Plug Fouling

[PHAT400]

Alright, I changed the pilot jet to accomadate cold weather starting. That's better , but the dang thing is still fouling the plug. I do get a few more cold start's from it, but it still is'nt right.

Also, with that said, what problems could I expect when i remove the choke?



:grr:

[Aceman]

Is it idling when you foul the plug or are you running it around and it fouls the plug? What size is the PJ you have in it now? Did you leave the choke partly on?

[PHAT400]

Originally posted by Aceman
Is it idling when you foul the plug or are you running it around and it fouls the plug? What size is the PJ you have in it now? Did you leave the choke partly on?

OK, I'll go to start it after sitting for a weak, it's cold (30 f) after about 2-3 weeks of this (being started and ridden at least 4-5 times) it will not start. Take out the plug and all wet and fouled. I only use the choke (half) to start it. Then off.

PJ is 42.

[cals400ex]

what size pilot jet you using?? how many turns out on the fuel skrew are you?

[PHAT400]

Pilot jet is a 42. Fuel screw? Where is that located? Right in front of the choke lever? If that's the one, is'nt that also called the idle screw? Sorry, rookie...

[cals400ex]

no, the idle skrew is by the choke lever. the idle skrew is silver. the fuel skrew is on the very bottom of the carb. it is a bronze colored skrew. you use a small flat blade skrewdriver to adjust it. it is hard to see when the carb is still on the bike if you don't know where it is located.

when starting the bike, this is what i do. put it on full choke. pump the throttle 4 or 5 times. hit the start button without hitting the gas. usually starts every time unless i have that darn aftermarket ignition box on. by the way, i use a 42 pilot jet too. my fuel skrew is set at 2 turns out from lightly seated.

[PHAT400]

SWEET:D I'll try it tonight....

:macho

[cals400ex]

just remember, 2 turns out might not be what you need. i don't know what temp it is there or what elevation your at. also, i don't know your mods or if you are running an airbox lid or not. i would probally suggest to turn yours out 2.5 turns to be on the safe side. its always better to be a tad rich than lean so the bike stays cooler.

[PHAT400]

Originally posted by cals400ex
just remember, 2 turns out might not be what you need. i don't know what temp it is there or what elevation your at. also, i don't know your mods or if you are running an airbox lid or not. i would probally suggest to turn yours out 2.5 turns to be on the safe side. its always better to be a tad rich than lean so the bike stays cooler.

795' asl it's 27 f right now. no mod's except sparks timing key.

[cals400ex]

thats pretty similar as my elevation and temp. i just realized after reading the temps and elevation of your location that your not too far from me. i would go at least 2 turns out on the fuel skrew to start with. if you notice that you bike wants to pop a little bit on deceleration, just start turning the fuel skrew out a little bit at a time. good luck

[PHAT400]

To start should I set the screw all the way in and then back it out 2 turn's...

[hondafox440]

Yes, but don't tighten it down with 5000 ft/bs of torque. What I do is hold the screwdriver by the actual metal shaft (not the handle) and tighten it until it stops, then turn it a little bit more using the handle. This is called lightly seated. Then back it out 2 full turns. Remember to do 2 full rotations out, I have done 2 half turn plenty of times by mistake and thought it was 2 full ones.

[PHAT400]

Cool, thanks! ;)

[LazeR]

How exactly do you adjust the fuel screw without taking off the carb? I haven't found any screw driver to fit in there!

[hondafox440]

I haven't done it, but I know on most carbs you can loosen the clamps on both ends and rotate the carb. Turn the bars to the left to give youself some more slack in the throttle cable.

[PHAT400]

Taking it off's seem's easy enough. Done it 3 or 4 times so far...
(me... dumb *** rookie :rolleyes: )

[PHAT400]

OK, back at it again.. Have done all of above, dang thing is still hard to start in cold and foul's the plug.

Should I check the needle, the main jet or what.

So far only mod's are SPARKS timing key, 42 pilot jet and no air box lid. Right now it is 25 degree's f and have not ridden in 1 week. Fuel screw is out 2.5-3 turn's...

WTF?

DENO



:macho

[cals400ex]

Originally posted by PHAT400
OK, back at it again.. Have done all of above, dang thing is still hard to start in cold and foul's the plug.

Should I check the needle, the main jet or what.

So far only mod's are SPARKS timing key, 42 pilot jet and no air box lid. Right now it is 25 degree's f and have not ridden in 1 week. Fuel screw is out 2.5-3 turn's...

WTF?

DENO



:macho


are you sure your out 2.5 to 3 full turns on the fuel skrew?? just wondering because some people turn it a half of a revolution instead of one? if thats all good, make sure you pump the gas 5 or 6 times before hitting the start button. after pumping the gas, hit the start button without giving it any fuel. there is a good chance it will fire up. if not, i put the choke on and it doesn't have any problem firing up. i would put in a new plug too. i have had a bad plug once since i started riding.

[xc400ex]

This may sound really stupid but once you think about it you'll realize this is the stock 400's starting problem. Mine fouled 15 plugs in the first month i had it i bought it brand new. Air filter came off on a moto x track and i had to rebuild it. Put a JE 416 piston in it left the cam stock. The bike wouldnt run and didnt have any compression after i rebuilt it. I pressed the decompression assembly off the stock cam put it back together and it ran great. Now ive had the same plug in it since August and i ride nearly ever day. I think the stock decomp mechanism fails and the motor just turns over wont start cause of no compression and all the fuel fouls the plug. Now my jetting can be rich lean anything the plug is impossible to foul.

[PHAT400]

CRAP! I was hoping that something like that would never come up...
Thank's for the hint's...

Deno
:macho