Jump to content
Sign in to follow this  

Clouds of smoke!!!???

Recommended Posts

Today my and my buddy were racing are bikes down a big straight and at about 75 mph he was ahead of me so I could here my bike very well so I ended up riding the rev limiter for about 3 seconds and my bike blew a huge cloud of white smoke and continued to blow purple smoke for about another 20 seconds or so and then stoped and sisnt do it any more even when I revved it up. The bike has over 4000 miles (almost 200hrs.) and is still on the original valves, piston, and rings. The bike doesnt burn ANY oil and still runs very strong! (thank you KTM and Motorex) So this being the first time this has ever happened Im a little freaked. Any answers to this would be great. Also I had the head off the bike a few weaks ago and I didnt didnt check the ring clearence but every thing looked brand new in there so Im thinking the riings still might be good.

By the way my buddy on his CR250 only beat me on my 250 XCF by 1 bike length on pavement both bikes had pipe and jetting 2-smoke got nothing on the thumpers.:)

Share this post


Link to post
Share on other sites

Dont listen to cr250rman he will tell you he beat me by more but he didnt . he lies. thumpers rule. 2 strokes are cool to though. thanks for any advice guys:ride: :)

Share this post


Link to post
Share on other sites

sure it wasnt black smoke? the rev limiter cuts the spark so u are still sucking in extra amounts of fuel that arent being burned due to the lack of spark. it was probably just excess fuel

Share this post


Link to post
Share on other sites

More like 2 or 3 lengths. Just wit till a get my bore :). Were pretty badass for doing that trail down below.

Share this post


Link to post
Share on other sites

Your bike can just talk to the back side of the 450 when I blow you away!!! And you know it was 1 length the 250F was runnin up your tail pipe.:)

Share this post


Link to post
Share on other sites

We will just post a video of us racing and then the countenance of the thumper will be revealed.

Share this post


Link to post
Share on other sites

Stick in a new piston/rings. It is due at 200 hrs. Rev limiter shouldn't produce any smoke.

Hone your cylinder and do the dry rebuild. You won't regret it. Your motor will run stronger and be cleaner inside because of perfect ring seal.

Hone the cylinder (ball hone or brush hone) in soap/water. Clean out with break clean and paper towels until there is no black on the paper towels. I have a 3.5” ball hone in 180 grit. --- This hone size is for a 250f, you would want to find a hone that is approx 0.5" larger than the bore size of your bike. You don't want the hone much bigger than 1/2" larger than the bore size. And no smaller than 1/4" larger than the bore size.

Wash the piston/rings in soap/water, spray off with break clean and let air dry.

Install the rings on the piston. Use proper ring staggering - follow the manuals staggering method - Be really careful not to get any oil residue on the piston, rings, or cylinder. Keep your hands wahsed

Install one clip on the piston. - the right side one.

Install the piston on the rod, use a light coat of oil on the wrist pin only.

Install the other clip, be sure not to get any oil residue on piston/cylinder.

Install the piston in the cylinder. Compress the rings with your hands and very carefully install it. Be sure that the oil ring doesn't bend over.

With the motor together, and no crankcase oil rotate it 50 times. Then fill with oil and check all fluid levels

Do not start the bike until you intend to ride it. Start it up, let it warm up good, go ride it hard with engine breaking, this will ensure the ring seal.

Share this post


Link to post
Share on other sites

my bike blows blue when it hits the limiter...i notice the proes bikes dont though

Share this post


Link to post
Share on other sites

I am on the limiter many times per lap on the track, no smoke what so ever coming from my bike. I have done starts - rev limit there, no smoke either. And I did hit the rev limit once when sitting at a stand still after it had warmed up after I re rung my piston with the dry method, I was just testing the throttle response, the response was amazing. Sailed right to the limiter :)

Share this post


Link to post
Share on other sites
More like 2 or 3 lengths. Just wit till a get my bore :). Were pretty badass for doing that trail down below.

cr250rman make sure you always have a tow strap with you when riding with these KTM guys. They always seem to need a Honda to tow them home. :D

Share this post


Link to post
Share on other sites

Hey old man tell me that when you put over 200 hrs. of hard riding on a KTM and it doesn't so much as hicup:prof: . Honda guys these days........:):D

Share this post


Link to post
Share on other sites

Hey old man tell me that when you put over 200 hrs. of hard riding on a KTM and it doesn't so much as hicup:p . Honda guys these days........:):D

Share this post


Link to post
Share on other sites
cr250rman make sure you always have a tow strap with you when riding with these KTM guys. They always seem to need a Honda to tow them home. :ride:

i saw that picture on some other form and ur right :):D:worthy:

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Reply with:

Sign in to follow this  

×
×
  • Create New...