New carb installed but..

[Whisky]

It idles around 3000rpm I can take the idle screw completely out and still ides at 3000. The plunger is in correctly and there is plenty of slack in the cable. I put a 115 jet in on the advice of someone on here. No vacuum leaks that I can think off. Any ideas would be appreciated. I did a search already.:doh:

[cbrfxr67]

Choke on? You didn't say so gotta ask

[Chinabike]

Choke on? You didn't say so gotta ask

choke only to start, then off till bike idles.

You might want to try smaller main jets

[Whisky]

Choke on? You didn't say so gotta ask

nope I look inside end where air filter goes and slide will not go all the way down I don't see any obstructions anywhere

[Whisky]

what size 110--105?

[JerryHawk250]

Did you adjust the idle mixture screw?

[Whisky]

yes seated and out 1.5 turns

[cbrfxr67]

I'd open it up and make sure the cable is set right through the top. Maybe it's hung up somehow and not letting the slide go down. Keep fiddling with it, you'll get it.

[Whisky]

yes seated and out 1.5 turns

air fuel screw=seated and 1.5 turns out idle screw does nothing I can turn idle higher but not lower

[Whisky]

I'd open it up and make sure the cable is set right through the top. Maybe it's hung up somehow and not letting the slide go down. Keep fiddling with it, you'll get it.


cable is in correctly. I took cable completely off plunger and plunger still does not go down all the way. I do have carb off currently

[Whisky]

I changed to a 110 jet and idle is still 3k and when I give it some throttle it makes a sucking sound and dies.. going to put the 115 back in as it didn't have the throttle issue

[Whisky]

Probably will just put stock one back on for now

[JerryHawk250]

Do you have the slide in the right groove? You might have it reversed. The long narrow groove slides on the pin and the wide groove goes towards the idle screw.

[SilverBullet51]

Its going to idle high if the slide isn't going all the way down, it doesn't matter what jet you use if the slide doesn't seat. Is the needle sliding freely into the main jet?

[Whisky]

Its going to idle high if the slide isn't going all the way down, it doesn't matter what jet you use if the slide doesn't seat. Is the needle sliding freely into the main jet?

I had everything correct, as I said before I took the cable off the slide and the slide still doesn't go all the way down. It was an ebay Mikuni carb, could have been a lemon. I will spend more $ and get one straight from Mikuni this time. I put the stock one back on and it runs fine so that will have to due for now. Thanks for all the input though.

[Whisky]

One more thing before I buy a new carb, on the needle there is a clip at the top with several different places you can place the clip, would that have anything to do with the idle or the plunger not going all the way closed?

[Whisky]

I did notice the needle on the new carb is longer then the stock one, I'm thinking that might be keeping the slide from going all the way down. Does this sound like it could be the issue? Can I use the one from the stock carb? No that cant be right, it should be longer since the carb is bigger.

[RedCrowRides]

How far open is the slide being held? If it is not a lot then yes try moving the C clip on the needle, at this point it can't hurt and you can always put it back where it was. Moving it up on the needle should let the slide drop further closed iirc.

[JerryHawk250]

One more thing before I buy a new carb, on the needle there is a clip at the top with several different places you can place the clip, would that have anything to do with the idle or the plunger not going all the way closed?
Place the clip on the middle one. If it hesitates on throttling then drop it down one .

[Whisky]

here's a pic the idle screw on the right side is unscrewed so the other end is not holding up the slide. It came on the 2nd slot down from the top
http://i623.photobucket.com/albums/tt317/Whisky_82/20180920_213405.jpg the clip is on the middle one. It came on the 2nd slot down from the top

[SilverBullet51]

Ok the slide is supposed to be up a little like that, if it sealed completely you'd get no air into the cylinder. What size pilot jet are you running?

[Whisky]

I had a 115. Changed to 110 but back to the 115

[Whisky]

The stock carb had a 95

[Whisky]

When it was running at 3k. When I gave it some throttle it just bogged down.

[pete]

there dosn't seem to be any cut away on the slide..

are you sure it's the right way around..


.

[Whisky]

there dosn't seem to be any cut away on the slide..

are you sure it's the right way around..


.

Yeah it only fits in one way. left side inside has a small pin that sticks out and on the right side has the idle screw. Left side of slide has a small vertical grove cutout for the pin to slide in and on the right side has a bigger grove that goes maybe 1/4 of the way up from the bottom of the slide for the idle screw.

[Whisky]

My next day off I will try upping the jet size to 120 if no luck I will go down. I tried 110 and 115 with same results. Maybe mess a bit more with air/fuel screw. Maybe I have a vacuum leak somewhere. If all fails I will keep stock one on for awhile.

[JerryHawk250]

Could be a vacuum leak. I know this was asked already but what size pilot jet (slow speed) is installed?

[FLASHLIGHTBOY]

you know you tried a lot of stuff and keep having the problem.... the plunger has to go down as in the pic... and the needle has to go into the jet.. to seal it off... if it is too big for the jet.. or too high it sucks too much gas.... as I think you might know this... so where is the original jet that came with the carb... ??? the engine is getting too much gas ... does the needle fit into the carb idle jet??? and the cable is off... the idle screw is out all the way... then do this.. and see.. if the screw is not holding the plunger up.. and the thing starts up still and revs up... the idle plunger needle is too loose in the jet causing it to suck up too much gas,, move you c clip up all the way to the top... this will let the needle go into the idle jet more.. and cut off the excessive fuel.. you have to get the needle to cut back the fuel..

[Whisky]

Thank you, it has a 115 in it now but will try the 95 that it came with and move the clip to the top and go from there. Wont be able to try that until Sunday (Day off)

[Whisky]

you know you tried a lot of stuff and keep having the problem.... the plunger has to go down as in the pic... and the needle has to go into the jet.. to seal it off... if it is too big for the jet.. or too high it sucks too much gas.... as I think you might know this... so where is the original jet that came with the carb... ??? the engine is getting too much gas ... does the needle fit into the carb idle jet??? and the cable is off... the idle screw is out all the way... then do this.. and see.. if the screw is not holding the plunger up.. and the thing starts up still and revs up... the idle plunger needle is too loose in the jet causing it to suck up too much gas,, move you c clip up all the way to the top... this will let the needle go into the idle jet more.. and cut off the excessive fuel.. you have to get the needle to cut back the fuel..

Followed the advice from above and put the #95 jet that came with the carb and bike started right up, let it warm up, adjusted the idle and runs nice right at 1200rpm`s. I left the clip in the middle grove though. It might actually be running a little rich but want to ride it for a bit before I make anymore adjustments. Thanks a lot for your help from everyone. (My question now is, why do people put bigger jets in and run great and mine wouldn't run at all with a larger jet?)


http://i623.photobucket.com/albums/tt317/Whisky_82/20180923_161705.jpg

[RedCrowRides]

If the carb is a Mikuni clone, and particularly if your jet kit came from WingsMoto, there can be a significant amount of variation in the carbs as well as the jets.,and in quality in general.
I keep two complete WingsMoto jet kits around for that reason, i have seen the holes drilled off center, not completely drilled thru, ovaled out ,etc. So, my first guess would be you got ahold of mismatched or badly made carb /jets ,and the #95 was somewhere in the mix of variables that allowed it to function.



So, the good news is it's fixed ,the bad news is you might never know exactly what the issue was . But, I'd rather be ridin' and not know, than knowing and not riding lol. Peace !

[Whisky]

The 95 jet I used came with the carb. But running that size jet I probably ain't getting any more performance from the carb change? I'm half tempted to purchase a genuine Mikuni carb and jet kit.

[RedCrowRides]

If it is running well and not lean ,then you're likely getting all the performance gain there is to be had ,or so close to it that anything left to gain would be negligible .The VM22 is a better and larger carb ,and if you bought one that came in kit form with a new intake then that too is helping performance, it has a much bigger bore , like the carb does.


That said, parts aren't expensive so if you decide to experiment more then you aren't out a lot of cash but I really don't see you gaining a really noticeable gain ,again the key issue being is it running smooth now and not lean. Sea level range (altitude) ,relative humidity ,even temperature in general ( summer heat vs winter cold) can all affect jet sizing and performance .
The 95 that came with the carb, next time you have it apart , if that occasion arises, check that 95 's design against the jets you ordered and tried you had problems with .
There are a host of Mikuni clone carb makers out there and some use jets that are NOT made the same as other Mikuni jets ,it's possible all that jet trouble was because the aftermarket jets design isn't the same as the jet design in the carb itself, as in the design of the 95.,which would explain why none of them worked but going back to the 95 solved the issue .

[wlfpck]

(My question now is, why do people put bigger jets in and run great and mine wouldn't run at all with a larger jet?)


The reason for this is because people aren't sharing their location. Location is important due to altitude.

If you're at sea level, your jetting will be different versus when you're up a mountain.

[Whisky]

Gotcha. the carb came with the larger intake too. I will say it is running good. I will put a few miles on it then check the plug. I only have 70 miles on it so still breaking it in. I read it gets better with miles. Thanks again for the info.

[FLASHLIGHTBOY]

when some people change the carb to another carb and some jets... the needle size on the carb is different that the one that came with the new one.... too many mixing of parts... the needle on the new carb is sized for the new jet... I have seen where the needle was green or coated with a film... does not let needle seal the jet... hangs up and over fuels.. leave stuff alone sometimes.. of install new part ... it runs ok... then mod it.. and go from there...

[Whisky]

It is running a rich. Turn the air/fuel screw in a little?

[RedCrowRides]

Yes, but do it slowly. Try adjusting it in 1/4 turn increments ,a little can be a lot in with these small engines, and rich isn't nearly as potentially bad as too lean is. It shouldn't take too much if it is basically running okay now, you are just trying to fine tune.

[Whisky]

Turned a/f screw 1/4 turn in and took it for a ride, ran good for about 3.5 miles then started bogging and quit. Kind of lucky I was by a friends house so worked on it a bit there. Got it started and it ran for maybe 1 minute then quit again. Couldn't get it started so called another friend with a truck, got it started before he got there so he followed me and I made it about 2.5 miles and it quit. Loaded it up, got it home, got it going again but now I'm going to worry about when/where it will leave me stranded again. Not a fun evening and I'm afraid it will be the first of many.

[wlfpck]

Do a plug chop. There's a really good guide on chuckuslife on how to tune a carb.

Something weird is going on that is causing your bike to die. It seems like it's dying once you get to operating temp and have been running the bike for a while (based on what you've posted).

Is it dying at idle? Partial throttle? Where are you located/what is your altitude?

Humidity, altitude, etc. all play a part in the jetting of a carb.

A complete different solution is that they have EFI kits available on Aliexpress, eBay, etc. Not quite a direct solution for your problem.

[JerryHawk250]

Check the petcock and make sure the fuel is flowing freely. May be clogged or trash on the screen in the tank.

[RedCrowRides]

JerryHawk250 might be on to something here, it's not uncommon for the Chinese fuel lines to degrade quickly and begin to flake from the inside, which will clog and restrict fuel flow and delivery. You should always completely change all of the fuel lines out to some good silicone fuel line from any auto parts store, etc.
Also the petcock drill ,sounds like it's running too good for it to be a jet issue that would always be the same, but maybe it runs just long enough to float trash in the lines/petcock around til it settles somewhere that makes it start blocking fuel flow.


My last suggestion would be to check the valve settings ,if it's running good cold then runs long enough to get hot and quits the valve lash might be off, once warm/hot the gap is too tight and it quits. Also, make sure your spark plug cap is clean, and WELL seated, mine was halfassed on there from the factory and it started cutting out and acting crazy ,finally checked plug boot , pushed it on there all the way and instant fix.

[Whisky]

I will replace/check all you have mentioned. It was strange, I rode it around 20 miles before that but it was running rich, the plug was black and sooty, replaced it and turned a/f screw in 1/4 turn, that's when I went for my final ride of the day. I did buy a genuine Mikuni carb and jets to eliminate a china carb issue. It did start right up today but won't be riding until I get these things replaced. I'm located in Lincoln Nebraska, temperature has been 75-85. I will get it figured out. Again. Thanks for all your help.

[Whisky]

I purchased a genuine Mikuni carb and installed, started right up but had the high idle again, I tried everything. started w/100 jet, switched to a 95 then a 90, tried moving clip on needle to 2nd from top from factory middle, still idling at 4k, in fact it would still run with a/f turned all the way in. Took carb off and put stock one back on. It started but when it gets warmed up it dies. I can get it started with starting fluid but it wont stay running, when I do get it to idle around 1200-1400 as soon as I give it some throttle it boggs and dies. I think efi kit is in the near future as Im fed up trying to get bike running. I also noticed sometimes after it dies some gas comes out of the float overflow. Any other ideas?

[SilverBullet51]

Sounds like you might have some junk in the stock carb, and the fuel lines perhaps. And there are 2 jets on a carb a main jet ie. the #95 jet, and a pilot jet, (or idle jet) the genuine mikuni may have too big of a pilot jet, so the a/f screw can't compensate for the amount of fuel its flowing. Check that pilot jet size. The main jet should only affect 3/4 to full throttle.