Hard Starting? Please Help

[HondaSkidoo]

Hello, I am having a terible time getting my 400ex started. This is my first winter with it. I put a 42 pilot in a few months ago and that really helped. It is around 20 degrees out so it is pretty cold. Should I choke it and give it gas? It did fire up a few times but as soon as I tried to bleep the gas it stalled. I checked the plug and it didn't look real wet.

Any starting tips would be great. Thanks

[Ruby Soho]

when you get it started, put the choke on 3/4 of the way up, and toggle that between full and 3/4, it should stay idle fine for awile, then what i do is give the throttle a few blips, then put the choke off and keep on the throttle very slightly but a constant speed, hard to explain. the engine is cold and doesnt like the cold, and the worst thing you can do is if you get it started is romping on it and riding it like normal as soon as you start it up, you should wait till it will idle on its own with no choke normally.

[HondaSkidoo]

Originally posted by Ruby Soho
when you get it started, put the choke on 3/4 of the way up, and toggle that between full and 3/4, it should stay idle fine for awile, then what i do is give the throttle a few blips, then put the choke off and keep on the throttle very slightly but a constant speed, hard to explain. the engine is cold and doesnt like the cold, and the worst thing you can do is if you get it started is romping on it and riding it like normal as soon as you start it up, you should wait till it will idle on its own with no choke normally.

So should I start with the choke on and when it starts move it to 3/4? Should I give it a few shots of gas? Up until today I would use no choke and just give it a few shots of gas. Thanks

[AbnMP13]

Like you I put in a 42 last week, since then I have not choked it and it's been in the 30's. I pump the gas 3-5 times, hit the button and when it turns over I start playing with the throttle but I have not had to use the choke yet. But I do have to repeat the above process usually 2 or 3 times.

[JDMThoughts]

The 400EX is a piece of **** to start. I haven't been able to start mine in so long it's not funny anymore. I have tried all of the above methods with no success. I have stock carb and jetting configuration new plug new air filter and new battery. Nothing will make mine start. If you wanna ride in the winter, then get rid of your 400EX.

[Honda#4]

You don't have to use the choke if you put in a 42 pilot at least I never have yet. Hondaskidoo what is your current jetting?

JDMThoughts maybe your bike is'nt properly jetted right, if you give me your mods to your bike I could help you so it runs alot better. If you want help.

[JDMThoughts]

Oh no the bike is jetted correctly. I have set it back to stock twice. I brought the bike to a shop and the mechanic there turned the screw out like 5 or so turns and I was fouling plugs like crazy. So I said screw that shop and I went back to going over the carb and set it back to 2 1/4 turns. No luck, I went to another shop and I talked to the mechanic who happened to be someone I graduated high school with and he checked the carb out free of charge. He said I had it all perfect. I re-install it still no luck. I bring the bike in and I needed 1 more turn on the screw to get it to wanna run in this cold weather. Along with an adjustment on my throttle. Quad is running for the moment. As for mods, they are in my sig. I only have a Uni filter, something that isn't worth jetting for. So far it's now running, but who knows what the story will be next weekend.

[HondaSkidoo]

[QUOTE]Originally posted by Honda#4
[B]You don't have to use the choke if you put in a 42 pilot at least I never have yet. Hondaskidoo what is your current jetting?

I have what is recommended from the DynoJet kit which I believe is the DJ170 main, DJ needle on the 3 notch. I have a 2" exhaust insert, a K & N filter with a open lid air box. The instructions on the insert said to use the Dynojet for after market. Until it got down to 10 - 20 degrees on this last start it ran 10 times better than stock. Any help is appreciated.

Thanks Rich

[AbnMP13]

Skidoo, put a smaller pilot jet in, I have a full exhaust with the K&N lid and I only run a 160. Try a 155 if you have it.

Check your plug, black means smaller jet.

JDM what size pilot jet do you have? Stock one still?

[HondaSkidoo]

AbnMP13, Are you refering to the DynoJet numbers? I know they are different than others? My plug is a little black, but I was thinking it was because I have been messing around and haven't had any WOT lately. Do you think a smaller pilot jet will halp will help it start?

Thanks

[JDMThoughts]

Originally posted by AbnMP13
JDM what size pilot jet do you have? Stock one still?

Carb is stock, no changes to the jets. Air/Fuel Screw is at 3 1/4 turns.

[AbnMP13]

I would go smaller, if it's too lean it will backfire on deceleration which will give you a better idea of what to do. Mine was backfiring so I turned the fuel screw out more and it stopped. And no I was referring to Keihen numbers.

This chart is from the thread "Confirm Jetting" in the 400EX section:

Dynojet is absolutely correct about the shape of the hole influencing flow characteristics. No smoke and mirror techno-babble there. Nonetheless, there's this chart. It is based on actual measured orifice size.

Dynojets numbers are simply the hole diameter. A 140DJ main has a 1.40mm (0.055") diameter hole in it at the threaded end. A Mikuni 140 has a 140 cc's of fuel flow per minute. I don't know where the Keihin scale comes from.

Width------Keihin # -- DynoJets # -- Mikuni #
0.0350---- 92.5--------- 92----------- 86.3
0.0360---- 95----------- 94----------- 88.1
0.0370---- 97.5--------- 96----------- 90.0
0.0380---- 100---------- 98----------- 91.9
0.0390---- 102.5------- 100---------- 93.8
0.0400---- 105--------- 102---------- 95.6
0.0410---- 107.5------- 104---------- 97.5
0.0420---- 110--------- 106---------- 99.4
0.0430---- 112.5------- 108--------- 101.3
0.0440---- 115--------- 110--------- 103.1
0.0450---- 117.5------- 112--------- 105.0
0.0460---- 120--------- 114--------- 106.9
0.0470---- 122.5------- 116--------- 108.8
0.0480---- 125--------- 118--------- 110.6
0.0490---- 127.5------- 120--------- 112.5
0.0500---- 130--------- 122--------- 114.4
0.0510---- 132.5------- 124--------- 116.3
0.0520---- 135--------- 126--------- 118.1
0.0530---- 137.5------- 128--------- 120.0
0.0540---- 140--------- 130--------- 121.9
0.0550---- 142.5------- 132--------- 123.8
0.0560---- 145--------- 134--------- 125.6
0.0570---- 147.5------- 136--------- 127.5
0.0580---- 150--------- 138--------- 129.4
0.0590---- 152.5------- 140--------- 131.3
0.0600---- 155--------- 142--------- 133.1
0.0610---- 157.5------- 144--------- 135.0
0.0620---- 160--------- 146--------- 136.9
0.0630---- 162.5------- 148--------- 138.8
0.0640---- 165--------- 150--------- 140.6
0.0650---- 167.5------- 152--------- 142.5
0.0660---- 170--------- 154--------- 144.4
0.0670---- 172.5------- 156--------- 146.3
0.0680---- 175--------- 158--------- 148.1
0.0690---- 177.5------- 160--------- 150.0
0.0700---- 180--------- 162--------- 151.9
0.0710---- 182.5------- 164--------- 153.8
0.0720---- 185--------- 166--------- 155.6
0.0730---- 187.5------- 168--------- 157.5
0.0740---- 190--------- 170--------- 159.4
0.0750---- 192.5------- 172--------- 161.3
0.0760---- 195--------- 174--------- 163.1
0.0770---- 197.5------- 176--------- 165.0
0.0780---- 200--------- 178--------- 166.9
0.0790---- 202.5------- 180--------- 168.8
0.0800---- 205--------- 182--------- 170.6
0.0810---- 207.5------- 184--------- 172.5
0.0820---- 210--------- 186--------- 174.4
0.0830---- 212.5------- 188--------- 176.3
0.0840---- 215--------- 190--------- 178.1
0.0850---- 217.5------- 192--------- 180.0
0.0860---- 220--------- 194--------- 181.9
0.0870---- 222.5------- 196--------- 183.7
0.0880---- 225--------- 198--------- 185.6
0.0890---- 227.5------- 200--------- 187.5



Originally posted by HondaSkidoo
AbnMP13, Are you refering to the DynoJet numbers? I know they are different than others? My plug is a little black, but I was thinking it was because I have been messing around and haven't had any WOT lately. Do you think a smaller pilot jet will halp will help it start?

Thanks