Rode New Mexico BDR, Sprained ankle, Broke bike

Rode the NM BDR last month with a buddy. We did it north to south, taking 8 days for the BDR proper. No trucks or trailers on this trip; I rode from home in West TX to NM to meet my bud, then up to the starting point in Antonito CO, mostly following the NM Continental Divide Route. Rode the whole Route without issue until 8 miles from the end in Dell City TX where I went down in deep powder dirt at about 45 MPH. Sprained my ankle and bruised some ribs, but nothing broken on me or the bike. I spent a few days in Dell City to recuperate and then headed for home. I was about 170 miles from home when the bike quit, and I mean QUIT! Luckily I had a cell signal and called a friend who came with a trailer to pick me up. Oh yeah, there was a trailer involved on the trip! The bike has been on the back burner because of other projects, but I got started and dropped the engine today, All clues point to a broken connecting rod. The bike gave up the ghost with 28,875 miles on the odometer,

Not the connecting rod, but the piston. It took the cylinder with it.

Bummer! at least you got a decent final ride in

All things being said and done, where are pics of the trip

Turning aspens near Cuba NM


Desert between Cuba & Grants NM


Early morning sun on my tent, Gila National Forest

Near White Sands Missile Range



The view from the Guadalupe Rim



The only time I dropped the bike on the whole 2500 mile trip. I made it a good one!

Back in business. When I started adding up the cost of rebuild parts, it began to look easier (and maybe cheaper) to just swap in a new motor. I found a brand new motor that came from a 2019 WR and installed it last week.

grw800 wrote:

Back in business. When I started adding up the cost of rebuild parts, it began to look easier (and maybe cheaper) to just swap in a new motor. I found a brand new motor that came from a 2019 WR and installed it last week.

It's never cost-effective rebuilding a motor, but I'm surprised you went for a brand new one; if you don't mind me asking, how much was it?

johnkol wrote:

It's never cost-effective rebuilding a motor, but I'm surprised you went for a brand new one; if you don't mind me asking, how much was it?

I paid $2000 for the new engine. While I could have bought a used one for less, it was worth it to me to not have to wonder about maintenance (or lack thereof) on a used engine.

grw800 wrote:

I paid $2000 for the new engine. While I could have bought a used one for less, it was worth it to me to not have to wonder about maintenance (or lack thereof) on a used engine.

Makes sense, especially if you're planning on keeping the bike for a long time.

Where did you buy it from?

laz749s wrote:

Where did you buy it from?

I decided I would post either the selling price or the seller's name, but not both. Since I've already revealed the price, I'm not going to divulge the seller's name. I think he gave me a good deal, and I don't want anyone to assume that what I paid is the going price for a new motor from  this seller. It's easy enough to find WR250 motors for sale online.

Any idea why the motor failed with only 20k on it???

SLOWRIDER wrote:

Any idea why the motor failed with only 20k on it???

It was 28,875. As one of my friends says, the cause was "a few billion too many revolutions"! I would like to know the cause, but I have no idea why it failed.

OK, I found a possible cause for the failure. I'm taking the old motor apart to investigate, and today I found that  the  plastic oil pump idle gear had lost all its teeth! There are three plastic gears in the oil pump gear train: the drive gear on the back of the clutch shell (AKA primary driven gear), the idle gear, and the gear of the oil pump itself. The two outer gears showed some wear, but the idle gear was completely worn out. So the oil pump wasn't being driven. That would explain the lack of lubrication at the wrist pin! At first I thought that a piece of metal had locked up the oil pump and caused the damage to the idle gear, but the pump spins freely. So it may have happened the other way around:  the idle gear just wasn't spinning the oil pump. I don't know if this is normal wear for a motor with nearly 29,000 miles, but it would sure be a good idea to do an inspection of these plastic gears on a high mileage motor to avoid a catastrophe like mine.

grw800 wrote:

OK, I found a possible cause for the failure. I'm taking the old motor apart to investigate, and today I found that  the  plastic oil pump idle gear had lost all its teeth! There are three plastic gears in the oil pump gear train: the drive gear on the back of the clutch shell (AKA primary driven gear), the idle gear, and the gear of the oil pump itself. The two outer gears showed some wear, but the idle gear was completely worn out. So the oil pump wasn't being driven. That would explain the lack of lubrication at the wrist pin! At first I thought that a piece of metal had locked up the oil pump and caused the damage to the idle gear, but the pump spins freely. So it may have happened the other way around:  the idle gear just wasn't spinning the oil pump. I don't know if this is normal wear for a motor with nearly 29,000 miles, but it would sure be a good idea to do an inspection of these plastic gears on a high mileage motor to avoid a catastrophe like mine.

This is weird since, as you point out, none of the other plastic gears show any corresponding wear. I presume you did not find any plastic debris when you took off the side cover?

It appears that the outer edges of the idle gears are intact, which indicates that it was the clutch basket drive gears that wore out the idle gears. I am willing to bet that this is not normal wear by Yamaha's standards given that the first valve check is at 26k miles; if any plastic gear was a wear item to be replaced at around the same mileage as the first valve check, they would have included it in their check list.