up to speed with exactly what you done, tested, in order and your results.

And before you try to remove the intakes from the motor, be aware that 95% of the time the stud breaks off and then you will feel real phucked. So be sure that is a problem before attempting to remove them. RTV silicone and bicycle tire tube is usually a sufficient repair so you might want to look into that more first.

 

The transfer ports are where the butterfly touches the carb housing, near the Pilot port. Top surface inside.
The throttle shaft seals are where the butterfly shafts pass thru the carb body - - requires removal of the staked screws on the butterfly and complete carb rack dismantling (oh, the joy !!)

Your carbs could be way, way out of sync.
You can make a simple sync tool in minutes - -

http://xjbikes.com/Forums/viewtopic/t=2 ... +sync.html

 

I've taken apart the carbs multiple times (like 5 times) because everytime I thought maybe tey weren't clean enough, although I never disassembled them from the rack. I checked my valved clearance although I'm not entirely sure if I did it correctly, it may be my problem. I also bench synced the carbs and checked the float levels which are good. I had to take the carbs of so many times that I ended up breaking 2 of the intake boots so that may have an air leak, even though I've used rubber cement and gasket sealer all around the affected area. I changed the oil and plugs and I'm getting a good spark too. Oh, and of course the YICS eliminator is installed. That's pretty much all I can think of at te moment

 

ok...now you need to slow down and refrain from playing whack a mole.
There are enough references on this site to show you how to check your valve clearances and correct them if they are out of spec.
Also, you may want to perform a compression test on the engine before doing anything else. If the valves are way out of spec, the bike will run fine all the way up to the point it won't. Another word, no warning.
I am afraid you really need to break the carbs off the rack and replace the throttle shaft seals and the fuel rail seals,
You mentioned you cleaned the carbs, did you remove the emulsion tube and clean that as well? Did you verify that all the carbs have the correct jets and visually inspect that a PO hadn't drilled them out?

It is a tiresome task to be methodical and to have the patience to restore one of the bikes to running order, but once you get there you can enjoy your bike for thousands upon thousands of miles with just normal maintenance.

Hope this helps

 

For some reason it makes me feel a little better haha. I THOROUGHLY cleaned those bad boys haha. I mean I soaked them and then took a twist tie and got every nook and cranny of those emulsion tubes. I'll order some seals right now haha. I'm not certain about the jets either, how would I check? And I certainly hope you're right. I've been dying to ride it since I got it like 6 months ago

 

The YICS eliminator is a joke.

It's not all that effective for tuning (doesn't seal as needed) and leaving it in long-term will only cause you issues. The bike was originally set up for YICS; blocking it is a tuning device. Blocking it permanently will only compromise performance and fuel economy and complicate your tuning efforts.

Bruce B and others have told you what needs to happen. You need to get the valves in spec (and we both know they aren't) then properly service the carbs (which has not been done) THEN you work on sync and mixture tuning.

Or continue to fight with it. Progress doesn't seem to be being made; so how long you pound your head against the wall is up to you. Quit screwing around and do it in order and do it right;

or continue the battle. (You won't win at this rate.)

 

Yea I had to step back from it for a while and I'm just now getting back into it. I'm looking for seals right now. I'll definitely have to recheck valve clearance after a few youtube videos. I need to be able to see things.

 

Valve clearances: http://xjbikes.com/Forums/viewtopic/t=14827.html

Part Deux: http://xjbikes.com/Forums/viewtopic/t=29209.html

Step-by-step, with pics.

 

So I messaged chacal about the seals and I didn't find anything about fuel rail seals. Is there another name for them? Thanks.

 

no, but Chacal will give you all the information you will need.

 

Thank you Sir, I appreciate it.

 

So I'm following your instructions to check vales with an insulated wire (awesome btw, thanks), and I noticed my shim has no numbers, so I can only assume they were put in incorrectly and worn down, where would I go from here? How would I be able to measure the shims? I assume I'd have to get a special tool of some sort and them measure them or something? Also, do I need to take shims out one at a time or can I just keep rotating the crank and taking the ones I need out without putting them back in? I figured I'd ask before continuing. Thanks in advance everyone! Finally getting work done!

 

Use something like this to measure the shims.

http://m.harborfreight.com/4-inch-digit ... 47256.html

You have to do them one by one. So yes put the shim back in after you measure and note the size. Move on to the next.

Don't forget to disconnect the battery before you do anything.

Good luck.

 

Thanks friend! I asked because autozone would measure them, but I don't wanna take 4 trips :/ I'll definitely look into that tool. Could be a good investment

Also! When I need to trade up, do I just make a thread posting my shims and requesting others? I'm not sure how the pool works, as I just heard of it. Thanks!

 

Okay, so 2 of my exhaust shims said 290 but when I measured them, they were 288. So from now on, these are 288's correct? Because in the manual it doesn't show that increment on the chart, so what would I do then?

As it stands now, I can swap 2 of my shims to get the right measurement, at least that's what I've come up with.

Lastly, and I realize this will sounds stupid, but with the feeler gauges it would say in .102 mm -.105 mm, I could get the tip of the feeler gauge in until it reached a certain point (I assume the .105 portion), but the chart gives me shim numbers until .10 mm then skips to .11 mm does this count as in spec considering there is no indicator as what to do between thos number?

Sorry about all the questions, but I really need to not mess this up. Thanks everyone!

 

that shim is still a 290.
do i understand that you have a feeler gauge with two numbers on it?
what are you using that measures mm out to three places?
take your measuring tool and measure that feeler gauge

 

Better yet; buy metric feeler gauges. He's using an SAE set of go/no-go feeler gauges that are stamped with metric equivalents.

 

I see.. But if it's not the correct size, why do other people still want them? Yes, just 2 measurements. There is a portion of each gauge that's about a half inch long and it's the first size, and then there'es a line that separates it from the rest which I'd imagine is the other size.

So what would I do first sizes that aren't covered by the graph (as per my example earlier).

Thanks for the input!

 

That makes perfect sense haha. So again, if shims change size, but they stay the same number, aren't they useless? I'm curious about this, and also about my previous example Thanks

 

By the time a shim is worn enough to change size, it's been in the engine for far, far, far too long. It is possible that a PO ground that shim in order to reuse it, and got it a bit undersize. The numbers being missing leads me to beleive that is exactly what was done.

I think your confusion about the chart is the degree to which you are measuring. Yamaha calls for acuracy to 0.01mm (an industry standard for motorcycles). There is no need to measure to the next decimal place in order to get the valve clearances in spec.

Read the clearance.
Read the shim.
Read the chart and put that shim in.
Done.

The reason that your question comes up is because of the feeler gauges that you are using. Metric feeler gauges measure out to the hundredths place, which is all you need to work on a metric motorcycle.

As Polock said, your measured 288 counts as being a 290 for the purpose of finding the next size shim that you need.

 

Wow, that makes perfect sense, I was definitely over thinking it! I'm gonna pick up a set of metric gauges (my third set of gauges) and I understand


Ohh, so because it's not the right size, I would still replace with a 290 despite it being 288? I'm sorry if I'm not getting it this second, It's a little late, er, early. Thanks again Sir, you cleared up a lot for me so far!

 

Your "288" is a 290. You would replace it with whatever size you need for that valve; the next size down is a 285.

"Smart Feelers" (go/no-go gauges) are a gimmick at best; they don't belong in a serious mechanic's tool box. Definitely find a metric feeler set and do it right. K-D Tools' #2274 are still widely available.

 

Thanks again. I figured something was off After this I'm moving on to my old identical pair of mikuni's that came with my bike again. They're clean, but they're just a spare set; I've tried separating them to get to practice getting to the throttle shaft seals. Damn those rail screws are ridiculous though. I can't get them for the life of me

 

Are you using a JIS screwdriver? You need to be, especially on the carbs. IF you don't have a set then use an impact driver. The smaller of the two phillips bits will fit a JIS screwhead, and the impact will loosen the screw without damaging it.

 

if those feelers were metric and were the right sizes, they would be the cats a$$

 

I'm currently working on getting jis screwdrivers and an impact driver. I'm not very familiar with an impact driver so I'll need to research them a bit (gotta buy all my tools now). Also I can't seem to get good metric feeler gauges anywhere in my town, may have to order them.

Thanks again everyone, I know that when I get it running, you'll be the first to know! I had to step away for a bit there, but I'm back in the zone.

 

I broke 'em free!... Except one. I need to drill it out. Thankfully I have a spare set of the same model carbs I'm practicing on first Plus it'll give me a decent idea how bad the seals are, if they're around the same age in both carbs of course.

 

Once you know what size shims you need, PM me..... We do have a shim pool here.

I have a YICS. Tool too---- I don't use it either. It just here so I can show people what one is when we hold a carb clinic. I don't feel the need to use it.
Dave F

 

Awesome! I should have an answer on Thursday when my 3rd pair of feeler gauges (legit metric this time) arrive