question 4 carb gurus

[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