smokey 425 ex

[drftn]

am new to hondas and am buying a 425 kitted trx 400 ex that smokes the guy said that is common for hondas to smoke after an oil change. is this right??? what could it be?? is it an easy fix for a home handy man. any help would be good thanks

[Blue250X]

It is not common to smoke after an oil change. It could be the rings letting oil by. What color is the smoke?

[02440exkid]

well some 1 told me that if you don't chang you oil in a wile the sluge bilds up on the valve seals then you put new oil in it takes it off on it smokes. idk just wut some 1 told me.

[Blue250X]

Originally posted by 02440exkid
well some 1 told me that if you don't chang you oil in a wile the sluge bilds up on the valve seals then you put new oil in it takes it off on it smokes. idk just wut some 1 told me.

I've never heard that, I'm not saying it's true or not, just never heard it. But for "drftn" I am pretty sure that blue smoke is oil, and white smoke is water/coolant (for liquid cooled motors), and black is too much gas or rich jetting. Someone correct me if I'm wrong.

[400eXr1d3rZ]

Originally posted by 02440exkid
well some 1 told me that if you don't chang you oil in a wile the sluge bilds up on the valve seals then you put new oil in it takes it off on it smokes. idk just wut some 1 told me.

no thats not how it goes, its, if you let your quad sit for a while without riding, lets say 3 days. oil will leak into the vavle seals or into the rings, only a little though, and when you start your quad it smokes. not for too long, just untill the oil that leaked is burned out

[drftn]

Hay thanks and yea it is blue smoke and it keeps smoking while your riding, guess i sould be in for a recon.
What make of piston kit would a 425 be? new rings might be a go and i have no way of finding the orignal builder

[GPracer2500]

Originally posted by drftn
Hay thanks and yea it is blue smoke and it keeps smoking while your riding, guess i sould be in for a recon.
What make of piston kit would a 425 be? new rings might be a go and i have no way of finding the orignal builder

A "425" is almost certainly an 88mm piston. 88mm bore and 70mm stroke works out to 425.533cc. Every once in a while you'll see someone refer to a "425" or a "415" (vs. the commonly refered to 416) and it usually just comes down to how you round when doing the displacement calculation. If that's not the explination for what this "425" is then I don't know what it could be.

88mm pistons are a common size for anyone who makes 400EX/XR400 pistons. You'll just have to remove the piston to see who made it. Be aware that 88mm is the last size the stock sleeve will handle. Maybe the bore is OK but I wouldn't bet on it. The next options are 88.5mm (430cc) or 89mm (435cc even though they're almost universally refered to as "440s"). A 89.5mm is a true 440cc. They'll all need a new sleeve pressed in.

ETA: corrected typo

[drftn]

mint good to know

[underpowered]

Originally posted by GPracer2500
88.5mm is a true 440cc. They'll all need a new sleeve pressed in.

little correction, 89.5 is a true 440. GPracer just made a little Typo. 88.5 is a 430 as he stated earlier in his post.


but you need to tear it down to see what brand of piston is in it before you buy rings and to make sure you just need rings, not a new sleeve.

[GPracer2500]

Originally posted by underpowered
little correction, 89.5 is a true 440...

Whoops!

Thanks