DIY Shimming the carb needles.

[cbdallas]

The 4MM washers I used got hung up in the needle retainers, causing some REALLY bad running. Get them outa there.

I have noticed a dead spot in the very low rpm range when trying to pull slowly away from a stop. It's definitely a new condition since shimming the needles. Does drilling the slides cure this?

[Jeramir]

Originally Posted by cbdallas

The 4MM washers I used got hung up in the needle retainers, causing some REALLY bad running. Get them outa there.

I have noticed a dead spot in the very low rpm range when trying to pull slowly away from a stop. It's definitely a new condition since shimming the needles. Does drilling the slides cure this?

Ok i changed to the 3mm and its waaay better, but now i am having the same issue as you, when i try to pull from a stop i also get the same condition as you, like it hesitates to go away... any thoughts?

[ator]

Originally Posted by Jeramir

Ok i changed to the 3mm and its waaay better, but now i am having the same issue as you, when i try to pull from a stop i also get the same condition as you, like it hesitates to go away... any thoughts?

How many washers are you using? try taking one out on each side and see what happens

[choneofakind]

Originally Posted by massacremasses

If someone just sends me six I would be forever greatful

If you still don't have them by the first week of march, I'll send you some when I'm on spring break.

Originally Posted by cbdallas

I have noticed a dead spot in the very low rpm range when trying to pull slowly away from a stop. It's definitely a new condition since shimming the needles. Does drilling the slides cure this?

drilling only changes the throttle response, not the mixture.

Don't drill pregen slides. I had a bad experience with that in the 6k range.
The reason I had issues with that was at small throttle openings where the slides normally come up, they wouldn't, then they would snap open when I gave it gas. I plugged the holes. I'll try it again later when I can play around with needle height to compensate for the slide not rising.

That spot you're feeling is where the needles and pilot jets overlap. You can fiddle with your mix screws in very small increments and it gets better, but never goes away completely.

Originally Posted by Jeramir

Ok i changed to the 3mm and its waaay better, but now i am having the same issue as you, when i try to pull from a stop i also get the same condition as you, like it hesitates to go away... any thoughts?

Take them off. Add 1. test ride. add another. test ride. Add another. test ride. Stick with the number of washers that works best for you

They aren't going to be perfect because you're still on the stock needles. I think that area is where the taper of the needle comes into play. I'm personally just too cheap to pay for a jet kit to get rid of one tiny little spot that I'm only at for 0.001% of my riding.

[cbdallas]

Thanks a ton for the info. I may not even mess with it. It's a very minor & brief hesitation, and my needles are still capped :-(

[choneofakind]

Well next time you're in there for a valve adjustment or something big like that, take the carbs out and pull the EPA plugs. It's not too hard, just be easy with the drill so you don't try and drill through the mix screw

[cbdallas]

dammit2hell.....I just did a valve adjustment on 1/28. HA!

[choneofakind]

Oh well that's no good then hmmmmm what other maintenance could you do as an excuse to have other work to do so that pulling the carbs doesn't seem like such a big deal? is it time for a uni-trak linkage clean/lube job?

[cbdallas]

LOL. The bike just cleared 3,000 miles so I dunno if anything really needs to be done. I'll probably pull them someday for a cleaning and pop out the covers then. It runs really good right now other than that .5 second dead spot, and I know what's causing that, so I hate to fix what ain't broke. Occasionally, I make things worse when I start messing with things that don't need to be messed with. ;-)

[massacremasses]

yeah I could only find 4mm washers, glad I didnt get those... lol

[cbdallas]

Finally got sick of the low-end dead spot and removed the shims. SO worth it. Much easier to modulate the throttle, and the throttle off / throttle on transition is smooth again.

I guess this isn't such a great mod for the pre-gen....or it wasn't for mine, anyway.

[choneofakind]

How many did you have on? It works fantastically on mine. It's also the method for jetting that faq.ninja250.org suggests. It's a pretty common jetting trick.

[cbdallas]

I had no luck finding anything smaller than #4 stainless, (the ones that got stuck in the needle retainers) so I used a couple of rubber o-rings (I think they were off the mixture screws from my 94 250) I had left over from some carb work I did a few years ago. They fit snug at the tops of the needles. I think they may have been a hair thicker than the stainless washers. Only used one per side.

I noticed a dramatic difference this morning on the way to work with a slow take-off from the first stop light. I much rather sacrifice whatever midrange I may have gained with the washers for a much nicer low end without them.

[choneofakind]

OK, well SAE #4 washers are like half a mm thick. I'm betting that those o-rings were thicker. Likely 2 or 3 washers.

[massacremasses]

wait so is someone going to send me some or do I have to drive to Chico?

[choneofakind]

I won't be home for spring break till March 3rd or something. If you don't have them by then, I can send you some. You'd likely be better to just drive to Chico though

[massacremasses]

blehhh maybe Ill just try and see how it sounds without... but I was going to remove the snorkel too.. so maybe not.

[choneofakind]

http://www.ebay.com/itm/Tamiya-Washe...#ht_2089wt_905

http://faq.ninja250.org/wiki/Washers_for_carb_needles

[massacremasses]

theyll take to long to get here!!!

[Cab305]

This was a pretty easy DIY. I walked up to the counter and told the guy "hey, I want a jet kit installed and tuned on my 250" he said "no problem, come back in 2 days"

[choneofakind]

you're so impatient.

[massacremasses]

I bought them hopefully they will be here this weekend. If not oh well ill shim and de-snorkel later

[brendonjw]

Did mine the other weekend, but when i opened it up it already had 1 washer under 1 of the needles (the one on the left) Im the 1st owner so im guessing the workshop did it although why only one im not sure, i removed the snorkle and put 2 under each, but im thinking since there was one already under one needle should i have set it up as a 3 - 2 combo or a 2 - 1 combo maybe? Im at sea level with about 50% humidity most of the time, just giving it a run now and will check the plugs on my next tank of gas to see how its running

[kamikaze]

I found my washers at a hobby shop (r/c airplanes, helis, cars, etc) and I believe it cost me a whopping $1 for 10 pcs.

[Kingbeebe6373]

I think I may have stripped one of the screws on my carbs -.- Anyone know what I can do to get it out? Will I have to take it to a shop?
Sorry this is my first post (I think) but I have been watching and reading for quite a few months.
Any help is appreciated.
Thanks

[LoD575]

Originally Posted by Kingbeebe6373

I think I may have stripped one of the screws on my carbs -.- Anyone know what I can do to get it out? Will I have to take it to a shop?
Sorry this is my first post (I think) but I have been watching and reading for quite a few months.
Any help is appreciated.
Thanks

Depending on where the screw is at you might be able to get some needle nose vise grips on the head to turn the screw.

It worked for me to initially crack it loose then used a screwdriver to finish removing the screw.

[dubojr1]

Dremel is next. Have to grind a straight slot in it and remove it with a straight-head screwdriver. GL!

[Kingbeebe6373]

I initially had to do the needle nose on one, but its the center screw on the left carb and the frame, and plastic piece of the carb are in the way so i cant get a good angle with the needle nose. This also rules out the dremel in this case. Does it mean Im going to have to completely remove the carbs? ive look for a couple of guides but the few ive found have people who have pods, which is useless to me seeing as I still have my air box :\

[choneofakind]

The airbox really isn't as hard to work around as people make it out to be unless you're removing/installing the carbs all the time.

take off the carbs. Use a dremel to slot the head of the screw. (make sure to apply enough pressure with the flat head that you don't strip that too) Then replace all the screws with M4x16 hex screws and you'll never have this problem again.

[Kevin2109]

Originally Posted by choneofakind

The airbox really isn't as hard to work around as people make it out to be unless you're removing/installing the carbs all the time.

Dude, have you pulled yours before? Its a PITA with the airbox

Do yourself a favor and get the pods, I even have jets for ya

[choneofakind]

Yes I have. The carbs have been out quite a few times, and the airbox has been taking apart and removed to have the battery box cut off of it to make carb removal easier so that I don't have to loosen the fender every time.

Plus I opened the intake lid and have 108 jets (instead of 105) that I'm going to test out. I'm toying with the R-0990, but idk how badly that's going to affect my mileage. Plus I just did the intake lid mod, so I wanna get that right and have some fun tuning that before I just go make more changes.


*edit*
I'm considering doing pods. It's only $38 on amazon including the breather. Free Prime shipping.

Originally Posted by Kevin2109

I even have jets for ya

You have a pair of 110's and 112's you'd be willing to part with for free? (pretty please?? )

Damn you Kevin.
*/edit*

[ator]

Well, I shimmed my needles today. Put 2 washers on each needle. Bike started up with no choke. Had to use the choke to warm it for a minute, then started to ride it and took the choke off. Ran noticeably better, then I realized that its only 40 out. So I decided to wait till its warmer, I'll ride it again, go from there.

Took me a total of 2 hours, and that includes installing the steering damper as well. I had no trouble getting the screws off the carb covers. Right tool for the right job. I went ahead and put the same screws back on since I didn't have any trouble getting them off and I didn't damage them.

[choneofakind]

Originally Posted by ator

Put 2 washers on each needle.

Originally Posted by ator

Bike started up with no choke.

these two things really have no connection, but I'm really glad you're enjoying the raised needles.

[ator]

Well, in this cold weather, the bike wouldn't start without choke prior to the needle shimming. If it's a coincidence then so be it.

**Edit

Chris, I just noticed you have this bike listed under bikes



I have about 20 bicycles, you can see some of them here: http://bmxmuseum.com/user/26916

[EthioKnight]

Ok...there have been repeated mentions of using the "right tool" to unscrew the screws on the carbs. I am getting ready to shim mine (as soon as I get my DanMoto) and I have the usual assortment of screw drivers (craftsman, and others), is there such a thing as the 'perfect' driver/tool for the job? so that I can get to buying it...tnx!

[choneofakind]

They're Japanese Industry Standard heads on the screws. That means you need a JIS bit if you want the "right" tool.

Personally, I just got annoyed at them and just replaced all the screws on the bowls and caps.

[ator]

Here's what I used, worked perfectly

http://www.harborfreight.com/8-piece...ver-92630.html

[EthioKnight]

Thanks guys. Chris, I'd rather not do any retrofitting now, maybe later, when I feel more confident about working on the carbs. Chris (sh!t...there's two of you!) tnx, I'll pick that set up tomorrow.

[MikeBudd]

Originally Posted by EthioKnight

Thanks guys. Chris, I'd rather not do any retrofitting now, maybe later, when I feel more confident about working on the carbs. Chris (sh!t...there's two of you!) tnx, I'll pick that set up tomorrow.

Just buy drywall screw bits and put them in the angle driver (if they aren't all ready). They grip the screws MUCH better, and that makes sure that you don't strip them.

I'm not exactly sure what you mean by retro-fitting, but installing new screws is DEFINITELY the way to go even the first time you shim your needles. Getting those screws stripped is SUPER easy. I mean if you find it easy, keep those suckers in, but man, I wanted to kill them for putting those babies on there.

I had to replace mine because 2 out of the 8 screws broke in half the third time I took the carbie covers off. I'm actually left with half of in in the very bottom of one of the holes and I can't get it out (I'm going to have to drill it...). I didn't wan't to risk it happening again.

Cheers

[choneofakind]

Originally Posted by ator

**Edit

Chris, I just noticed you have this bike listed under bikes



I have about 20 bicycles, you can see some of them here: http://bmxmuseum.com/user/26916

I like the all white one. I suck on bmx bikes I can rock wheelies and endos (but only on bikes with a solid fork) and bunny hops, but that's about it.

yeah buddy that's my ride on the trails and around campus. Best bang for your buck on a full suspension bike. I wish it had a full floating suspension like the Trek Remedy and a better fork, but hey. I had a budget, and I love the bike.