Project Rescue Finally Let Go

[MX763]

I went on my weekly ride Thursday and during my second moto the old 250 just died. We wheeled her back to the pit and tore it down to find the skirt broke and sucked it all down in the crank case. So it looks like I am going to need a crank kit and new top end. I am going to have the top end Eric Gorr'd so thats taken care of but the crank......What does the thumper talk brethren recommend for cranks? I had a buddy that went through a few Wiseco cranks in a short span and it seems this is common. Hot Rods? OEM? What say you?

Edited August 13, 2017 by MX763

[zeke383]

Personally, I like OEM or a good OEM core rebuilt with a Pro-X rod kit (currently running this combo). 

[MX763]

19 minutes ago, zeke383 said:

Personally, I like OEM or a good OEM core rebuilt with a Pro-X rod kit (currently running this combo). 

Good stuff! Also, if I go OEM and order the "crank kit"...does it come assembled and balanced?

Edited August 13, 2017 by MX763

[MX763]

I got this thing all apart and ready to split the cases tonight. I bought all OEM parts for the motor. I am going to replace the crank, crank bearings and seals, water pump, water pump bearings and seals. I had the cylinder punched out to a 295, ported along with supporting head mods by Tom Morgan which should be here this week.
I have a feeling it was the crank bearings that seized somehow causing the skirt to break. They smell terrible! The water pump bearings were really tight and they also smell pretty bad. Overall, this whole motor is going to get the revamp....while I was at it I ordered all new Pivot Works wheel bearings, swing arm bearings, shock and linkage bearings and had the forks and shock completely gold valved by Ronnie Monk at Six12.

Questions,

1.) There was no up and down play in the connecting rod.....where can I send the stock crank to have it checked and rebuilt? It might make a nice spare.

2.) Is the OEM Yamaha replacement crank balanced and straight or do I need to keep a close eye on this?

3.) Would it be typical to have piston pieces all over the end of the throwout rod and actuator or is this something else I need to be concerned about?

[nickmell]

That is not piston pieces on the clutch parts. The crank is sealed from the transmission so you have another issue.

[ASP1227]

KenOconnor racing will rebuild your crank

[MX763]

23 hours ago, nickmell said:

That is not piston pieces on the clutch parts. The crank is sealed from the transmission so you have another issue.

 

That's what I thought! Those were all soft little pieces so they were probably clutch. The clutch plates did not look like the have been ate up nor did the old clutch. 

[Smoking 2's]

Those studs that hold the jug down look near rusted thru on the one anyways if I'm seeing that right

[YZDOC]

I believe crank works rebuilds cranks also. 

Replace all questionable parts for piece of mind.

[Motox367]

On 8/30/2017 at 8:19 AM, MX763 said:

I got this thing all apart and ready to split the cases tonight. I bought all OEM parts for the motor. I am going to replace the crank, crank bearings and seals, water pump, water pump bearings and seals. I had the cylinder punched out to a 295, ported along with supporting head mods by Tom Morgan which should be here this week.
I have a feeling it was the crank bearings that seized somehow causing the skirt to break. They smell terrible! The water pump bearings were really tight and they also smell pretty bad. Overall, this whole motor is going to get the revamp....while I was at it I ordered all new Pivot Works wheel bearings, swing arm bearings, shock and linkage bearings and had the forks and shock completely gold valved by Ronnie Monk at Six12.

Questions,

1.) There was no up and down play in the connecting rod.....where can I send the stock crank to have it checked and rebuilt? It might make a nice spare.

2.) Is the OEM Yamaha replacement crank balanced and straight or do I need to keep a close eye on this?

3.) Would it be typical to have piston pieces all over the end of the throwout rod and actuator or is this something else I need to be concerned about?

Looks like aluminium  take good look for broken peice off basket, inner hub, pressure plate. If not any of them may be in tranny 

[MX763]

I finally got this thing together and it feels like transmission is bound up. The shifter will only move as far as it would if I were in first gear and kicking down. I have rebuilt the shifting mechanism twice and nothing. Do I need to resplit the cases and remove/reinstall the transmission? 

[YZDOC]

Did you split the cases and get a good look at the transmission before you put it back together from previous photos?

I'm going to say, there is alot of factors in the amount of material you showed on the photos. The bearing carrier/cage on the other side of the clutch is what I would think is done. Only way to do things right is to split case and rebuild with all new bearings and seals along with all parts that are worn out. 

[MX763]

4 minutes ago, 2 STOKE YZ DOC said:

Did you split the cases and get a good look at the transmission before you put it back together from previous photos?

I'm going to say, there is alot of factors in the amount of material you showed on the photos. The bearing carrier/cage on the other side of the clutch is what I would think is done. Only way to do things right is to split case and rebuild with all new bearings and seals along with all parts that are worn out. 

All of the gears were insepcted and there was no visible damage to any of the gears. Every bearing and seal was replaced as well as the crank assembly and piston. The transmission was a bit of a bitch to get back in there and I am afraid something moved when we were putting it back together.

[YZDOC]

1 minute ago, MX763 said:

All of the gears were insepcted and there was no visible damage to any of the gears. Every bearing and seal was replaced as well as the crank assembly and piston. The transmission was a bit of a bitch to get back in there and I am afraid something moved when we were putting it back together.

Forks are hard to put in wrong. If they are on the gear, and in the drum it should look and shift proper. L and R can be mixed but you would see it's not lined in the drum.

You have the segment/pawls/springs, and collar on the assembaly, and the shift shaft properly placed?

Are you shifting and moving the transmission gears at the same time? 

If the bike is not running, it can be deceiving on proper shifting.

Are you using a magnetic drain plug that is hitting the shift drum? 

Just asking, see if we can help...

[MX763]

11 minutes ago, 2 STOKE YZ DOC said:

Forks are hard to put in wrong. If they are on the gear, and in the drum it should look and shift proper. L and R can be mixed but you would see it's not lined in the drum.

You have the segment/pawls/springs, and collar on the assembaly, and the shift shaft properly placed?

Are you shifting and moving the transmission gears at the same time? 

If the bike is not running, it can be deceiving on proper shifting.

Are you using a magnetic drain plug that is hitting the shift drum? 

Just asking, see if we can help...

 

 

That is kind of what I was thinking. It went together just fine with no issues. The shift shaft had to be tapped in and would not just slide in. 

I am 99% sure I have the shift pawls in there correctly. My phone is updating so I will attach a pic in a second.

I was trying to shift it by turning the countershaft with a ratchet but it just feels really bound up and the shifter is not moving. I put the chain on and tried moving the back wheel but that isn't doing anything either. I haven't tried with it running because I don't want to screw anything up. I have a brand new TMR 295 on this beast and I am trying to be gentle...Haha!

No magnetic drain plug on the bike that could be causing problems.

 

Edited November 9, 2017 by MX763

[YZDOC]

1 minute ago, MX763 said:

 

 

That is kind of what I was thinking. It went together just fine with no issues. The shift shaft had to be tapped in and would not just slide in. 

I was trying to shift it by turning the countershaft with a ratchet but it just feels really bound up and the shifter is not moving. I put the chain on and tried moving the back wheel but that isn't doing anything either. I haven't tried with it running because I don't want to screw anything up. I have a brand new TMR 295 on this beast and I am trying to be gentle...Haha!

No magnetic drain plug on the bike that could be causing problems.

Ok, There was a kid in Palmdale that brought his engine over and we split the case because it wouldn't shift either. He had placed the wrong dowel pin in the rear of the case when he pulled the cases together and that was the problem. 

If you had to tap the shifter shaft in you have case alignment issues or the shift shaft is bent and need STOP RIGHT THERE! I'm going to say the first is the issue. 

Sorry buddy, you are going to need to get back into it. 

[MX763]

2 minutes ago, 2 STOKE YZ DOC said:

Ok, There was a kid in Palmdale that brought his engine over and we split the case because it wouldn't shift either. He had placed the wrong dowel pin in the rear of the case when he pulled the cases together and that was the problem. 

If you had to tap the shifter shaft in you have case alignment issues or the shift shaft is bent and need STOP RIGHT THERE! I'm going to say the first is the issue. 

Sorry buddy, you are going to need to get back into it. 

 

Thats awesome! Thank you very much! The shift shaft is not bent so I think the case alignment might be the issue.

[Motox367]

Before you split again try hitting drive axle with mallot from countershaft sprocket side. Don't go crazy just good whack 

[Smoking 2's]

3 hours ago, Motox367 said:

Before you split again try hitting drive axle with mallot from countershaft sprocket side. Don't go crazy just good whack 

I trust two people, hear everyone! The two knows

[YZDOC]

When looking at the right side case and transmission and forks loaded, you read the forks from left to right like a book. If it's not C10-L-R then your forks are in wrong. 

For those that don't know L-R are the only two forks you can screw up as the C10 only fits one gear, as the L-R will fit eith of the two others. If L is in the middle you have it all in right.

4 hours ago, Motox367 said:

Before you split again try hitting drive axle with mallot from countershaft sprocket side. Don't go crazy just good whack 

Good idea, I didn't think of that. When I split Aecole's case and found he had put in the outer right case dowel along with the other two center case dowels (yes, it fits in one of the rear holes) and it had mushroomed because of being to long. His whole rear case was closed up nice but it was just enough to cockeye the case.