Yamaha 130 V4 Project Build.

Interesting, cause that crack looks like it is ready to run around the back. Sucks to get bumped into but it was good to get your eyes attention back there.

Had a similar thing two weeks ago, customer bringing his race car up to prep for raing the July 4th weekend. The Monday night before the owner stops for gas an hour from my place. A young guy filling his M3 at the station just looking over at the EVO on the trailer says to the owner, "Thats quite a crack in the brake rotor" Light was just right for him to see it.
Sucked for us since both front rotors were cracked and at $900 each were not available in country.

Im much less concerned about having it pretty than strong so we are really going to beef this up.I think some big plates on the outside could be made to look like they belong and Im also wondering about relieving it after its welded. Cryo? Bake it? Then have Dago square it up on the CNC and surface it.
Im even thinking about some cross bracing side to side like a big X inside the mid if it can be done around the tuner. Tuner is pretty small so there shoudl be room. That would tie the top of one side to the bottom of the other and really strengthen it.

Drill holes at the ends of the crack , do that before welding . If you cant see the end well remove the paint and use a little heat it will help find the end .

Marty can solve that no problem.

I went for a RIDE today... You dont know how lucky you are to catch it BEFORE its a problem :thumbsup:

When you say you went for a ride....I hope it wasnt a wet one???

So no question about the crack. I have it all torn down already and ready to send to Marty. Ill send him this one and a virgin mid in case he would rather start from scratch. The crack did grow a little on the ride back from the spring to the ramp (12 miles). It wasnt into the pocket for the lower mount and now it is.

Pulled the powerhead by myself with no hoist. :D

Attachment 301897

Welded castings are when not if.

I see a fair bit of bubbles along that weld. What does it look like from the inside?

If this were to be repaired I would add a diamond shaped doubler from the upper section with formed edges along the lower such that the doubler is not flat against the lower at the step. Did I word that right?

The existing porosity in that weld might render a repair difficult, which obviously you know since you are sending along a virgin mid as well.

Cryo,
The metallurgist I work with states that Cryo treatments basically work with tool steel and is a marketing gimmick on most other alloys and materials. Might just be his company's opinion.

Quote:

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Originally Posted by CharlieN

I see a fair bit of bubbles along that weld. What does it look like from the inside?

If this were to be repaired I would add a diamond shaped doubler from the upper section with formed edges along the lower such that the doubler is not flat against the lower at the step. Did I word that right?

The existing porosity in that weld might render a repair difficult, which obviously you know since you are sending along a virgin mid as well.

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Thats why Im sending him a virgin mid as well. Like I said earlier, that crack had already been welded once. The original welds that Kottman did look beautiful.

Any thoughts on this? When I pulled the powerhead yesterday I had two broken studs. Yamaha has 6 long bolts (3 each side) that run up through the adapter, two short bolts at the back, and two studs in the front. Both studs were broken. I have had this powerhead on and off a couple times and never had an issue. The adapter had just been surfaced to its flat. No other issues with the other bolts, just the studs.

I've seen them broke if the PH doesn't come straight up off the adapter...lifting from the stock lift eye pulls up on the back and if you go too far it can break the studs or pull them out through the front. Maybe they've been tweaked in the past and just gave up..

Some of The bolts loosened up. Doesn't take long to break after that. I'll look for pics of the one that broke on me.

Quote:

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Originally Posted by DoktorC

I've seen them broke if the PH doesn't come straight up off the adapter...lifting from the stock lift eye pulls up on the back and if you go too far it can break the studs or pull them out through the front. Maybe they've been tweaked in the past and just gave up..

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I bought a few 8mm eyebolts from McMaster that I screw into the flywheel that gives me a good point to lift from.

Ran 104mph in 2 pieces :eek:

http://i408.photobucket.com/albums/p...8/P6090164.jpg
http://i408.photobucket.com/albums/p...8/P6090167.jpg

I bet you didn't make a second run?