DIY Shimming the carb needles.

[Buffalony]

Originally Posted by kkim

It doesn't really matter. When you shim the needles, you are letting more fuel into the mixture at the carbs, so more will get sucked up at any comparable throttle setting from idle to about midrange. You might see a greater hit with an exhaust due to the freer flowing benefits of a full exhaust system, but the main mpg decrease would be from the needles in the carbs being higher.

K. Makes sense.
Might bump that MPG a tad more with a full exhaust then too eh.

[kkim]

yeah, it might if all things stayed the same. fact is, the bike becomes so much more run to ride, your throttle hand gets a bit enthusiastic at times.

[Buffalony]

Originally Posted by kkim

yeah, it might if all things stayed the same. fact is, the bike becomes so much more run to ride, your throttle hand gets a bit enthusiastic at times.

Before the pipe after the washies or after both?
I think the bike is fun as poop stock
I'll probably like it better after I install a 15t CSS.
eh guess it doesnt matter, I'll find out in about a month.

I plan on leaving the exhaust stock for this season. Figure I'd get some moneys worth out of it. Ya know? I'm just about done spending for this season also. I've already put WELL over a grand into her already . so far Im thinking shimming is a good cheap mod at 10cents a washer.

[kkim]

yes, best bang for the buck, which is why I'm such an advocate, in case you haven't noticed.

[B2FiNiTY]

What does the JIS head look like? I have a ton of bits but I'd like to make sure I don't have it before going out and purchasing one.

[Sound Wave]

Originally Posted by B2FiNiTY

What does the JIS head look like? I have a ton of bits but I'd like to make sure I don't have it before going out and purchasing one.

looking at it, it looks like an ordinary phillips screw bit. found this description on a website. it also includes pics:

10JIS - Japanese Industrial Standard
Often improperly referred to as Japanese Phillips. Commonly found in Japanese equipment. JIS looks much like a Phillips screw (and even more similar to Frearson), but is designed not to cam out and will, therefore, be damaged by a Phillips screwdriver if it is too tight. Heads are usually identifiable by a single raised dot to one side of the cross slot. JIS B 1012:1985 screw standard is throughout the Asia market and Japanese imports. The driver has a 57 degree point with a flat tip, parallel wings.

Advantages and Disadvantages of JIS

Most people and companies outside of Japan have absolutely no idea what they are. With the similarity in appearance to the Frearson and the Phillips the screws are often damaged in removing and installing with the wrong tools. JIS tends not to camout like Philips. The JIS driver can be used on Phillips quite easily but not reciprically. Drivers are not easily available in North America, try your local RC Airplane hobby shop. Most RC Helicopters use JIS screws to mount the propeller. JIS-spec cross-head screws are generally marked with a single raised dot or an "X". JIS always fit Phillip fasteners, but because of slight design differences, Phillips drivers may not fit JIS fasteners. (unless the tip is ground down a bit).

http://www.instructables.com/id/SAD3S3IFOVXPGXR/

here is where i got mine from: http://rjrcooltools.com/shop_item_de...m?subcat_ID=89

[kkim]

looks exactly like a phillips head, but the splines are cut at a different angle. you can identify which screws are JIS as they have a small dimple, which looks like a punch mark in them on the screw head next to the pattern.

http://www.ninjette.org/forums/showt...ghlight=screws

you can see the marks on the smaller screws holding on the float bowl in this picture.

[B2FiNiTY]

How can I tell if my screwdriver bit is a JIS or regular philips?

[kkim]

I would think it's written on the bit itself. do you have one in question? One wouldn't normally have JIS bits unless you specifically went out and purchased them.

[Jiu Jitsu Player]

I ordered a JIS screwdriver before I did this mod but it didn't come in on time. I was able to get the screws out with a regular #2 phillips. Like others have stated on here, the key is to apply a lot of downward pressure before you even start to turn the screwdriver. Mine came out no probs. I would suggest a screwdriver with a magnetic tip though. It definitely makes it easier getting the screws back in.

[Buffalony]

Some one correct me, I believe JIS parts have special thread sizes too. if your thinking about replacing these you might want to think again. Something else might seem like it fits but surely its not exact to the standard.

[Sound Wave]

you are right. they do come in different sizes. the one we would need for the carb needle covers is the #2.

[kkim]

Originally Posted by Buffalony

Some one correct me, I believe JIS parts have special thread sizes too. if your thinking about replacing these you might want to think again. Something else might seem like it fits but surely its not exact to the standard.

people have replaced these JIS screws with regular metric hex head bolts. they had no problems with threading.

[headshrink]

Too bad the service manual doesn't address the JIS issue....

[kkim]

what issue? They assume you are competent enough as a mechanic to work on the bike. I mean, they don't tell you what size wrench or what size phillips bit to use for other parts of the bike. Why would they tell you how to work on the carbs?

You need to remember this is the service manual... meant to be written to a service tech's level. They are not going to write this to a shade tree mechanic's level, which most of us are.

[headshrink]

That is a good point...
However, since they do list the "special tools" and virtually nobody in the US has heard of JIS, I would consider it a "specialty tool" in our market. Even a blurb in an apendex would be nice.

[kkim]

I guess they don't agree with you that the JIS screwdrivers are a "specialty tool".

[headshrink]

Originally Posted by kkim

I guess they don't agree with you that the JIS screwdrivers are a "specialty tool".

They clearly don't... I'm used to that though.

[Rocketman]

I had no problem with my philips driver....but ill pick one of these up regardless

[Ramen]

After weeks of being lazy, I gave it another go. I had to use my dremel to cut a flathead slot into the stripped screw, but I got it off!

The rest came off without at hitch - on one side. I dropped my JIS bit and it vanished into thin air. My garage floor must have a wormhole in it.

Not taking any chances, I used a needle-nosed vice grip to loosen up the rest of the screws on the left carb and then used a MOS and a #2 phillips bit to take them out. The left carb was a little harder because of the hoses that span over it. It wasn't until after I had the cover off that I got the bright idea to note and take them off. With my luck at this so far, I didn't want to go and put a hole in the diaphragm!

Using two brass #4 washers from Ace Hardware on each needle I could see the fit was just about perfect according to the posted pics in the thread. It was all downhill from there. While I had the fairing off, I removed the snorkel. Taking it out was more pulling than pushing for me.

BTW, check your coolant while you're at it. Mine was 1.5 inches below the low line. Thankfully I had half a bottle of 50/50 antifreeze and I filled it back to the full line.

I left the fairings off for the time being and put the seat back on. Starting it up, the sound from the bike had a lot more... gravitas. I'm very happy that I now will no longer sound like I'm dropping off Judy and the kids in the Jetsonmobile before heading to Spacely Sprockets. I took her down the road a bit and logged 3 miles. Taking off from a stop, I noticed that it was much easier and no longer have to curse at my bike for sputtering and hoping it doesn't stall in the middle of the intersection. Also, acceleration is much better for sure. I redlined her and hit 50 mph at the top of second gear. I better relearn how to short shift again before I get myself pulled over.

I felt like I have a whole new bike.

After I got back, I put the fairings back on and decided that this mod needed a real test or I'll never truly trust it. I decided to go for a little marathon and rode 60 miles - half of that on the interstate. The bike held up very well. On the highway, I went mostly around 85 mph. Passing was no problem whatsoever. No need to really drop a gear now! For a couple of minutes, I went WOT and got 99.5 mph indicated.


Needless to say, I'm a very happy boy. Thanks for all the help and I'll see you on the road.

[kkim]

[k4m1k4z3k]

So I just tried shimming with one #4 washer and pulled the snorkel. The bike ran great on a 3 mile trip to my girlfriend's house yesterday, but on the way back, the bike died at the stop sign leaving her court. I wasn't sure if i had accidentally hit the kill switch or what but the bike started back up and i was able to ride home without any problems. At home i checked the oil level while the engine was still hot and it was just at the high mark.

Now today, I went to start the bike and it was just barely able to maintain idle at 1000rpm and i tried to play with the choke - the bike dies as soon as the choke is engaged. I checked the oil level while the bike was still cold and it was way below the low line so I added a little oil until it showed in the sight glass and started the bike back up without the choke.

From there i was able to hop on highway for about 7miles followed by maybe another 5miles of lower speed riding on the main roads before i noticed that the engine peaks at 6500rpms in all but 6th gear. i can rev up to 6500 then the power just cuts until the revs drop below 6000 then it kicks back in again. Otherwise, the bike still feels/sounds OK.

So now I'm at school. the oil level looks like it may be fine (I'm not sure because I'm already 30min late and the bike is kinda on a slope). I'm 20miles from home and I'm just hopping I can make it back after classes.

So any ideas? Pinched diaphragm? Too lean (That results in white spark plugs right?)?
What should i check?

[Sound Wave]

kel, your symptoms sound a lot like jiu jitsu's. try reading earlier in this post. i think 1 or 2 pages back. are you sure that you put a #4 washer and not a 4 mm washer? was the washer pretty snug around the needle? it should be.

also, did you adjust the idle knob after shimming the needle? kinked hoses?

[k4m1k4z3k]

The idle speed didn't change much after shimming, but yes i did increase the idle a bit this morning. I can check the size of the washers again when i get home. Thanks! Its just strange that it wasn't a problem when i first did it - i'm pretty sure i ran through all the gears, but maybe now.

[k4m1k4z3k]

OK problem fixed. After class the bike wouldn't start up and i was forced to start taking it apart in the middle of the blazing hot parking lot. Looks like the vacuum hose under the tank was pinched. Made it home w/o any problems and the engine is revving normal like it was before.

Back to the point of this thread...talking about how great shimming is:
SHIMMING MAKES A WORLD OF DIFFERENCE IN THESE BIKES AND I LOVE IT! (minus the minor frustrations along the way)

[Viper-Byte]

Kel, really the point of this thread was to show people how to shim. But I will allow talking about how great a shimmed bike is over stock

Good to hear you like the changes, and yes, I too know all about the frustrations (stripped screw and washers too big)

[ahskeetz]

Hey All, i did this mod about a month ago but i have a question: how do you know if it's too rich or not? When i start my bike it starts great, but when i rev it up, it sounds like it is getting bogged down for just a sec then it revs up. Maybe its too rich? What do you guys think? i currently have 3 washers under it. It rides great, but maybe it might be too rich.

[kkim]

do you have the snorkel out? you can either take the snorkel out and see if that helps or take one washer out from each needle.

[Jiu Jitsu Player]

Originally Posted by k4m1k4z3k

So I just tried shimming with one #4 washer and pulled the snorkel. The bike ran great on a 3 mile trip to my girlfriend's house yesterday, but on the way back, the bike died at the stop sign leaving her court. I wasn't sure if i had accidentally hit the kill switch or what but the bike started back up and i was able to ride home without any problems. At home i checked the oil level while the engine was still hot and it was just at the high mark.

Now today, I went to start the bike and it was just barely able to maintain idle at 1000rpm and i tried to play with the choke - the bike dies as soon as the choke is engaged. I checked the oil level while the bike was still cold and it was way below the low line so I added a little oil until it showed in the sight glass and started the bike back up without the choke.

From there i was able to hop on highway for about 7miles followed by maybe another 5miles of lower speed riding on the main roads before i noticed that the engine peaks at 6500rpms in all but 6th gear. i can rev up to 6500 then the power just cuts until the revs drop below 6000 then it kicks back in again. Otherwise, the bike still feels/sounds OK.

So now I'm at school. the oil level looks like it may be fine (I'm not sure because I'm already 30min late and the bike is kinda on a slope). I'm 20miles from home and I'm just hopping I can make it back after classes.

So any ideas? Pinched diaphragm? Too lean (That results in white spark plugs right?)?
What should i check?

Kel- I had the exact same problem. The bike would initally start off fine and then run like a champ. Once I came to a full stop, it would sputter and die out. If you're still having problems I would bet that it's the size of the washers. Initially, the washers I used were too big for the white plastic part inside the spring to cover. I switched to a smaller size washer and I haven't had any problems since.

[Jiu Jitsu Player]

OAN: I've noticed a wierd sputterring problem sometimes when I'm taking off from a full stop. I shouldn't even say sputtering, more like gurgling. The bike takes off really slow then all of a sudden you can feel the torque kick in and it really starts to move. I'm not talking slow like normal accelleration type of slow. I mean slow like its almost starved for fuel for about 2 seconds then it finally kicks in. Any idea what could be causing this?

Currently I'm running 2 washers per needle with a snorkel pull. I got my 2 bros CF slip on in the mail today so I'll be installing it once I get home. I'll keep you guys posted if the problem persists with the new exhaust.

[Viper-Byte]

Chris, Kel has got his issue sorted out, it was a pinched hose.

It sounds like your idle circuit is too lean, I could be wrong, others with more knowledge will be able to advise.

[Jiu Jitsu Player]

Thanks Viper. I just read that now after I finished my washer shpiel. haha. Looks like my next mod needs to be some hooked on phonics tapes.

I'll check my idle setting but its usually at 1300-1400 once the bike is warmed up. Again this doesn't happen coming out of every full stop, maybe 1 out of every 5 but it happens enough for me to notice.I'll see how it goes with the new pipe.

[ahskeetz]

Originally Posted by kkim

do you have the snorkel out? you can either take the snorkel out and see if that helps or take one washer out from each needle.

Yeah, i have my snorkel out, but somehow I still feel like it isn't right... either too rich or too lean. Probably the former because my gas mileage is as low as 41mpg on highway.. I'll probably pull one of the washers off, gonna be a PITA to try and not strip the screws, also the little hoses that wrap around the carb cover are a PITA too because i can't manage to unhook them

[Jiu Jitsu Player]

Has anyone had any problems with the washers corroding on the needles? I was wondering since not everyone uses the same washer types if anyone experienced this. I used fiber washers- not too sure what the difference is and was wondering whether this would even be an issue.TIA

[Buffalony]

Good question Chris. I purchased Stainless incase this was a problem. Brass would probably be good. Dont know about vinyl. I think I asked Kelly this before and he said it shouldnt become a problem. But lets hear it from Kelly. Where is Kelly anyway?

[headshrink]

ooo.... I'm waiting to hear about washer corosion too....

Also, I have noticed my power band has felt very linear, there is no little boost toward the top end at all. Over all it is improved, so I am not asserting the power went away, maybe it was all raised.... anyways, I don't know if this is a good thing that we are all shooting for, or not, but I liked the feeling of a little boost at the top.

[Buffalony]

Originally Posted by headshrink

ooo.... I'm waiting to hear about washer corosion too....

LOL. Something along that line belongs in the "You might be a motorcyclist if" thread. funny funny

BTW: I have some extra 3mm stainless washies if anybody wants. PM me.

[TnNinjaGirl]

Originally Posted by Buffalony

BTW: I have some extra 3mm stainless washies if anybody wants. PM me.

Same here. I have a large stockpile and a good source. Let me know how many you want and where you live.

Except they are #4 washers, not 3mm.

[kkim]

I used some crappy 3mm zinc plated steel washers on mine that looked like they had rust forming when I installed them. I didn't have a problem with them when I had them in there. If you're concerned about corrosion when using steel washers, coat them lightly with grease to them when you install them. That should keep them from rusting. Stainless steel would be the way to go, but entirely overkill, IMO.

[B2FiNiTY]

i shall be attempting the task this weekend along with my first oil change and exhaust install.