DIY Shimming the carb needles.

[kamikaze]

Originally Posted by kamikaze

I was thinking about that too, anyone know off hand the measurements? I'm sure that hobby shop would have some nice stainless replacements

Originally Posted by Momaru

Urg, I know I posted 'em around here somewhere. I'll see if I can dig 'em up

Edit: Yep, here they are

Short answer, they're 4x18mm, 0.7 pitch. If you can't find 18mm, I'd get mostly 16mm and a few 20mm. See the above thread for why.

Just to update this, I finally got around to replacing these last night and the screws are not 18mm long. The factory screws are 16mm long and have captive washers that you can't remove from the OE screws, so you may need flat washers and lock washers as well. the 18mm screws may be good for the 3 on the left carb that have the extra brackets, but they are way too long for the other holes, even with washers.

[MikeBudd]

Originally Posted by kamikaze

Just to update this, I finally got around to replacing these last night and the screws are not 18mm long. The factory screws are 16mm long and have captive washers that you can't remove from the OE screws, so you may need flat washers and lock washers as well. the 18mm screws may be good for the 3 on the left carb that have the extra brackets, but they are way too long for the other holes, even with washers.

That is completely correct. I don't know where those other measurements came from (I'm on my phone and to lazy to check), but I do know that in this thread (approximately 2nd or 3rd page), it had the correct measurements. I replaced mine according to those.I bought like 100 bolts for 12 bucks because I couldn't find anything smaller, then replaced them with the ones in the fp jet kit. Now I have tons extra if people need them. I also have extra #3 washers if people can't find them. Close to 80 of them left :P

PS: if anyone is going to jet with FP don't buy the replacement screws as they provide some high quality ones in the kit.
Posted via Mobile Device

[Momaru]

Originally Posted by kamikaze

Just to update this, I finally got around to replacing these last night and the screws are not 18mm long. The factory screws are 16mm long and have captive washers that you can't remove from the OE screws, so you may need flat washers and lock washers as well. the 18mm screws may be good for the 3 on the left carb that have the extra brackets, but they are way too long for the other holes, even with washers.

Odd. My sincere apologies for the mislead then. That may be a between-year difference on the carbs (or mebbe my bike's just special). Mine were/are definitely 18mm (checked it on every screw at least twice on two different rulers) and the washers will fall off if I don't prevent them.

[MikeBudd]

Originally Posted by Momaru

Odd. My sincere apologies for the mislead then. That may be a between-year difference on the carbs (or mebbe my bike's just special). Mine were/are definitely 18mm (checked it on every screw at least twice on two different rulers) and the washers will fall off if I don't prevent them.

Mhmm. As far as I know they shouldn't be different. Did you measure just the bolt?

[Momaru]

Originally Posted by MikeBudd

Mhmm. As far as I know they shouldn't be different. Did you measure just the bolt?

Yup, just the threaded bit. If I include the head, it's 21mm. In retro-retrospect, mine may have been replaced by the previous owner, though he didn't mention any carb work on the top side, just new mains. Which, incidentally, had the bike running like shyte when I first got it...

[MikeBudd]

Originally Posted by Momaru

Yup, just the threaded bit. If I include the head, it's 21mm. In retro-retrospect, mine may have been replaced by the previous owner, though he didn't mention any carb work on the top side, just new mains. Which, incidentally, had the bike running like shyte when I first got it...

Interesting. Like @kamikaze if I put in 18mm bolts they don't fit. Do you have extra washers?

[Momaru]

Originally Posted by MikeBudd

Interesting. Like @kamikaze if I put in 18mm bolts they don't fit. Do you have extra washers?

Well... it's time I sat down for a slice of humble pie.

I've had the wrong set of screws. Been working off the sets I've got in my carb toolbox, which were pulled from the bike when I swapped out the screws a long while back. Now that I've found the real OEM carb screws the PO gave me, they're 14mm.

Not my day today, sorry about the mixup and misinformation all. I sincerely hope I haven't caused too many problems.

[kamikaze]

no worries. So the OE ones that you measured were 14mm, is that with the washers? on my OE screws there is a flat washer and a lock washer that don't come off, which just by eyeballing looked to be a couple mm.

[Mr.E]

Out of curiosity, how mandatory would you say the washers are? Going out in a couple of min to find screws. I already have about 4 or 5 screws in my carbs, and I'm pretty sure they're washerless because they were used to replace the screws I stripped. Also, I know they're the wrong size. I hope getting right size screws will make me feel better.

And I'm unshimming. My MPG took a huge hit and I feel like I have a flat spot. This is probably just because of unpropper mixing with the fuel and air, but if the bike ran fine (minus the long wait for start up) then I'll be fine returning to stock x-) lol

[kamikaze]

Originally Posted by Mr.E

Out of curiosity, how mandatory would you say the washers are? Going out in a couple of min to find screws. I already have about 4 or 5 screws in my carbs, and I'm pretty sure they're washerless because they were used to replace the screws I stripped. Also, I know they're the wrong size. I hope getting right size screws will make me feel better.

And I'm unshimming. My MPG took a huge hit and I feel like I have a flat spot. This is probably just because of unpropper mixing with the fuel and air, but if the bike ran fine (minus the long wait for start up) then I'll be fine returning to stock x-) lol

I just added another shim to mine (2 total now, stock can & removed snorkel) and I'll see how it runs this spring. I was pretty happy with 1 shim last summer on premium fuel, but there was still a little flat spot around 8-9k.

[Mr.E]

Im currently at 2 shims lol. I tried removing my snorkle, but the bike ran like crap. So much so that I called the buddy that helped remove it and went to put the snorkle back in that night lol. But every bike is different. I'm just taking the easy way out and putting it back to stock, which for me had no flat spots or anything x-)

[saxnbass]

Zach and I went down to 2 washers this weekend and we are both really liking it. We both have the snorkel removed as well. Pulls harder and smoother than with 3.

[oreX]

Originally Posted by saxnbass

Zach and I went down to 2 washers this weekend and we are both really liking it. We both have the snorkel removed as well. Pulls harder and smoother than with 3.

+1 to this.

I also think that three washers was killing the gas mileage.

[choneofakind]

Originally Posted by Mr.E

Out of curiosity, how mandatory would you say the washers are?

Not mandatory at all. My caps and bowls are held on with hex key screws and no washers on any of the 16 screws. No issues so far.

Although, I believe mine are also all M4x18 screws and I haven't had any issue with any of them. They just go through the holes and secure just fine... I followed Momaru's post on replacement screws also, and they worked out just fine for me.

The only screw I replaced that I did use the same washers on was the M5 screw that holds the throttle cable bracket on just because the oem screw is an M5x10, and I don't know how deep that hole is, so I figured it would just be easier to get a lock washer also and not worry about the depth of the hole.

[kamikaze]

Originally Posted by choneofakind

Not mandatory at all. My caps and bowls are held on with hex key screws and no washers on any of the 16 screws. No issues so far.

Although, I believe mine are also all M4x18 screws and I haven't had any issue with any of them. They just go through the holes and secure just fine... I followed Momaru's post on replacement screws also, and they worked out just fine for me.

The only screw I replaced that I did use the same washers on was the M5 screw that holds the throttle cable bracket on just because the oem screw is an M5x10, and I don't know how deep that hole is, so I figured it would just be easier to get a lock washer also and not worry about the depth of the hole.

when i put the 18mm screws in without washers they bottomed out in the 2 or 3 holes I tried them in. I think 16mm with washers, 14mm without would be a better fit.

[choneofakind]

There's no bottoms in the holes on mine. they just go straight through. Next time I have them off, I'll measure them. It's possible I used 14's instead of 18's. idk. lemme go check my recent posts. I remember posting about it.

[MikeBudd]

Originally Posted by Momaru

Well... it's time I sat down for a slice of humble pie.

I've had the wrong set of screws. Been working off the sets I've got in my carb toolbox, which were pulled from the bike when I swapped out the screws a long while back. Now that I've found the real OEM carb screws the PO gave me, they're 14mm.

Not my day today, sorry about the mixup and misinformation all. I sincerely hope I haven't caused too many problems.

Interesting, no harm done!

Originally Posted by kamikaze

I just added another shim to mine (2 total now, stock can & removed snorkel) and I'll see how it runs this spring. I was pretty happy with 1 shim last summer on premium fuel, but there was still a little flat spot around 8-9k.

This has absolutely no effect on how your bike runs and is just eating a hole in your wallet. TBH stick to the recommended 87 octane 91 RON.

Originally Posted by Mr.E

Im currently at 2 shims lol. I tried removing my snorkle, but the bike ran like crap. So much so that I called the buddy that helped remove it and went to put the snorkle back in that night lol. But every bike is different. I'm just taking the easy way out and putting it back to stock, which for me had no flat spots or anything x-)

Yea, one of my friend had exactly the same thing happen. Removed the snorkel and his bike turned into a piece of poo. Put it back in and works perfect :P Every bike is different!

Originally Posted by choneofakind

Not mandatory at all. My caps and bowls are held on with hex key screws and no washers on any of the 16 screws. No issues so far.

Although, I believe mine are also all M4x18 screws and I haven't had any issue with any of them. They just go through the holes and secure just fine... I followed Momaru's post on replacement screws also, and they worked out just fine for me.

The only screw I replaced that I did use the same washers on was the M5 screw that holds the throttle cable bracket on just because the oem screw is an M5x10, and I don't know how deep that hole is, so I figured it would just be easier to get a lock washer also and not worry about the depth of the hole.

Same here, I haven't been using washers (just the socket cap screws from factory pro), and everything has been fine.

That's strange. I'm pretty sure when I tried 18's they wouldn't bolt down as they were hitting the metal that is a couple millimetres after the end of the hole. that's weird.

I didn't even bother replacing that screw yet. I'd have to go out and buy another 100 pack from fastenal or something because I haven't been able to find a smaller one. I'll do it eventually. Taking off the throttle cable bracket is definitely much easier than removing the cables and having to re-adjust them every time.

[choneofakind]

Originally Posted by MikeBudd

That's strange. I'm pretty sure when I tried 18's they wouldn't bolt down as they were hitting the metal that is a couple millimetres after the end of the hole. that's weird.

I figured out the discrepancy! I used M4x16 screws, which work just fine without the washers on the bowls and caps.

http://www.ninjette.org/forums/showp...postcount=1358

M4x18!! geez chone come on. Losing it here

[MikeBudd]

Originally Posted by choneofakind

I figured out the discrepancy! I used M4x16 screws, which work just fine without the washers on the bowls and caps.

http://www.ninjette.org/forums/showp...postcount=1358

M4x18!! geez chone come on. Losing it here

That's hilarious

Good to know i'm not loosing my mind though. I was just about to go check my bolts, praying that I was not crazy.

[choneofakind]

No worries, I hopped on the crazy train so you all didn't have to!

m4x16 for sure work without any washers, and they seem to work fine even on the corners that have brackets on them. But I have a pre-gen, so the brackets may be different. idk. When in doubt, buy 1 screw in a couple sizes, and see which one works best!

[kamikaze]

Originally Posted by MikeBudd

This has absolutely no effect on how your bike runs and is just eating a hole in your wallet. TBH stick to the recommended 87 octane 91 RON.

Well, I beg to differ. after shimming the needles and pullin the snorkel it still ran like crap on 87. Started filling it with 91 and it ran much better, plus I get slightly better mileage.

[Steven250R]

Hey guys!

So ive read pretty half way through the entire thread and im planning on doing this to my 09 250R.

I live in the Bay Area and im planning to pick up some shims from the Radio Shack here in town.

I am also going to order a full exhaust, do an oil change, pull the snorkel out and throw some shims and figure out what works best for my setup.

I just wanted to say thanks for all the time and effort you guys put in, to give everybody a helping hand! Glad i joined the forum and will def post my results as soon as i gather all my parts together!

Thanks!

[choneofakind]

Welcome to the Forum @Steven250R! Introduce yourself in the new member section so we can all say hi and get to know a little about you

If you're going with a full exhaust (and I would suggest de-snorkeling as well) I would pick up some 100 Keihin jets, and test them out in comparison to the stock 98 Keihin main jets to make sure that you have the main jets correct. Then shim

[MikeBudd]

Originally Posted by kamikaze

Well, I beg to differ. after shimming the needles and pullin the snorkel it still ran like crap on 87. Started filling it with 91 and it ran much better, plus I get slightly better mileage.

Check out the video below. I'm not saying your wrong, but your experience doesn't equate when you look at what octane actually means and what higher octane does. Also refer to that thread for other info

Originally Posted by headshrink

This video explains octane in a very simple manner. It's not my video, but I thought I would share it with the community here. You may enjoy some of his other motorcycle videos too.

Link to original page on YouTube.

[kamikaze]

Originally Posted by MikeBudd

Check out the video below. I'm not saying your wrong, but your experience doesn't equate when you look at what octane actually means and what higher octane does. Also refer to that thread for other info

premium fuel is not just higher octane. some brands have no ethanol in their premium fuel, which I think makes a difference. Different additive packages as well.

either way, I've had good luck with it, and for the extra buck or 2 a tank, it's not exactly emptying my wallet.

[Alex]

Originally Posted by kamikaze

premium fuel is not just higher octane. some brands have no ethanol in their premium fuel, which I think makes a difference. Different additive packages as well.

Not so common here in the US. Companies are required by law to hit a minimum average company-wide for ethanol, and they can't remove it completely from premium and still meet those requirements. The additive packages are sometimes a bit different, though nothing so earthshattering that it makes any difference on an engine that is already working well.

[TnNinjaGirl]

I would think since our engines have high compression that they would run better on the 91 vs 87 anyways. Does the ignition timing adjust itself? If so the higher octane would help performance/fuel economy as well.

[Alex]

Not in this case. There are no knock sensors that would allow the timing to be adjusted at all, and while the compression ratio is nominally high, the small size of the cylinders and the non-aggressive valve timing result in a lower effective compression.

These engines truly run just fine on 87, and receive no benefits from a higher octane rating.

[MikeBudd]

Originally Posted by Alex

Not in this case. There are no knock sensors that would allow the timing to be adjusted at all, and while the compression ratio is nominally high, the small size of the cylinders and the non-aggressive valve timing result in a lower effective compression.

These engines truly run just fine on 87, and receive no benefits from a higher octane rating.

Wut he said ^

[pilotgeorge747]

Originally Posted by oreX

+1 to this.

I also think that three washers was killing the gas mileage.

I think I may go down to 2 washers as well. I have noticed my gas mileage did seem to be suffering a bit since adding the 3 washers. How much do you reckon it's changed since going down to 2 washers?

[saxnbass]

I gained maybe 5MPG on mine, not very significant in all honesty.

[pilotgeorge747]

Well since I was bored I just went out and removed the 3rd washer from the carbs. Didn't get a chance to ride it yet but so far it seems like it will need a bit of time to warm up before it is ridable without the choke. At least from my bread test start after removing the washers. I'm also considering replacing the snorkle as I way to quiet the bike a bit. I'll wait Until I can try the bike out with 2 washers before I experiment with that though.

[pilotgeorge747]

Just took the bike for a quick test ride and it does seem to be smoother although I'm not sure if I'd say pull harder though. Also the warm up didn't seem that much longer than with 3 washers. Basically just enough time to put your gloves on after starting it. Hopefully gas mileage improves a bit and then I'll be happy.

[cmSAE]

as the title says, i dont know anything about mechanical stuff. ive read some other threads about this, but i figured id just ask on one and see if i can figure my question out...

i have a 2012 stock (in engine mods) and im not sure whether or not this DIY is for me or not. like i said, i dont have an exhaust, still have my snorkel on, and no jet-kit (bc i dont even know what that is). I usually have to choke it for a min to warm it up, ive never stalled it, and i cant really tell if i have any dead areas on my high end rpms. im assuming that i dont need this, but if i get an exhaust system (looking at danmoto), will i need this?

[pilotgeorge747]

You don't need to do it even with the exhaust but once you get some experience with the bike you MAY want to try playing around with it to see if you can improve the smoothness of the powerband. The only benefits I can see from you doing the shimming now is to smooth out the lower end of the powerband (which helps for new riders) and possibly less warm up time with the choke.

[MikeBudd]

Originally Posted by cmSAE

as the title says, i dont know anything about mechanical stuff. ive read some other threads about this, but i figured id just ask on one and see if i can figure my question out...

i have a 2012 stock (in engine mods) and im not sure whether or not this DIY is for me or not. like i said, i dont have an exhaust, still have my snorkel on, and no jet-kit (bc i dont even know what that is). I usually have to choke it for a min to warm it up, ive never stalled it, and i cant really tell if i have any dead areas on my high end rpms. im assuming that i dont need this, but if i get an exhaust system (looking at danmoto), will i need this?

This thread should answer all of your questions:

http://www.ninjette.org/forums/showthread.php?t=9465

[cmSAE]

mike, i read that and like i said above, i figured it would just be easier to ask rather then decide if my bike is/isnt in need of this mod

[MikeBudd]

Originally Posted by cmSAE

mike, i read that and like i said above, i figured it would just be easier to ask rather then decide if my bike is/isnt in need of this mod

Fair enough. Technically you don't need to shim your bike.

I would try it if you have any troubles starting your bike from a stop (don't have to have stalled to have troubles).

Personally, I would give it a whirl just to learn a bit about your bike. It does take some time the first time you do it, but you do learn about the carbs and how to take off the fairings and gas tank. Things you definitely will need to know how to do if you ever want to do any work.

Add one or two washers. If it doesn't work out and makes things worse, change it back and your good to go.

Just make sure you have the right tools, and don't strip the carb top screws. Buy new hardware for the tops as well (m4x16mm cap socket screws [allen key] work well).

Cheers buddy.

[choneofakind]

Originally Posted by cmSAE

mike, i read that and like i said above, i figured it would just be easier to ask rather then decide if my bike is/isnt in need of this mod

For the record, Ride it. That will tell you what it needs in the way of carb changes.

If you're completely in stock form, you don't NEED to shim, it just helps a little because the needles are just a touch lean and make the bike surge a little. If you don't notice anything when riding, don't worry about making any changes.

[Mr.E]

Walked outside, saw my bike is leaking something, checked it out, Gas. Going to lowes to get me some screws now. Im pretty sure it's because I have improper screws in the carbs. This may be why my MPG went from 60 down to 30. :-\ I still think I may unshim, not sure yet though.