Replaced Valve seals, now smoking worse

[curlyatju]

I have a 06 400ex that recently started smoking. It was blue smoke and mostly when i was at wide upen throttle or when I let off. I read other posts and hoped it would just be the seals. So I changed them out. I didn't have a valve spring compressor so I had a shop do it for 30 bucks after I already had the head off. The guy said it needs new valves too. Is this possible for an 06? It has been rode hard and in sand mostly. I put it all back together without new valves and now it seems like its smoking worse. Is it most likely the rings? Should I go ahead and do the valves too? If im gonna do rings, should I just get a 416 piston and bore it out? How much could I expect to pay for a 416 piston and bore and a valve job. Would any of this be covered under warranty. Thanks for all yall help I know its a long post.

[hornetgod13]

I have an 06' as well. Mine smoked on start up and throttle blips at idle. The smoke was white. My compression check numbers where low but, with in limits. I went ahead and changed both my valve seals and bored and honed the cylinder up to a 416cc size. I did all the work myself with the exception of the bore and hone.
I purchased a valve spring compression tool off Ebay for less than $20.00. If you have basic hand tools and a 400EX maintenance manual you could save yourself a ton of money and do all the work yourself rather than paying someone $50.00 to $70.00 an hour. I doubt the valves are bad. Mine looked good other than carbon build up.
Based on what you described it sounds like your pistion rings are shot. I'm pretty sure this won't be cover by a warranty.

[REDRIDDER]

do you check your valve seats?

[curlyatju]

no didn't check valve seats. don't really know how to. hornet what did it run you to bore the cylinder. how hard was it to put in new piston and rings?

[hornetgod13]

Originally posted by curlyatju
no didn't check valve seats. don't really know how to. hornet what did it run you to bore the cylinder. how hard was it to put in new piston and rings?

The bore and hone to 87mm (416cc) cost me $75.00 but, you might be able to find a cheaper place than I did. The piston and ring kit cost $105.00. The piston was pretty easy for me but, I'm an aircraft mechanic.

[curlyatju]

thats pretty cheap for the 416 kit aint it. the ones i saw on ebay are all over 150. what brand did you get and what compression. If I do this I was gonna do a stage 2 hotcams as i already have filter and exhaust. any other mods that shoud go with this such as hd studs or timing chain. How was the power increase coming from just a pipe and filter. Have you noticed it running any hotter, cause mine already runs hot down here in florida.

[hornetgod13]

I bought the Wiseco 11:1 Hi-Compression piston kit off Ebay. I installed a Stage 1 Hotcam and HD timing chain. I didn't install HD studs but, if you go and higher than a 416 or 11:1 you would definitely want to install them.
I did a lot of mods at the same time so it hard to tell what mods had the most effect but, it runs like a beast now. It's like riding a new totally different quad.
I know how hot it is in Florida. I'm in Key West for the next couple weeks.