Weird issue, don't think its jetting. Bike won't start unless throttle

[ShelbyVoodoo]

I picked up an 04 Shee for a good deal recently and seem to have an odd issue with the bike.  I run a mix of race fuel in all of my bikes,  I have a 97 RM250 and a 95KX250 that I rebuilt completely (motors and all) that run perfectly.  I had them dialed in with PWK carbs but went with Lectrons.  Just an FYI on my experience with jetting etc.   I mix VP113 with 91 at a ratio where I get about 94 octane and go a littler higher at 101 with my KX250 because it has higher compression.  

So, ill get to the Shee.  From what I can tell the motor is stock.  It has FMF headers, silencers, pods, airbox delete and some slight frame shave mods for lightening.  I guess it was going to be a drag shee.  I looked it over like mad when I got it.  The bike just had a new top end installed with Wiseco pistons (have receipts).   The bike has a Dynatek non programmable CDI from what I can find.  TORS deleted.  Aftermarket killswitch which works perfectly.  No key, no lights, no ebrake.  

The bike is hard to start when it is cold.  I checked the jets and it has 25P and 230M in both.  I removed both carbs and cleaned them, cleaned the jets, blew through jets etc.  But the bike will not start.  It starts and then dies and starts and dies.  I have gone from 3/4 turn out on the air screws in quarter increments to 3 turns out trying to get it to start.  I screwed the idle screws all the way in, and same increments out.   

I can kick the bike until I am blue in the face but it will not start.  However, if I give it a tiny tiny bit of throttle while kicking it roars to life and when I have the idle screws maxed in it revs as it should with the idle turned all the way up.  I can back the idle off and it stays on and runs perfectly.  Once the bike is hot it starts in one easy kick.  But when it sits it does the same thing.  Won't start, but a little throttle and boom, ready to go.  

I know that this is not right.  I plan on going up a size in jetting to 27.5P because I am high altitude and its getting pretty cold here.  I ride year around.  I can handle the jetting.  I have the needles set at 4th clip from the bottom which got rid of a god awful bog that it had.  The Dynatek CDI doesnt seem to change anything at all when the clips are changed.  

Could this just be the reeds going bad?  I checked for leaks and sprayed starter fluid all around the bike when it was on and it had no leaks.   Compression is solid because once its on it runs fine unless the idle is too low.  I do notice that when the bike gets kicked and kicked it does smoke a bit, but I use Castor 927 and my bikes even smoke until they warm up.  One the shee is warmed up it doesnt smoke much.  Its extremely fast and easily pulls the fronts up with the stock suspension and swing arm.  

Should I just can the Dynatek CDI and put a stocker on it with a timing plate?  I dont really like electronics on my two strokes.  Both of my bikes run like beasts.   I am having an issue with the clutch dragging AFTER it warms up as well.  I am going to completely replace the shift fork, star, clutch basket etc soon.  I plan on doing a super cub build pretty quickly.  

[375hp banshees]

Why dont you just leave the idle where it starts?

Youre probably to lean on the pilot

Or the pilot circuit is plugged & your running off the needle,

Choke tubes on, slides are in correctly?

 

[ShelbyVoodoo]

It wont start without the throttle at all.  I am going to order a new choke tube.  It is in correctly but falls in easily so that may be it.  I took the carbs off and cleaned them thoroughly including each jet individually.   When I give it a little throttle and it starts with the idle turned up, it idles higher than its supposed to to stay on.  I should have the 27.5 pilots in pretty soon.  I will toss those in.   I did notice one thing on the carbs, it seems like the idle screw on the left carb, the one with the choke, may have been installed a little off.  You can't twist it in very far before it bottoms out.  Meaning that when I sync the carbs and move the idle screws until they touch the slides, you can screw the right idle adjustment in like 3.5 turns before it is all the way up.  The left one you can only screw in like 1.75 times before its all the way up.  

[375hp banshees]

You can adjust it by the cable to but, if it's too high, it's too high.
How does it do with the air screw all the way in?

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[375hp banshees]

The bowls are side specific also

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[ShelbyVoodoo]

When the air screw is all the way in, it does the same thing when I try and start it.  I kick it and it starts like it wants to but immediately dies.  It doesnt bog out.  It growls a little, like they usually do before they come to life, but instead of starting and idling it just dies off.  I made sure the bowls were on the right carb.  I went through this site and others for several hours looking for answers.  I finally posted.  I am going to go by Yamaha later and see if I can get some reeds.  I think the dealer here stocks accessories at the shop.  When I get the 27.5 jets I will install them and see if that works.  If not, I will probably order a stock CDI.  I literally cannot tell any difference with the Dynatek installed.  The bike feels the same on all maps. 

Before I moved the needle up a notch there was a bog and then the power came on like a light switch.  I moved the needle and now there is only a tiny bit of hesitation before the power slams on and the front wheels lift up.  I know its not the fuel because both of my bikes run very well on the same mixture.   My RM250 has a bit of pipe bang when using 91.  With my mix its very smooth, even for a two stroke.  Its also very fast.  Same with the KX250.  Both of them start very easily.  When they are cold it takes a couple of priming kicks and then they start no issue at all with the Lectrons.  I also checked the spark and put new plugs in it with .30 gap on both sides.  NGK OEM plugs. 

I am ordering a new choke tube, carb rebuilds etc from Vitos, unless I can find a better deal local or online somewhere.

[375hp banshees]

Better deal isnt better. DONOT buy from vitos... most stick with stock cdi.

 

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[ShelbyVoodoo]

I have no idea if its ported.  I am thinking that it was.  I have 30 pilots that I tried but it was definitely too rich.  So I went outside and cranked the idle all the way up.  The air screws were at 3/4th turn.  Even with the choke it would not start.  I am pretty sure the choke is toast.  It is a Vitos choke.  I can see that now because I took it out.  I will get an OEM choke.  I left the idle cranked up all the way and turned the air screws all the way in and kicked it and it wouldnt start.  So I backed the screws out 1/8th of a turn.  The engine was loaded up with fuel from me kicking it so the first kick had some heavy compression so I just slowly kicked it until it felt normal and then gave it a nice kick and it started and stayed on.  The idle was a little high so I backed it off a half turn and it died.  So I set the idle at a quarter out and kicked it and it stayed on and idled fine.  

So that tells me that the 27.5's will most likely fix it.  Odd that it even tries to start though.  My bikes won't even chug if they are too lean.   I have a lot of stuff that I want to order.  Who should I buy from?  I am going by Yamaha today to see if I can get some new reeds.  When I get a new bike I replace all wear items and if I pull something off that is still good I keep it as a spare.  I am shopping for the below.  Pretty much redoing the entire bike.  I picked up a new front master cylinder/perch/lever because the morons who had the bike stripped the screws on the perch so badly that it couldnt even be tapped to the next size.  I replaced the clutch cable and the throttle cables.   Do we get any discount from anyone?  I want to see if I can get a package deal since I am ordering a ton at once. 

Billet Clutch Basket

Clutch Fibers

Push Rod with ceramic ball

Super Cub Kit

Wheels

Tires

Full Suspension

A Arms

-2 Swingarm.  

Chain

Sprockets

Rotors

Hubs

Radiator Mounts

Grommets

Exhaust coupler

Maybe new carbs instead of a rebuild kit, especially if I am going super cub.  Possibly Lectron

[375hp banshees]

Depends.. f.a.s t.

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[hoppedupandcutdown]

Check that the air pilot jet is indeed a 1.6, it's located on the air filter side in the horn. A pilot jet (25up) will screw in, but are too huge to work .

[ShelbyVoodoo]

So I received the 27.5 pilot jets.  I installed them and again I cleaned the carbs thoroughly.  Both carbs, as well as measured the float bowl height with digital calipers.  They are set at 21mm.  The bike starts, but again only with a little throttle.  I think my choke tube is toast so I ordered a new one.  Once the bike is started with the throttle, as long as I have the idle up high enough, the bike will stay on.  But if I don't have the idle set higher than normal, the bike will die.  I believe the timing is set at either +4 or +6 degrees.  I can't really tell what maps are on the dynatek ignition and I don't have the programmer for it.  I had to reset the air screws yesterday because of the bigger jets.  They are out 1.25 turns and the bike runs well with that.  The only issue is starting the bike initially.  I have to give it a little throttle or it just burbles and dies.  

[fastbanshee8]

Hard starting when it's cold is a sign that it's lean.  Replace the choke tube, and if that doesn't help, then go to 30 pilot jets.

[375hp banshees]

Couple things, un relayed, but just fyi. Make sure, it in fact has stock timing plate, alot advance with dyna & boom. The idle screws can be made longer( stop from bottoming out) by shaving the newly threaded boss, that was tapped for tors delete.

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[ShelbyVoodoo]

5 hours ago, 375hp banshees said:

Couple things, un relayed, but just fyi. Make sure, it in fact has stock timing plate, alot advance with dyna & boom. The idle screws can be made longer( stop from bottoming out) by shaving the newly threaded boss, that was tapped for tors delete.

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How do you do this?  I think this would help.  The bike has the stock timing plate from what I can see.  I don't know what curves are set on the Dyna.  It feels different on different maps but not that different.  I set the Dyna to the "stock" setting, but it feels like the timing is still advanced.  It runs well when the idle is up.  I also tried the 30 jets and it was bog city.  I couldnt get it to even start with the idle all the way in.  I tried the air screws with the 30 pilots in every 8th turn setting from .5 turns out all the way until they almost came out of the carbs.  I know the choke is dead for sure because it does nothing unless I hold it all the way out by hand.  I ordered carb rebuild kits as well because it seems that now the float is getting stuck open on the 1-1 carb.  I can tap the bowl and get it to work but every few times I try and start the bike it starts pouring fuel out.  Thats a nice waste of T2 fuel.  

When I turn the idle in a half turn from where I have it set to ride, the bike will start and will idle and stay on, but only after I start it the first time with a little throttle.  Then I can shut it off, even if not warm all the way and kick it once and it will stay on.  But when the bike warms up the idle goes up and I have to back it down a quarter or half turn.  

[375hp banshees]

File or dremmel. most do it before they tap it. all you have to do is make sure the 1st thread is OK when done, and that its flat, so the jam nut seats good and won't un-thread.
Are you using a vacuum tester to sync @ idle. I wonder if you're not synced?
Did you look at the jet size that hoppedup mentioned?

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