Another Question - Can't find an answer anywhere.

[rYan01400EX]

Alright - I've done it all....

This is stumping me like crazy.

My 400EX runs like.... CRAP. It doesn't even want to run. I've done absolutely EVERYTHING I can think of. Adjusted valves, went through 6 or 7 million jets (give or take a few.) My plug looks maybe like its fuel fouled. Dad, thinks it's oil fouled. I don't know what to do.. I've turned the fuel screw so many times its probably about to curl over and die. I have done EVERYTHING. I don't know what to do.. or anything close to what the problem is... I do know it sounds like it's flooding itself out one way or the other. In the chart under the "Articles" section on the homepage would be identical too the "Wet Fouling" picture..


If anyone can help or atleast point me in a direction it would be GREATLY appreciated as noone can give me the answer.

Ryan

[Eviltanker]

Wet fouling as you know is oil on the plug. Put your Jetting back to factory(38, 148) Set your fuel screw back to factory (2 1/4) and give her a shot. What other mods you got? did you check your spark arrester? Could also be rings.

[zrpilot]

Try a new plug.

[rYan01400EX]

I've put a new plug in it.. I don't have a spark arrester... and the piston/rings just installed 2 or so months ago.


See, this is why I am stuck.. Hahaha.

[Eviltanker]

Out of the manual, you could also look at these things:
Clogged fuel line or fuel valve
FUEL SYSTEM
choke operation incorrect
clogged airfilter
low idle speed
clogged/pinched fueltank vent hose
misadjusted pilot screw
carburetor float valve sticking
clogged jets
loose carb mounting bolts
air leaks at intake manifold
clogged muffler
a couple from the engine part:
Incorrect valve clearence
loose cylinder head bolts
leaking cylinder head gasket
stuck/seized valve
incorrect valve timing
Excessive oil level in crank case
malfuntioning valve decompressor
that is a few things that will affect your starting/idling/power and performance

[rYan01400EX]

Thanks Evil.. I've narrowed it down to the possibilities but still have a few questions.


I've narrowed it to these things -

1. Misadjusted Pilot Screw - how can you misadjust this? I thought you just put it in 'til tight.

2. Carbureator Float Valve Sticking - I don't think this is or else gas would pour from the vent hose correct? If it does, whats the fix to this? Tap the bowl?

3.Possibly and air leak.

4. Valve Clearance - this could be an issue. I adjust them while at TDC - BUT - If I do all of them then I have to back the screws out so far that they hit the caps when running. Whats the deal here?

5. Head Gasket - could also be a problem.

6. Timing - May be 180 degrees out or off a tooth or something.. Will retime.

7. Oil Level - Could also be a possibility too.. But - oil only comes up about half way between "Add" and "Full."

8. The Decompression Mechanism - What happens if you spin the crank the wrong way. My father spun it clockwise because he couldn't remember how to do it... How do you fix this? This could be the problem actually.

I know, I ask stupid questions. So, flame on. But I'm just looking for the correct answer before I decide to just tear my motor part without knowing what to look for... So thanks to all of you who have answered!

[rYan01400EX]

Up?

[JOEX]

Post a COMPLETE list of mods, repairs, replacement parts and current set up.

[rYan01400EX]

Ah man - here we go...

Big Gun Exhaust
42 Pilot - 155 Main - Dynojet Needle (Clip in 3rd Slot)
New Air Box
K&N Filter
Wiseco 10.8:1 406CC Piston
Oil Filter and Things
Barnett Dirt Digger Clutch
Stock Cam
2 New Valves - bent two due to melting stock piston on intake side.
Replacement sprockets - same size.
Stock CDI
Airbox lid is on but drilled.


I think thats all - motor wise.

[JOEX]

Originally posted by rYan01400EX
Ah man - here we go...

Big Gun Exhaust
42 Pilot - 155 Main - Dynojet Needle (Clip in 3rd Slot)
New Air Box
K&N Filter
Wiseco 10.8:1 406CC Piston
Oil Filter and Things
Barnett Dirt Digger Clutch
Stock Cam
2 New Valves - bent two due to melting stock piston on intake side.
Replacement sprockets - same size.
Stock CDI
Airbox lid is on but drilled.


I think thats all - motor wise.
Assuming you're using a DJ main jet i'd say you're a bit rich...

[rYan01400EX]

You're exactly right.. are they a bit richer then an original keihin jet.

[Eviltanker]

You have an after market exhaust and air filter you might want to try 2 1/2 out from lightly seated on the pilot screw.

[Eviltanker]

when you do the valves when you hit TDC on the notch try to move the arms over the valve springs. If they move you are on the wrong stroke. go one more revolution and check them again. I believe thats how it is.

[ckasper18]

Try a new needle and seat is it fouling plugs at a idle i personally do not like the K&n jet kits

[Eviltanker]

Go to Jetsrus and order yourself Keihin Jets. They are good priced and quick shipping. Order yourself 150 through 160mains and a40 and 42. Everybody has a preference on jets, I prefer Keihin jets beings I like to have the jets that are made for the carb. It is entirely up to you though.

[Kaleigh]

has this just happened or has it been happening since the piston was installed.. if it has been happening since.. could be your ring position.. just a guess.. if not then it really sounds like you're rich..