1985 yamaha 200 driveability problems

[Walkerallen]

ok guys heres the deal. pull my dads bike out for the first time this year yesterday and this is what i got. it started on like the 1000th pull, wont idle, and looses power and cuts out at about 3/4 throttle, smokes worse than a two stroke.....blue. so i pulled the carb and put it in the dip tank for 26 hour. put it back on, cleaned the air filter,and when i put in new plug in i noticed that there was oil puddled on top of the piston. WTF. this would explain the smoke. so i put it back together and the miss at 3/4 throttle is still there. this is the first time there has even been oil on top of the piston but it has smoked for the past 2 years. but the lose of power really has me stumped. it acts like it is starved for fuel but the float is completely out of adjustment. what can i do now? i need some help......I WANNA RIDE!!!!!

[Walkerallen]

come on guys some must know something i can do

[bcredneck]

get new rings i bet my ass thats it

[Walkerallen]

is there anything i can do to narrow it down to the rings instead of just throwing parts at it and guessing

[bcredneck]

do a comp test or pull the pistion out and take a look and if you get new ones early it may save the pistion and cylinder and if a four stroke smokes 9 times out of 10 it needs rings
and you cant keep turning it over till you know ive turned a broken ring into a way bigger probem by doing that

[ironchop]

get new rings i bet my ass thats it


is there anything i can do to narrow it down to the rings instead of just throwing parts at it and guessing

:lol::lol::lol:...I`m sorry Walker this thread is funny and that line is hilarious

and the only truthful way to acheive that is to get a manual and tear down the topend so you can inspect and know FOR SURE what was causing all those issues

forget about the fueling issue...as long as oil is in the piston, no amount of carb tuning will make it run right

smoking and losing power as symptoms could be a dozen different things and everyone of those are tucked inside the topend of your motor. I wish there was an easy button but there isn`t. A compression tester doesn`t necessarily narrow it down much as the possible culprits are:

bad rings
bent/broken valve
blown head gasket
hole in piston
stuck valve
bad/burnt valves and seats

smoking comes from:
bad valve seals
cracked guides
blown head gaskets
various topend oil feed joints
bent valves (the tip oblongs the seal and leaks)

My advice is don`t buy parts until it`s all apart so you know what you need. Sorry to be blunt but yer gonna have to get a manual and get greasy.

My neighbor bought a $1400 Kawasaki twin short block for his zero-turn mower because someone on the net and a friend confirmed that the lack of compression was because the pistons and rings were bad...he decide to get a new lower so he would`nt have to rebuild the motor for awhile...he paid me to install it...the short block comes without heads....we had to use the heads from the old motor...before I put them on, I inspected the valves...put my thumbs on them and turned...they turned on the seats freely...with the springs still installed...no seal there...moral of the story is a "diagnosis" got him a $1400 bill when all he needed was a valve job, seals, and springs

ya gotta get inside and look to be sure

Post the pics of it. There`s alot fellas here with the experience to help you through it.

[Chazz of Blades]

I prefer throwing a hammer, but to each his own.



Imma have to go with BC on this one, try some new rings(after testing comp of course, and a visual inspection).

[fabiodriven]

Listen to Chazz and BC. One's not old enough to drink and the other, well....

But they are experts at diagnosing problems from the computer. Been doing it for months now.

[ironchop]

Frankly, I give up

[Chazz of Blades]

Listen to Chazz and BC. One's not old enough to drink and the other, well....

But they are experts at diagnosing problems from the computer. Been doing it for months now.

From anyone else that could be a compliment. Touche. :)