question 4 carb gurus

[350xorbust]

On my 85 350x ,very suddenly, i was unable to start it. I kik and kik and no go. If i have the choke on...hot or cold...i get one fire and thats it. I have completely dissmantled the carb...blew it out and cleaned it well and found nothing amiss. If i bump start it it fires up imediately with no missung or hesitation.
After i have tried to kik it and then pull the plug...its dry. All filters are clean and the feul bowl is full but i cant get any feul to the cyl.as far as i can tell once it starts it runs fine....i just cant start it by kiking.....anyone?

[Flyingw]

The startup jet is plugged. That's the one that's pressed in. I'll get back to you in a bit.

[350xorbust]

Iv never heard of it called that coukf u show it to me with a pic so i know which one to clean? Thanx

[Flyingw]

This is the startup jet. You will need a #4 sheet metal screw. Turn the screw in about 1 full turn or more. Don't worry about damaging the jet. The metering hole is far below where the screw will reach. Now it has to be pried out. See the link. Page 1, post #3 on how to do it. This link is a tutorial on rebuilding the ES/SX and 350X carbs. They are all of the same series so you may use this to get your carb back in working order.

http://www.3wheelerworld.com/showthread.php/161746-ES-SX-350X-Carb-rebuild-Tutoral

[350xorbust]

Thanx fly...i will be gettin on that first thing tomorrow.....finally pointed in the right direction.....thank god too ...i aint 18 anymore...lol

[Flyingw]

Once you get the startup jet out, there is a nozzle down in the hole. Don't try to take it out. You will damage it. Shoot carb cleaner though all holes. Be sure to do the synchronization adjustment as outlined in the tutorial. Its important. Every hole in that carb should blow through to somewhere else except for the one next to the startup jet on the end. That one is not drilled through.

[350xorbust]

Well i read your tutorial end to end. I did the cold start fix, blew out the carb with both carb cleaner and air as well as chased as many holes as i could with mechanics wire...just to be %100 sure nothing is plugged and i can still kik till i colapse with exhaustion...and nothing. Bump start it hot or cold and away it goes...no problem. Im not wealthy but i am seriously thinking of a new carb. A replacment 400ex carb sells for $400 here in northern ontario....now u know why im so desperate for this to be resolved. Any other thoughts...

[Flyingw]

Send me your carb. I have a mockup I use to test the carbs I rebuild. I also have a bunch of 350X carb carcasses. I'll get to the bottom of it.

[DohcBikes]

Try turning the fuel mix screw out a half to a full turn and see if that helps. No offense but there are some assumptions going on here. For starters, just because the thread is titled as a carb issue, we have not even asked if or why he is sure of that. Weak spark can make it hard to kick start as well.

[350xorbust]

I thoughr about spark...but if i remove the tank and pour feul directly down the cylinder the engine will fire up with the throttle wide open,for a few secobds but will not continue. And yet a bump start in 2nd gear will fire it right up. I am steered more and more to that thought everytime i tear that darn carb apart.also if i try ti kik start it like i said before if there was no or poor spark the plug would be wet especially if i continued to use the choke but every time the plug comes out dry. Thats why i steered away from the weak spark theory. But i was wrong once back in the 80,s...lol

[350xorbust]

As far as sending the carb to you fly...im assuming your in the states...there goes another 2 to 3 weeks. No ofence to your abilities for sure but the darn border is hit and miss at best....usually miss..lol. if you have a rebuilt complete carb u want to sell me...please lmk

[350xorbust]

Uhhh i forgot to ask but is poor spark for start up a coil or stator issue? The reason i ask is because the coil has been in use for 27 years or so , but the engine and stator are new....nos take out crate engine. I know thats no garentee but personally i would point to coil. Yet whwn its hot it runs fine and i was always under the impression that that is when they fail???

[6speedthumper]

NOS 86 engine? In an 85? The regs are different, and I believe the cdi is different, although I could be wrong about that.

[DohcBikes]

I thoughr about spark...but if i remove the tank and pour feul directly down the cylinder the engine will fire up with the throttle wide open,for a few secobds but will not continue. And yet a bump start in 2nd gear will fire it right up. I am steered more and more to that thought everytime i tear that darn carb apart.also if i try ti kik start it like i said before if there was no or poor spark the plug would be wet especially if i continued to use the choke but every time the plug comes out dry. Thats why i steered away from the weak spark theory. But i was wrong once back in the 80,s...lol So have you tried adjusting the idle mix screw yet? I mean, it does sound like like the pilot circuit is not getting enough fuel just as the carb master says, but maybe you have the idle mix wrong. It has definitely happened to me before, once started the bike runs good, but is a bltch to kick start. Lean pilot size can also be the cause. How bout we fish around and try some tuning before pointing any certain direction....

[350xorbust]

Ya...iv tried it in every 1/4 turn incriment from a 1/4 turn out to 2 turns out. Idles best at 1 turn out....still cant start the damn thing....xuse the french
..

[350xorbust]

I did change the main jet to lean it out a bit as the plug was very black. I went to a smaller jet and then the plug looked good. I ran that jet for a week before i had the trouble with starting so i thought nothing of it. I went with a dynojet main jet and i kniw theire jet sizes dont match stock stuff but a buddy of mine crossed referenced the #s and gave me one a bit smaller. I can get the #s for ya but i wont be able to till tomorrow.

[350xorbust]

If i were interested in changing the coil out, does anyone know of a coil from a more modern quad that would work on my x? The reason i ask is the ease of obtaining one up here is always easier if its from a modern bike......would take some time to track an oem one down.....

[350xorbust]

Update: swapped out the coil from a proven 85 bigred and still nothing. Could it be a weak stator? If so should i swap it out for the spare stator and flywheel from my original 85 motor? Is that wven possible?

[Flyingw]

If you have a meter, you can put it on the black/red wire from the stator and take a resistance reading. That value will tell you the health of the exciter coil. Also, The 85 350X CDIs are known for the contacts that run from the plug to the circuit board breaking. Vibration causes this and it is very possible you have this going on in your CDI and kicking it isn't spinning the motor fast enough to get enough current to jump that broken connection as it does when its pull started. Not saying this is the cause but it is a possibility. I have seen electrical problems mask themselves as carb problems so I would put a meter on the exciter and pickup coils and se what the reading is to rule those out as suspects. If you have another CDI, try swapping it out. The factory manual tells you which wires to check for the two coils and what the value range should be.

[350xorbust]

I have already swapped out my other cdi and it didnt help. I will get that reading in ohms in a bit. Fyi the dynojet jet i have now is a 126. Aparently it equals a 135 oem. Stock that came in the kit was a 138. I have a cobra exhaust with a Yzf450r muffler welded on, a k&n filter and the "bolt in performance" cam from web cams. Otherwise the motor is stock.

[Flyingw]

Ok so strike the ignition coil and CDI off the list. Have you tried some fuel in the spark plug hole to see if it burps or anything?

[350xorbust]

Im still leaning towords a feul issue. When i swapped over the 85 bigred coil i kiked the engine over at least 20 plus times with the choke on full. (I know the choke works fine vecause it works when its running)the plug was dry. If all was working properly and i kiked it 20 times with the kill switch off the plug would be soaked.

[350xorbust]

Yes...dump feul down the cyl and it will fire up till the feul is gone...then nothing

[Flyingw]

Hmmmm, that takes me back to the carb and it not supplying fuel or enough fuel for startup.

[350xorbust]

Well all the ohms tests were done on the coil and stator and its components and all were found fine. So thats it....carb is gone. Time for a new one
So...if anyone has a 400ex carb to sell lmk.
BIG THANX to all that took the time to help. Couldnt of done it with out chas.

[DohcBikes]

The carb is not "gone". If you are dead set that is the issue, send that sucker to flyingw.

[350xorbust]

Iv spent all winter building this bike. Our summers up here are so short up here, that if I send my carb across the border, I wont be riding for way too long. I appreatiate the offer, but the new carb was just bought. $150 for a new Kiehien/ honda 400ex carb. If someone wants my carb, cover the cost of shipping and say $20, and its yours. I have spent the last 6 days in a row kiking my brains out...and Im done!!!

[oscarmayer]

do yourself a favor, do a compression test. if it's on the low side that too could pose an issue (enough to run once started but makes it tuff to get started). Another thing to try is a new plug. we had a bad new plug and once we figured it out, and swapped, no more issues.

not sure this could be your issue, but also check your valve adjustment. if too tight it could leave the valves hanging open and lowering compression during start up.

good luck and keep us posted.

[350xorbust]

Well the only part of that i didnt do was do a compression test although i cant see it being low as its a bear to start when the decomp lever is too loose....stops my 265lb advance dead in mid stroke...lol. tried several plugs incl a new one, and set the valves myself this time to the 4 thou that web cams recomended. I have had them as tight as 2 thou then the 3thou recomended by Honda. Iv also tried several different adjustments of the decompression lever and found it easier to kik with it adjusted at the tighter end of the spectrum.
Let me be clear. This isnt just hard to start....it doesnt even fire....well maybe once in a while but its like i turned off the kill switch.....dead!!.The new 400ex carb should be here in a week or so....and i will keep you guys abreast!

[DohcBikes]

I will keep you guys abreast!keep a couple if you have the room...

[350xorbust]

Two.....Big ones

[350xorbust]

Update: Well guys my 400ex carb (an actual Honda/ Keihien) not a chinese knock off, was in stalled today......Man....still cant kik it to start. Choke full on...fires once...choke half on...fires once...cant get it to fire at all with choke off at all. Holy crap I need a fix.
If you have been reading ( and I recomend going back and refreshing), about all iv done to get this beast to be able to start with the kikstart, then you r already aware that I have already tested the entire electrical system, and everything I can think of with the feul system, and I finally gave up and broke down and bought a new carb.
Any new insights would be extremely helpfull at this point
FYI...It ran perfectely once bump started with the old carb, but Im alone here for the next few days so I have no-one to pull me now that the new carb is in.
I pulled the bottom bowl off the 400 carb before I installed it today, and couldnt find any numbers on the jets, so other than saying its new and stock, I have no idea where it stands as far as jets are concerned....man how discouraging!!!!!...$150 spent for nothing...
The only thing I haven't done is a compression test...I will do one regardless but with it being an nos take out engine, I just cant see it being low on compression. It happened like this. I was out camping, and drove it for the whole weekend without issue, then loaded it up on my trailer and brought it home. At home I tried to kik it to unload it, and haven't been able to get it started since....low compression doesn't happen over night.....unless I maybe broke a ring....hhmmmm!!!. But even with the decompression lever adjusted to the tighter end of the aloud adj., it will still come up on compression in mid stroke, and stop my a*s dead. That to me is good not bad compression, but like I said I will track down a comp tester and give it a try!!!

[DohcBikes]

I took your advice and read this all again. I do see one guy that recommended more diagnosis before blaming the carb....

Something else I noticed, is that you said you changed the cam. This means somebody was in the motor, so you should stop refferring to it as an NOS motor, its not.

Ahem, this is not a joke guys....Did you break in the cam with oils containing high levels of zddp? A flat cam will do what you are describing as well. Just a thought.

Compression test, yes. Throttle open, choke off/open, kick till you see the highest number it will acheive. You already know this. Don't fake us out here, get us some real numbers. If they are high enough, then you move to a leak down test. If they are low, there are test to see why before you tear it down.

These two tests are about as easy as tying your shoes, will tell you more about your engine mechanically than any other tests, and I almost never see anybody on 3ww that convinces me they have actually done them. Just sayin.

[350xorbust]

I used an oil with 1400 parts per million...highest amount I could find...2000 rpm for 15 minutes just as Web cam recommended. As far as the term NOS is concerned, thats what it was. The only reason I said it ,was to easily explain that from the head down...it was nos.Everything but the cam.As far as the tests are concerned I will get on them asap. Dont have the gear so I will have to make a trip to the city.The only thing I dont know is the numbers. Whats acceptable for a comp test? and a leak down??

[350xorbust]

Well i did a compression test...will build my own leak down tester over the next few days...at first i only go 30psi...figured ya thetes my problem...loosened off the decomp cable and it went up to 85psi....i then remembered about the throttle needing to be open and it went back up to 140psi.....pretty healthy id say...but still cant start it my kikin!!!.
So we started replacing electrical components....started with the pickup...no change....went to a smaller cdi box....no change.(not sure which cdi box belongs to what year but they are dimensionally different). Still no change. The only component i havnt changed out is the stator itself. I have to go from an 86 setup to an 85 so i have to wait a bit so i can get a puller as the flywheels are a different diameter......
Will report in once iv gone further.

[DohcBikes]

140 max is not good for a fresh motor. Might be best to disconnect the decomp all together to get a good reading. If you pour a Lil oil in the plug hole and the number goes up... bad rings. Sorry I'm on the phone and can't see the screen

[350xorbust]

Update...well I finally came up with a flywheel puller, and swapped the flywheel, stator pickup and cdi from my new 86 stuff, to good 85 stuff, to see if the 86 stuff was week enough not to allow the engine to start with kik....NOPE....another $50 down the drain. Again...runs fine when bumped!!
Seeing as I had to build my own leak down tester....God I hate living here...I will finally have all the pieces needed by tomorrow , and will keep y,all up on WTF is wrong.!!!!!!!

[DohcBikes]

140 psi is not good for a fresh motor.

What happened to the leak down test? Too easy I fear.

Into the mic]"Is this thing on?"

[DohcBikes]

I did change the main jet to lean it out a bit as the plug was very black. I went to a smaller jet and then the plug looked good. I ran that jet for a week before i had the trouble with starting so i thought nothing of it. I went with a dynojet main jet and i kniw theire jet sizes dont match stock stuff but a buddy of mine crossed referenced the #s and gave me one a bit smaller. I can get the #s for ya but i wont be able to till tomorrow.Hmmmm. I'd be wanting more than 140psi and be doing a leak down. Failure after leaning, very interesting. Plug was black,,,, how do it run before you decided to lean it out? Hmmm. Interesting. I'd do some tests. Some easy ones.

[350xorbust]

Well before I had a chance to do my leakdown test, a buddy of mine tells me ...just for kiks, to remove the decompression lever all together and try....Holly s**t it fired right up. Iv kiked that thing over enough for 10 life times....well maybe not 10.... and it never dawned on me to do that. Fired right up ...one kik.
Screw it...electric start kit comin right up...just gotto find one. Now comes the task of finding that fine line between the electric start not being able to turn it over (I assume it wouldnt have enough power with no decomp) and having enough adjustment so it will.
Thanx guys for all your help...sorry it took so long