CRF250R Help?

[PALMER84ONE]

You'll be buying a new head and piston again if you don't invest in the bottom end. Crank rebuild with new rod and bearings right around $200.

Only when you do it yourself Mike. There are moto riders, and moto mechanic riders. Take Pat for instance, he takes his bike to the shop just tho have the air rotated in his tires. If he wasn't good friends with the owner, you know that job would cost a lot more than a handi.

 

[skedhead]

No, we would gladly put the bottom end in, as we have before in other bikes. The vertical play was within spec and the bike hasn't been ridden hard at all. All trail hours, I've personally never even hit the rev limiter on it.

 

[2Wheels]

They sure last a lot longer that way. Only if you are orig owner can you be sure of how it's been treated. That's why all my used buys get a full rebuild and a meter. Doesn't take long to rack up the hrs either.

 

[Mihylo33]

No, we would gladly put the bottom end in, as we have before in other bikes. The vertical play was within spec and the bike hasn't been ridden hard at all. All trail hours, I've personally never even hit the rev limiter on it.

A full rebuild is the way to go period. If the seal is torn or worn there's a good chance the bearing has gone south or getting ready to go south. That's 41 yrs of dirt scooter experience talking and not a guess.

 

[skedhead]

Welp, just took apart the flywheel part of the case and it turns out we found the issue (we think). One of the plastic shafts (the only removable one) that guide the cam chain didnt go into the correct holding place located by the flywheel, it was resting against the balancer. So what I think was happening (just a guess), is that the shaft was pushing the balancer hard enough to let oil by (the chain guide was stiff as hell, enough to push the balancer). We are going to replace all the bearings we can while the covers are off Balancer bearing and seals, kickstarter seals etc etc...

 

[PALMER84ONE]

You are better off splitting the case and rebuilding the entire engine. But go anead and do as you like. That's over 45 years of wrenching talking and not a guess.

 

[skedhead]

You are better off splitting the case and rebuilding the entire engine. But go anead and do as you like. That's over 45 years of wrenching talking and not a guess.

Yes I understand that. You and 2 other people have told me this multiple times throughout this thread. It isnt my decision to not fully rebuilt it. My dad is tight on money and I would like to ride it before the school year starts. If it blows up in 4 months whatever, at least I got to ride for that time.

 

[Mihylo33]

Yes I understand that. You and 2 other people have told me this multiple times throughout this thread. It isnt my decision to not fully rebuilt it. My dad is tight on money and I would like to ride it before the school year starts. If it blows up in 4 months whatever, at least I got to ride for that time.

We understand that people can't afford to do a whole lot at once. We are all dads here and have had to make this decision before which is why we know it's cheaper to rebuild it now than wait until later. When one of these 4stroke motors blow it wipes out the entire motor. Not just the bearings it takes the cases, the cylinder, the head, the valves, the piston, the crank, the oil pump, the cam, so the $300 in extra rebuild changes to a 2900 rebuild or a scrap Honda parts bike. Ask @snowflake about his Honda.

 

[SRAD97750]

Hello, I had a re-read on this thread.
The oil being forced out the transmission breather can only be piston blow-by or plugged crankcase vents. (Overservicing?)
Being that the new piston and rings didn't fix it, makes me think a major vent is plugged causing excess crankcase pressure. So, I would re-check the piston ring end gap and verify the crankcase is breathing properly. -BIG DAN

 

[PALMER84ONE]

Yes I understand that. You and 2 other people have told me this multiple times throughout this thread. It isnt my decision to not fully rebuilt it. My dad is tight on money and I would like to ride it before the school year starts. If it blows up in 4 months whatever, at least I got to ride for that time.

Tell pops (and he should know) an extra 2-300 now, is cheaper in the long run.

Unless you are whininig to him that you want to ride before the end of summer and he just can't take it anymore.

We understand that people can't afford to do a whole lot at once. We are all dads here and have had to make this decision before which is why we know it's cheaper to rebuild it now than wait until later. When one of these 4stroke motors blow it wipes out the entire motor. Not just the bearings it takes the cases, the cylinder, the head, the valves, the piston, the crank, the oil pump, the cam, so the $300 in extra rebuild changes to a 2900 rebuild or a scrap Honda parts bike. Ask @snowflake about his Honda.

DITTO!

 

[Redordead89]

Yes I understand that. You and 2 other people have told me this multiple times throughout this thread. It isnt my decision to not fully rebuilt it. My dad is tight on money and I would like to ride it before the school year starts. If it blows up in 4 months whatever, at least I got to ride for that time.

Yes he and 2 others told you multiple times through this thread for a very good reason! if it blows up in 4 minutes, Whatever! Do you have a manual Will?

 

[snowflake]

We understand that people can't afford to do a whole lot at once. We are all dads here and have had to make this decision before which is why we know it's cheaper to rebuild it now than wait until later. When one of these 4stroke motors blow it wipes out the entire motor. Not just the bearings it takes the cases, the cylinder, the head, the valves, the piston, the crank, the oil pump, the cam, so the $300 in extra rebuild changes to a 2900 rebuild or a scrap Honda parts bike. Ask @snowflake about his Honda.

Fuck Honda.

 

[skedhead]

Fuck Honda.

*profile picture is him riding a honda

 

[snowflake]

*profile picture is him riding a honda

Exactly.

 

[skedhead]

Hello, I had a re-read on this thread.
The oil being forced out the transmission breather can only be piston blow-by or plugged crankcase vents. (Overservicing?)
Being that the new piston and rings didn't fix it, makes me think a major vent is plugged causing excess crankcase pressure. So, I would re-check the piston ring end gap and verify the crankcase is breathing properly. -BIG DAN

Although any of that could be possible, the reason I mainly suspect it isn't is because the oil is disappearing from the engine side to the clutch side then being squirted out due to high oil pressure.