Chipped engine block. JB weld?

[kenken2812]

Well last weekend I took an unfortunate spill, going about 45. My frame slider broke off as well as my crankcase cover. The stator was destroyed, as well as the generator. While removing the remains of the crank cover I found that a small chunk on the bottom of my engine block missing. My friend suggested JB weld, not sure if this would work or even if a professional welder could do anything about it. I would greatly appreciate any and all input.. Even if it means the block is done for. Thanks ahead of time, ill post more pictures as soon as I can

 

[FinalImpact]

^^ Welcome to the 4'uhm and I must say that's a very unfortunate way to join the board, but Glad to have you just the same.

Also, Glad you're OK and want to fix er up! :thumbup::thumbup:


Structurally, not much goin on there. However, the high volume of oil being slung in that direction could take JB out sooner than expected and the chunk if set free into circulation could do lasting damage and even cause another crash.

I would opt for welding. The downside is the area has to have the oil baked out to TIG weld it. Most would likely heat the area so this could be headed towards a complete tear down.

IIWY, i'd print some really good picture of several areas or take the bike to a machine shop that welds aluminum heads and ask them their opinion. Perhaps you could get away with stripping the parts off the crank and having it welded or maybe drop the engine from the chassis and hand that to them. I'd guess they'd charge less if they can move it about, weld up the busted bolt hole and tap it - restore threads.

Lets see what other have to say and start looking for a welder!

 

[Nelly]

As Randy has already said :welcome:, glad your ok.
I have no experience of using JB weld so I can't comment on its suitability for this purpose.
I have used epoxy resin to fix a large crack in a petrol tank seem without any issues.
If your bike was my bike I would look at a more permanent fix and go for welding as long as it was cost effective.

Nelly:thumbup:

 

[kenken2812]

Damn. That's what I was afraid of. I feel like this is going to be quite a bit more pricey than i had hoped. Thanks for the advice!

 

[Yasko]

Do you think you would have been better off without the frame sliders?

Do I need to get rid of mine?

 

[kenken2812]

Do you think you would have been better off without the frame sliders?

Do I need to get rid of mine?

No no, definitely keep your frame sliders they are made to protect the engine, mine I guess may have been to long or just crappy sliders so unfortunately they broke before the could be of any real help. Invest in some carbon fiber ones, or even get a frame cage for protection

 

[TownsendsFJR1300]

I know you were working on removing the damaged Rotor Assembly off the crank. Once that's out of the way, check to make sure the end of the crank isn't bent. If its bent, its a parts motor.

If you can shoot a picture from the front of the engine, it's hard to tell how deep the chip is. Your actually fortunate its not adjacent to a bearing/load bearing.

+1 on welding the block in either case (no pun intended).

With the rotor out of the way, there should be plenty of room to weld a bead (DISCONNECT THE BATTERY) and another atop the first if necessary, until you reach the gasket surface. With the fuel tank removed(safety/nothing to leak), the welder should be able to lean the bike over on the right side plenty to lay a bead on the left case.

Covering everything under that cover both when welding and then taking a die grinder to clean up excess new weld is a must..


As a side note, on my first Yamaha 125cc, 2 stroke, the PO busted the block where one of four long cylinder/head studs screw into(holds the cylinder and head to the block). What was left of the hole was wallowed out, part of the corner of the block was actually missing. I did pull the engine, head and cylinder. Cases NEVER GOT SPLIT. My dad brought the engine to a welder who filled in the aluminum hole and then some. After days of filing (I didn't have any air tools, this is about 1972, I was about 16), drilling and tapping by myself, the engine was done. I did have the crank stuffed with rags before any filing but still flushed out the lower end (again a 2 stroke with a closed/sealed bottom end).

Point being, any good aluminum welder can lay a bead after cleaning it up, some grinding, etc. We did those repairs all the time when I worked in a machine shop years ago. I didn't weld aluminum (everything else), but to do the clean up grinding, etc . Be prepared to get a dremel and some nice flat files. A little bit of Yamabond (centercase sealer) not normally used on the cover would be a good idea to use on both sides of the gasket when you get that far...

 

[kenken2812]

Well it sounds like it's totally doable. Kinda sucks because I live on a military base in a barracks so I don't exactly have a garage or space to do most of this in. Hopefully ill be able to figure something out. I really don't want to have to part her out or have to get rid of her. D,:

 

[chroline]

so which frame sliders did you have? so we can avoid them

 

[kenken2812]

so which frame sliders did you have? so we can avoid them

not sure what brand or what exactly they where, but its a very hard plastic-ish material. not entirely sure what to call it. they came with the bike (i bought it used so that probably doesn't help) :/ in the picture you can see where it broke off, i believe it may have been too long and fell at the wrong angle and it wasn't able to support the weight of the bike.

 

[kenken2812]

here are some more pictures of the block

 

[TownsendsFJR1300]

Once that assembly (and large starter gear) is off the left side of the engine,
shouldn't be difficult to weld up.

Several thin passes with a TIG welder after a good cleaning should take care of it..

 

[FZ09Bandit]

Well it sounds like it's totally doable. Kinda sucks because I live on a military base in a barracks so I don't exactly have a garage or space to do most of this in. Hopefully ill be able to figure something out. I really don't want to have to part her out or have to get rid of her. D,:

Does your base have a garage that you can take it to, work on, and even store it? Ft bliss did when I was stationed in El Paso.

Jb weld is good for somethings, but I wouldn't recommend using it there. It will do fine until you're far from home.

 

[skooter65]

I wanted to extend an offer that I had suggested to another member (Didn't work out in that case). I have a motor from an 07' that I have begun to part out and can give you a heck of a deal for the complete lower assembly if you are at all interested.

Good luck and Hopefully you can get back on the road soon enough!

 

[TownsendsFJR1300]

I wanted to extend an offer that I had suggested to another member (Didn't work out in that case). I have a motor from an 07' that I have begun to part out and can give you a heck of a deal for the complete lower assembly if you are at all interested.

Good luck and Hopefully you can get back on the road soon enough!

The generator (yes, the heavy round part that spins) is destroyed as well, I've been PMing him re checking the crank as it could very well be bent..

 

[FinalImpact]

The generator (yes, the heavy round part that spins) is destroyed as well, I've been PMing him re checking the crank as it could very well be bent..

^^ That took a pretty good blow!
Looks like the TIP over sensor was on the ball as the engine didn't have much rotational momentum when it hit whatever did that. WOW!

Like Scott is hinting at, I'd magneto off and inspect the crank for run out.

In short you need:
A dial indicator to measure lateral run out on the cranks end (rent for cheap).
A puller to remove the damaged magneto magnet.
Remove the spark plugs so it turns easily by hand.

Obviously a magnetic base dial indicator won't work but one with a tab of stiff sheet metal attached to an adjacent bolt. Then set the pointer on the cranks end and zero the dial. Rotate crank in 90 degree increments. Yes, Yamaha FSM calls it a "generator".

The runout limit may be hard to measure while dragging the pistons up and down the bore. Squirt some oil in them to reduce friction as the measurement is so small.

Runout Spec: 0.030 mm (0.0012 in)

A couple of sample pictures:

With external mount for base and V blocks:

Checking end play: incase it damaged the thrust surface.

Above you have to move the crank in and out while reading the dial.

 

[kenken2812]

Does your base have a garage that you can take it to, work on, and even store it? Ft bliss did when I was stationed in El Paso.

Jb weld is good for somethings, but I wouldn't recommend using it there. It will do fine until you're far from home.

Unfortunately to Autoport on base is total garbage. They don't even have useable tools :/ and yea that's a good point about the JB weld. A quick cheap solution is rarely a permanent one.

 

[Marthy]

Here's are my tough... whatever that worth. Welding aluminum is a b^%$!!! It pull and deform a lot. Might end up with a bigger problem. I agree with some that it's not structural and other than leaking... the bike should still be fine. Still look at the crank, not a lot of leverage there but worth double checking. Most than likely you will see it right away when you replace the housing... if it wobble.

As for the repair... your call. Personally your bike is a 07 with xxx mileage. I would bang it back together and fix it the best I could with JB welder to contain the leak. If you let it cure properly that thing will last for a while... probably longer that you will own the bike. If it last... leave it like that. If it cause you issue then you have time to either get a new ride or buy a use engine and just replace the whole thing. If it was a 2012 I would suggest different but if your bike is a high mileage 07... I would just patch it and run it as is until it last.

I'm not saying it's the best option, just the better option considering the investment-repair vs. the value of the bike.

 

[kenken2812]

Sounds like I'm gonna have to pull the engine if I'd want to check out the specs on the crank.. That oughta be interesting. As of now I'm having a hell of a time trying to remove the generator, I've tried two different pullers and it won't budge. And skooter if you could pm me the details we can discuss it!

 

[kenken2812]

Here's are my tough... whatever that worth. Welding aluminum is a b^%$!!! It pull and deform a lot. Might end up with a bigger problem. I agree with some that it's not structural and other than leaking... the bike should still be fine. Still look at the crank, not a lot of leverage there but worth double checking. Most than likely you will see it right away when you replace the housing... if it wobble.

As for the repair... your call. Personally your bike is a 07 with xxx mileage. I would bang it back together and fix it the best I could with JB welder to contain the leak. If you let it cure properly that thing will last for a while... probably longer that you will own the bike. If it last... leave it like that. If it cause you issue then you have time to either get a new ride or buy a use engine and just replace the whole thing. If it was a 2012 I would suggest different but if your bike is a high mileage 07... I would just patch it and run it as is until it last.

I'm not saying it's the best option, just the better option considering the investment-repair vs. the value of the bike.

You are right on that. I definitely won't have the bike forever. I'm just skeptical of the overall durability of the JB weld and if the oil will erode it or cause it to break apart then there is a chunk flying around in my engine. Lots of possibilities. Just gotta make a decision I suppose. Question though, once I get the new stator and generator installed and if I were to bolt on the case, would the engine start at that point? Even with the hole on the block?