Had a Major piston seize, Bored the sleeve to O'40 replaced the piston, rings and roller bearing. Before installing them i coated them with 2 stroke oil. Put everything back together. Started bike everything seemed ok. Bike idled for about 10 minutes no problems switched it off, started again alot of smoke came from exhaust not the normal amount of smoke from the 2stroke engine much much more. Took it for a spin and the bike smothers when i accelerate.. Don't know where to start looking?? Any ideas
2001 Yamaha Blaster Rebuild Failure
- Thread starter Delano
- Start date
The piston is proX piston i bought and the arrow on the piston points forward. By intake you mean the read valves??? Have not fiddled with the jets planning to though unless advised otherwise
Yes intake as in facing the reeds, but if the arrow on the piston faces the front of the motor as you say - its installed correctly. Are you running premix (i.e oil pump block off) or still using the stock oil injection system? Some people make the mistake of running premixed fuel in stock blasters, not realizing they have auto-lube system...
I'm still using the "bum bottle" auto -lube system..
I have double checked everything except for the carb. Checked the plug as well.
Followed all the feeding hoses none are pinched or leaking.. I just don't get the smothering part when accelerating.
I have double checked everything except for the carb. Checked the plug as well.
Followed all the feeding hoses none are pinched or leaking.. I just don't get the smothering part when accelerating.
Did you do proper break-in / heat cycles and the re-torque head/cyl ? Doesn't sound like you have. Did you start with fresh fuel? Do a leak-down test? How long was it torn down? Might have a mouse nest in the pipe.
Ok thanks guys i will do all of the above and definitively do the leakage test...The air filter is brand new and fitted when i did the piston job. Whats the procedure on doing a break in??
Copy-pasted this break-in procedure...
"1) Assemble the engine properly and torque all fasteners to specs.
2) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the radiator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), shut it off.
3) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.
4) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), shut it off.
5) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.
6) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), take the bike off the stand and put it in gear. Take it for a ride. During this ride you want to keep the engine under a load at all times. Do not coast. Do not let the bike idle. Do not allow the engine to stay at one RPM. Riding on a mild slope is fine for this, as is slightly dragging the rear brake the entire time. Do this for about 15-20 minutes. Then shut the bike off.
7) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.
8 ) Re-torque the head and base nuts.
9) Go ride.
The cool-down steps are crucial to this operation. You must let the engine cool completely for the break in process to work properly.
Also, do the warm up procedure I outline here before EVERY ride. Your top ends will last much longer if you do."
"1) Assemble the engine properly and torque all fasteners to specs.
2) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the radiator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), shut it off.
3) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.
4) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), shut it off.
5) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.
6) Start the engine with the bike on a stand and allow the engine to come up to operating temperature (top of the raidator hot to the touch). Do not allow the engine to run at one RPM at all. Constantly vary the RPM and do not allow the engine to idle. When then engine reaches operating temperature (about 3 to 5 minutes of running time), take the bike off the stand and put it in gear. Take it for a ride. During this ride you want to keep the engine under a load at all times. Do not coast. Do not let the bike idle. Do not allow the engine to stay at one RPM. Riding on a mild slope is fine for this, as is slightly dragging the rear brake the entire time. Do this for about 15-20 minutes. Then shut the bike off.
7) Let the engine cool completely (at LEAST one hour). You want the engine to be dead-stone cold. Longer is better.
8 ) Re-torque the head and base nuts.
9) Go ride.
The cool-down steps are crucial to this operation. You must let the engine cool completely for the break in process to work properly.
Also, do the warm up procedure I outline here before EVERY ride. Your top ends will last much longer if you do."
Will do all of the above as instructed...Do you think that the huge amounts of smoke could be related to the skipping of the above mentioned procedures
Also, I recommend not breaking in with amsoil or klotz. I have heard of people not being able to get the rings to seat properly...to slippery. And I would also recommend eliminating your oil pump, seems like they are junk and its a very simply job that really seemed to make my stock 01 run better. The guy I bought from was using the pump and running ams 40:1 in the fuel. I immediately put fresh fuel in it but still thought it seemed sluggish. Cut the lines and plugged them up and ha e been very happy with the result. I need to buy the block off plate yet, but they are like $8 shipped from ebay.
Did it just sieze or were there pieces unaccounted for?
It sounds like you're downing transmission fluid. That happens when a case breaks because part of the piston got against the case and crankshaft and the case broke outwards. A leakdown test will confirm a leaking bottom end... soapy water solution will bubble from the end of the transmission vent hose if the case is broken/clutch side seal is leaking.
Teflon, that sounds like the break-in procedure on a liquid cooled 4 joke. That's not the procedure I've used on my engines and I've had VERY good service. There are a few things you need first though... You have to make sure the pilot jet is VERY clean and the choke o-ring isn't leaking (so you know the idle mixture is correct) then you need to turn the air needle out 1.5 turns from a light seat and MAKE SURE you have no engine air leaksby using a leak down tester to confirm absolutely, you have NO air leaks. Assuming you don't doesn't cut it...
Once you know the idle mixture is going to be correct, I set a fan beside the engine (a simple desk fan or box fan will work, just SOMETHING to circulate air) and start it up and let it idle for 10 minutes or until the cooling fins are hot to the touch. Then I shut it down and walk away for 30 minutes or more (to let it cool back off) and restart it and let it idle for 10 more minutes.
The reason is this... the heat cycles have nothing to do with the pistons and there is no oil ring on a blaster engine to worry about "loading" by never keeping the engine at a given RPM.... the heat cycles are for the gaskets! You need to heat the gaskets to get them to compress and take the first time without riding it and by just letting it idle until it's hot. Then you re-torque everything to make sure it all buttoned up for the ride.
Once I've got the heat cycles done on it, I TEAR OUT! Drive it like I stole it, go spin donuts and run all around everywhere I can as fast as I can on it. Once the gaskets are heatcycled and fasteners retorqued, the harder you run it the better off you are because you have a limited amount of time the cross-hatches are going to last until they're wore smooth and you want those rings to seat as securely as possible as quickly as possible.
Has served me well thus far.
Break In Secrets--How To Break In New Motorcycle and Car Engines For More Power
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