400ex blowing blue smoke

[pighater400ex]

Ok I know theres other posts like this but mine is a bit different. I recently noticed that my 2001 400ex has been putting out small amounts of blue smoke when i get on it. My friend noticed about a week after I put my white brothers e series on, I am running 4 discs and no spark arrestor and a k&n air filter with pre filter and airbox lid on. I was running 10w 30 oil, and read I should run 20w 50 so i changed the oil to 20w 50 and I rode it home a couple miles and didnt notice it smoke at all then today it started smoking some more so Im not sure if its the rings, valve seals or jetting so any advice or input Is very apreciated Thanks

[dave07ex]

It's kinda tough to determine where the oil is getting into the combustion chamber without somewhat of a tear-down unfortunately. Can you provide more details about your quad? How old is it? Was the motor ever rebuilt? Do you know about the maintenance records for it?

[CJM]

Its pretty much a given:
1. Smoke when you start it up means the valve seals are no good, it smokes very little and goes away when it warms up.

2. Smoke when you get on it or all the time means rings always.

Chances are you need new rings. Run a compression test (you can get the tool from harbor freight or rent it from an autoparts store or have a dealer check it for you). If its under 100 psi your compression is low and the rings are bad. Even more so when you add a capful (quart size) of oil to the cyl and it raises the comp reading.

But Id bet my money on rings.

[pighater400ex]

Its really rich and I talked to my local dealer and he said that could be it also I havent lost anypower.

[rooster300ex]

Did u rejet the carb for the increased airflow. Could of make it run lean if u didn't and smoked the rings. Possible if u didn't rejet.

[pighater400ex]

I didn't rejet I was ordering the jet kit and then it started smoking, but what I dont understand is it still has so much power I havent felt any power loss at all , so I think Im gonna rebuild the carb and jet it what do you guys think ?

[CJM]

Id check your plug, you want the electrode tan. Any other color, black=rich, white=lean is not good.

[pighater400ex]

Alright Ill check it tomorrow and let you know

[pighater400ex]

well we couldnt get the spark plug out today but my dad said that the looks of the exhaust where it slips on to the header and there is alot of black soot so he said its rich and we are gonna pull the spark plug out with a special tool he has this week so I ordered the jet kit and my steering stem is bent BAD where it meets the clamp so I have to get one of those too but the plastic is stripped off and we are gonna jet it later this week when the parts come in ?

[rooster300ex]

Originally posted by pighater400ex
well we couldnt get the spark plug out today but my dad said that the looks of the exhaust where it slips on to the header and there is alot of black soot so he said its rich and we are gonna pull the spark plug out with a special tool he has this week so I ordered the jet kit and my steering stem is bent BAD where it meets the clamp so I have to get one of those too but the plastic is stripped off and we are gonna jet it later this week when the parts come in ?

There is gonna be black soot(carbon) in any exhaust. Also running lean won't make u loose power it produces more heat. If u didn't rejet when u put the exhaust on it wouldn't be running rich. Stock they are border line lean for emissions. Yea get the jet kit, and check the valve seals and guides and see if it needs re-ringed or bored. Should fix your problem. Oh yea u might have to grind a socket down a bit to get your plug out. I would buy the plug wrench that comes with them stock. Really easy to get the plug out then.

[pighater400ex]

Ya Im gonna have to get that tool but I talked to a guy at the dealer and he said that the fuel air mixture screw needs adjusted

[rooster300ex]

Originally posted by pighater400ex
Ya Im gonna have to get that tool but I talked to a guy at the dealer and he said that the fuel air mixture screw needs adjusted

If u put a K&N filter and an aftermarket exhaust. Your gonna have to adjust that as well as change some other jetting also. As for the air/fuel screw I would turn it out about 2 3/4 to 3 turns out from lighthly seated stock is 2 1/4 FRI.

[pighater400ex]

Ok Ill buy the jet kit

[pighater400ex]

so do you think its running lean

[rooster300ex]

Originally posted by pighater400ex
so do you think its running lean

Very possible. If u added all those things to increase airflow it definietly gonna make your jetting leaner. Check the plug. There is a sticky thread in the 400ex section that shows different plug colors and what it means. If it did lean it out enough it could of cooked your rings if it wasn't smoking before u did all this. If it smokes after its warmed up and u hit it real hard and let all the way off the throttle its prolly rings or seals. I would just jet it up a bit and go from there if its still smoking check topend.

[pighater400ex]

Ok thanks man you really know your stuff haha Ill check it this week and let you know

[pighater400ex]

Also It didnt start smoking until I put the white bros on I had a Pro circuit t4 with no spark arrestor and the k&n was on

[rooster300ex]

Originally posted by pighater400ex
Also It didnt start smoking until I put the white bros on I had a Pro circuit t4 with no spark arrestor and the k&n was on

Hmmm I would still get er jetted alil fatter, and then go from there. PM me or post if u have any questions.

[pighater400ex]

I talked to my friends dad and he races and he said check the spark plug and go from there jet it and see how it is because I had gas in the oil and He thinks that the float could be sticking and the gasket inbetween the cases could need replaced and thats where the smoke is coming from

[rooster300ex]

Originally posted by pighater400ex
I talked to my friends dad and he races and he said check the spark plug and go from there jet it and see how it is because I had gas in the oil and He thinks that the float could be sticking and the gasket inbetween the cases could need replaced and thats where the smoke is coming from

Not likely but could be IDK just giving u my opinion. Hope u get er figured out. If the float is sticking gas will be running out the overflow tube on the carb with the bowl screw tightend. I just had that issue with a 300ex I got running.

[pighater400ex]

We put a new sParkplug in it and it was a brownish but I rode it again and it is popping when I let off the throttle ?

[rooster300ex]

Originally posted by pighater400ex
We put a new sParkplug in it and it was a brownish but I rode it again and it is popping when I let off the throttle ?

Take the carb off and lightly seat the fuel/air screw and turn it out 3 full turns should fix that popping.

[pighater400ex]

I got it to stop popping but now it wont idle haha just my luck but there is no more blue smoke since I changed the plug it was OLD !!! the previous owner was neglectful

[rooster300ex]

Originally posted by pighater400ex
I got it to stop popping but now it wont idle haha just my luck but there is no more blue smoke since I changed the plug it was OLD !!! the previous owner was neglectful

Hmmm did u clean the carb when u took it off? Just turn the idle up see if that works.

[pighater400ex]

It is 3.5 turns out and still popping so it needs jetted right ?

[rooster300ex]

Originally posted by pighater400ex
It is 3.5 turns out and still popping so it needs jetted right ?

Yea I would say so. Get the next size bigger pilot jet and go from there. Also exhaust leaks especially around the header will make it pop on decel too. Check that first

[pighater400ex]

Ok what about the main jet

[CJM]

See the link in my signature, but basically if the plug is a tannish to chocolate brown your mains fine.

[rooster300ex]

Originally posted by CJM
See the link in my signature, but basically if the plug is a tannish to chocolate brown your mains fine.

Lots of info there for ya

[pighater400ex]

Ya that helps so much thanks for everyones help Ill let you guys know when I get it running right

[rooster300ex]

Originally posted by pighater400ex
Ya that helps so much thanks for everyones help Ill let you guys know when I get it running right

Alrighty man. Enough trial & error u'll get er running right. I know alot of people say that dynojet jet kits suck, but I disagree It has A needle, jets and instrus on which jets to put in with what your running. Being with the lid, with out it if u have an aftermarket pipe,elev. etc. It was worth the pain in the *** to me, and my quad runs perfect.

[pighater400ex]

You guys are gonna hate to hear this but it wont start the jets are gonna be here tomorrow I pulled the new plug off and its rich, I dont have a compression tester at my house but I will saturday hopefully. I stuck my thumb over the spark plug hole and It pushed my thumb off but the next two times I tried it felt weaker but still had air pushing out so any ideas :D I thought I had it figured out but I guess not haha:confused:

[rooster300ex]

Originally posted by pighater400ex
You guys are gonna hate to hear this but it wont start the jets are gonna be here tomorrow I pulled the new plug off and its rich, I dont have a compression tester at my house but I will saturday hopefully. I stuck my thumb over the spark plug hole and It pushed my thumb off but the next two times I tried it felt weaker but still had air pushing out so any ideas :D I thought I had it figured out but I guess not haha:confused:

Dang man. Prolly rings the whole time. U putting that exhaust and k&n and not jetting cooked your rings. Did u go with the dynojet kit??

[pighater400ex]

Thats what Im thinking but Im wondering about the new plug we put in. But its prbly the rings. I went to jets r us and bought a 155 main and a 42 pilot

[rooster300ex]

If it smokes all the time and smells like oil its ur rings. Might even need a bore and new piston. If u do go with the wiseco 11:1

[pighater400ex]

Ya if it needs new rings Ill get the new piston and maybe go 416 but it doesn't smoke bad I can't notice it now but my jets should be here in about an hour so Ill put it all back together and I might put the old plug in it.

[pighater400ex]

do you think Ill need to adjust the needle ?

[rooster300ex]

Originally posted by pighater400ex
do you think Ill need to adjust the needle ?

If u adjust the needle clip down it will also lets more fuel in from the main, so prolly not since u are putting a bigger main in. But like I said trial and error. The more u take your carb off the easier it gets. U might have to take it off several times before u get it right

[pighater400ex]

Alright thanks, I was looking out the window and saw the mail man ran out there and no jets :mad: but there at the post office so I might have to go pick em up but Im gonna jet it and put the carb back on and see if I can get it running

[rooster300ex]

Get a new stock ngk plug after u jet it. Don't put the old one back in.

[pighater400ex]

Ok it will be put back together today and Ill let you guys know if I get it started

[rooster300ex]

ok

[pighater400ex]

IT RUNS!!!! Its running great I just need to tune it

[rooster300ex]

Originally posted by pighater400ex
IT RUNS!!!! Its running great I just need to tune it

Good deal what all did u have to do??

[pighater400ex]

I just cleaned the carb and the screen on the petcock, basically just cleaned it all up and its running great :D

[rooster300ex]

Good deal. And U learned a few things about your quad.

[pighater400ex]

So I rode it to my friends house a couple miles away and he said it was smoking when I pulled in well I thought he was kidding so he rode it and I didnt see anything well another friend rode and sure enough there was some smoke but seemed like more this time and he thinks its rings so Im thinking 416 ?

[CJM]

Do a compression test man. 128 psi is the specified number, but anything less than 100 or close to it would indicate rings.

Also, you checking your oil? Is any missing after you ride?

[pighater400ex]

Thats what were gonna do but the piece to go in the sparkplug hole where can I get one of those. Its so deep on it I dont think it will fit down there

[pighater400ex]

From what it looks like its not using oil

[CJM]

Originally posted by pighater400ex
Thats what were gonna do but the piece to go in the sparkplug hole where can I get one of those. Its so deep on it I dont think it will fit down there

Harbor freight sells a set you can buy that has attachments. Same set i use and it works. You need one that screws in my hand-not the kind that tightens with a wrench.

[pighater400ex]

Ok

[02 trx400ex]

Hi I have a 2002 honda trx400ex it has a dg exhaust and a hot cam and apparently a chip it is blowing smoke and leaving a black residu on my block on the right side by the pipe. It is also going threw oil. I havent noticed lose in power can some one please give me a idea of were ro start dont wanna put money in the wrong place. Thank you