Jump to content

rebuild and unbuild again


Slickgib

Recommended Posts

I so i had a new top end done like 3 weeks ago. i heat cycled it the 3 times and everythign seemed good. except i get this one problem. while warming up i bog down and smoke alot. so after my dune trip i took of my cool head and this is what the pistons look like.i cant attach them its to big.. but the top of the piston is black but on the sides it has like regular gray piston coloring like water was getting on there.. how can i upload pictures bigger fyoq5d.jpg both look like that

Link to comment
Share on other sites

i didnt retorque. nor did i rejet anything. i didnt know i would have to rejet after a top end.all i noticed is after it would sit over night and i would start her the next morning she would smoke like some coolent leaked but after 5 minutes of warm up she would run fine. sense i was board when i got home from my trip i pulled the head and noticed the candycane type cylinders.. i torqued it orginally to 20lbs so i hear i could go to 22. so ill re do it. i also wanted to double check everything looked good after the trip i was running pretty hard at some times. i want to install some vforce3 reeds.

Link to comment
Share on other sites

well, you should upp the mains IF you runn more oil than usuall durring break-in to comphensate for the extra oil.....you do your heat cycles with the radiator cap off, then retorque. they will be lose after a couple cycles......i do mine in stages- 10-15# in sequence, then 25-30#...then retorque after the second and fourth heat cycle...i put the cap on after the first retorque......but, i don't use a torque wrench, just by feel, since i'm used to torquing shit all day long at work....

Link to comment
Share on other sites

well, you should upp the mains IF you runn more oil than usuall durring break-in to comphensate for the extra oil.....you do your heat cycles with the radiator cap off, then retorque. they will be lose after a couple cycles......i do mine in stages- 10-15# in sequence, then 25-30#...then retorque after the second and fourth heat cycle...i put the cap on after the first retorque......but, i don't use a torque wrench, just by feel, since i'm used to torquing shit all day long at work....

 

 

So...you retorque the head to 25-30#s even though spec is 20 to 22...but you don't use a wrench so you're not sure if they're torqued properly? Do you use a torque wrench at work? :)

Why would you take the cap off? Don't you want to build pressure in the cooling system as well as allow the bike to heat up? You realize that by removing the radiator cap, the system can not get as warm (pressure allows the boiling point to rise vs. a non sealed, non-pressurized system)

 

Guys (not pointed at you AK) running more oil during break in is not only unnecessary, it's a bad idea.

 

The whole point of break in is to file the rough edges off the ring and cylinder to make them "square" to seal against each other. More oil makes it difficult for this to happen, causing cylinder glazing and improper ring seating.

 

It can also gum up the ring lands...making the rings stick and not press against the cylinder.

 

That's a bad picture...but there is either way too much oil, or too much fuel in the fuel/air mixture (jetting).

 

Did you notice any white smoke? Plugs look white? When you released the radiator cap, was the coolant level low?

 

If there are signs of antifreeze being burned...take the cylinders off, take the studs out and put the deck of the cylinder on a surface plate to check for flatness.

Take the domes out of the head, do the same.

 

There is simply no way that piston crown should look like that after such a short time. It's either an oil problem or a fuel/air mixture....that piston should be clean and carbon free...or a VERY minimal amount of carbon build up...

Link to comment
Share on other sites

true, you will boil over before you get it all the way up, however, it is most likely to start a leakpoint while the engine begains to cool, and still pressurized, since everything gets crushed during warm-up, then loosens.......and it loosens significantly. i use a torque wrench alot on mostly cat engines still under warrenty.. i don't personally believe in using extra oil either, i just hear it alot that they were told to, so i leave it alone. good detergency is all you need for break-in. i would actually go strait to plug chop after first retorque for decent ring seat.......oh,and i'm not the only one that over-torques the head, either. it can handle more than that, but wil starte to warp

Link to comment
Share on other sites

yes i ran it alot oiler then usual. but im going to put the head back on and re torque to 22 this time. i only did 20 last time.

 

 

also fyi im getting 155 psi of cpmpression on each side.. i have 22 doomes. is this to much. i have a stock motor with toomey pipes and kn filter

Link to comment
Share on other sites

yes i ran it alot oiler then usual. but im going to put the head back on and re torque to 22 this time. i only did 20 last time.

 

Run the same amount of oil you're normally going to use.

 

I can promise you with 100% certainty, 20 ft. lbs or 22 ft. lbs won't make a bit of difference.

 

I torque mine down in sequence all at 15, then 20 then 22.

Link to comment
Share on other sites

also what kind of oil are you running, i run castor 927 and it is a great oil but does like to settle out when its cold. Make sure you shake the bike really good, then turn your fuel on. Mine will still smoke pretty good when i first start it up but then as it warms up and starts taking the shaken up fuel in it will stop smoking to almost no smoke. Check your coolant level, smell the exhaust (is hard on a two stroke) but it should have a sweet smell to it, also check your transmission fluid and see if it may not be leaking by the crank seal. I also run mine with the cap off for a little while after a rebuild, this prevents an air pocket from building up, and most times you will have to add just a smige of coolant after its been run. If its warm and your breaking it in put a fan in front off it to move some air over the rad as its idling. If you idle it to long it may have a chance off overheating.

 

Just a few thoughts i had.

 

 

 

Cody

Edited by papa_smurf49319
Link to comment
Share on other sites

also what kind of oil are you running, i run castor 927 and it is a great oil but does like to settle out when its cold.

 

Fine point Cody... the oil can settle at the bottom of the tank and that's exactly where the valve is.

A good 10-15 seconds of shake before a ride is a good thing...even though you look like a retard doing it...LOL.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...