Hard Starting?

[tim-4par]

I need help. Bike has always been difficult to start when cold. It's gotten worse. I can only start it by bump starting. After it's warm, no problems. Battery is good. Holds a charge. Think my valves might be tight? Any help would be nice. Thanks.

[mojoe2878]

check the valve adjustments.
if you have an aftermarket rev box on there then it will make it hard to start when its cold.

[6arett]

what bike you got?

[tim-4par]

OK. Here it is. I've got an '01 400EX. White Bros. rev box. DMC exhaust. Hotcam stage one. Wiseco 12:1 piston. 426 kit. Runs fine.. when I can get it started. It'll run fine, after I pull start it and get it warm. I checked the valve clearances today. They're fine. Now I need to check the spark. See if it's getting enough juice. Any help?! Thanks.

[bradley300]

its your rev box, ditch that piece of crap for a rev box made for your quad (the white brothers/big gun rev box is just a stock xr250 box) gthunder and i think curtis sparks both make correct rev boxxes for the 400ex. www.gthunder.com

[Toadz400]

I'm surprised no one has mentioned jetting. Sounds like your jetting is off, has the temperature changed lately? Like...extremely colder?

[hondarider2006]

Trying going with the 42 pilot. Doesn't sound like your problem though. I have heard many starting problems with the white brothers rev box. I have a magnum rev box with 0 starting problems, and it costs around the same. Maybe somthing you may want to look into;)

[honduh440]

ive got a simular set up and its around 50 degrees outside now and i can barely get mine started after 10 minutes of trying i just deal with it and make sure i am ridding with someone else when i go out so they can pull me

[mojoe2878]

if you still have the stock rev box, put it on and see if it starts any easier, the rev box you have on there know is very bad about making the motor harder to start when it gets colder out.

[Rico]

Originally posted by mojoe2878
if you still have the stock rev box, put it on and see if it starts any easier, the rev box you have on there know is very bad about making the motor harder to start when it gets colder out.

Yuuuuup

Put the stock CDI back in and giver a try...;)

[Toadz400]

I have a WB CDI box and my battery isn't even that great, and it still starts good in the winter...but right now it isn't starting good because I haven't rejetted. That's why I was suggesting he check his jetting, because he mentioned that his battery is fully charged and holds it's charge.

[motoboy66]

I have the same rev box, took the pos off. I had the same issues with it not wanting to start. If I put a battery charger on it, it would fire right up. This almost cost me a few races, good thing someone had some jumper cables. The rev box just doesn't give enough spark unless your battery is 100%. Once started, it did work ok. One day when it wouldn't start, I put the stock back on, and it fired right up. Good Bye White Brothers.

[SnowFlake]

Do any of you rejet for the cold weather? And what do you think i should got to?
i have a stock set up besides an air filter and he baffle is out og my exhaust.

[tim-4par]

I put the stock rev box on.... to no avail. Even changed my plug. Drained the tank. Put new petro in. 110. Trying to see figure this thing out. Any other suggestions? Are there any good jetting articles? I can do the mechanical part, just need to figure out what to change/ adjust it too. Gotta get a tach too..... Thanks, Tim

[AAAirbooorn]

Make sure your gas line is clean.Clean the carb out.Check for wear

[balls2da-wall]

Same thing happened to me the first winter I had my 400ex...it was terribly hard to start so finally I went to the dealer and they gave me a hotter plug...and bingo, problem fixed. Just dont forget to swap back in the summer or you might detonate:D

[Ketch]

Tim what carb are you running first? And then what are your jet
sizes now? Your set up very close to what I'm runing. But i have
39 FCR and the jetting is 55 pj 178main it strarts up with out to
much trouble and it has a big gun box too. I'm at sea level
and during summer months i change back to 52 pj. Jimmy

[motoboy66]

i have a #42 pilot with a 165 main. I do rejet for winter. My dealer said that maybe my rectafier is going out and thatwould also cause hard starts. It starts fine with the stock CDI though.

[tim-4par]

OK. I'm going to try the jetting thing. Never did it before. Any suggestions? I have the Honda service Manual. I am very mechanically inclined. Just not sure what to start with. I have the stock carb on it. I've checked the gas line. Cleaned the air filter, etc. One of my friends had initially jetted it for me. Not sure what's in there. Guess I'll find out. Thanks for all the help. Tim

[Ketch]

Ok Tim get your carb apart look and see what pj is in it. It should be at least a 42 but don't be surprised you going to need next size is a 45 I think. Start there first also look what main you have
now and see if needs to be changed it too. Should be a 170 to 180 main. Jimmy

[tim-4par]

OK. Thanks for all the help. I'm going to be gone for about 2 weeks. Going to see the in laws for Christmas! Yeee Haaaa! I'm going to take the carb apart as soon as I get back and do the jetting thing. Thanks. Tim

[tim-4par]

Sorry for the break. Had to fly away for a bit to do the in law thing! WEEE! OK. I got the carb apart. Everything looks to be good. No big corrosion or anything else. Jets look good. Seats look fine....I have the stock carb, by the way. I have a 170 main and a 38 pj. Is the PJ too small? What should I go to? It does seem to run bit lean. The plug is always brown. Any suggetsions? Jimmy?

[Toadz400]

What's the temp there? If it's in the lower temps I'd move up to a 42 pilot, especially if you have a pipe.

[tim-4par]

OK. I tried going to a 40 pj. Nada. One of the guys at the local bike shop said it could be the battery. Said that due to the high compression and the cam it would be hard to start if the battery's not up to 100%. The battery holds a charge and checks out good on a load tester. It is about 1 year old now. I has been drained more than a few times. Anyone know if an Optima battery is good?

[hondarider2006]

Originally posted by tim-4par
OK. I tried going to a 40 pj. Nada. One of the guys at the local bike shop said it could be the battery. Said that due to the high compression and the cam it would be hard to start if the battery's not up to 100%. The battery holds a charge and checks out good on a load tester. It is about 1 year old now. I has been drained more than a few times. Anyone know if an Optima battery is good?

How many turns out on the air/mixture screw did you go? Try the 42, if that still doesn't work...than I think you have something else thats not carb related. Go about 2-2 1/2 turns out and see how that does.

[tim-4par]

Tried the 42pj. Nope. No luck. I went 2 1/2 turns out. Nada. Ran the battery down again. :( Getting a little frustrated. I'm gonna switch back to the original 38pj and bump start the thing. Any more suggestions? Thanks for all the help from everyone.:mad:

[Toadz400]

Hook the battery up to a battery charger when you are trying to start it so it doesn't drain as badly. Try sticking the stock rev box back on and see if that does anything.

[tim-4par]

I left the 42pj in. Stayed at 2 1/2 turns out. Pull started with no problem. Ran for about 5 minutes. No backfiring anything. Seemed like throttle response was faster with a harder hit. The stock rev box is on. Haven't put the White Bros. box on again. I shut the bike off. Tried to battery start it. Nothing. I think I'm going to try a new battery next this one has been ran down more than a half dozen times.

[Toadz400]

Is the engine turning over at all? Or when you hit the button absolutely nothing happens? Your solenoid could be dirty and needs to be cleaned, the little cylinder-shaped black thing next to the battery is what I'm talking about...might have a different name. Clean the connections on it and see if that helps.

[throwinitup]

yeah take the solenoid apart and use sandpaper and a wire brush to clean it up and then use dielectric grease and do it to it, and electrical tape the rubber boots in place...put a new fuse in for the hell of it too...

ok if you do that and there is still nothing, take a PLASTIC OR WOOD handled screw driver and make contact between the positive and negative lead on the solenoid...itll spark and should turn the starter motor over....

[tim-4par]

The battery will crank the thing over. No problems there. Until I drain the battery down. Tried it last night. Ran the battery down until it wouldn't crank the engine over anymore. Got out the multi meter. Reading 11.94 volts. Gotta be the battery. 12v is good (as pre the boook). The battery is over a year old and has been drained at least half a dozen times. I'm looking into getting an Optima now. Maybe the upgraded one from Pappy.

[Ketch]

Try jumping it from a truck or car you should get full power then.
Jimmy