# Cracked block



## Ken692 (Feb 15, 2013)

Is it gone, or can it be salvaged, 
Conecting rod hit it?
Is it a bad idea to jb it.


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## Kiss4aFrog (Nov 3, 2013)

Is it a dual shaft engine. If it is that's a good reason to try and save it. Single ... not so much.

You can try to degrease it, sand the inside and outside some to roughen the surface up a bit for a good bite and then JB Weld it and you'd likely be good but there are so many cheap snow blowers out there it seems you could buy a repairable pretty cheap for the engine. If it's not a twin shaft, MY machine, I'd replace it.

Where are you located ?? Please add your location to your profile. It can make a difference on what options are available and you never know what someone might find for you on craigslist or have sitting in a corner and offer you if you're close.


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## caddydaddy (Dec 10, 2014)

I'd also suggest to JB Weld it.


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## 43128 (Feb 14, 2014)

if its not a twin shaft head down to harbor freight and buy a predator.

25%off coupon-21741290


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## Shryp (Jan 1, 2011)

JB Weld might work. Some people have done that. Some people have also had the blocks tig welded. There is also a product called aluminium brazing rod that is basically a stick of solder that you put on with a propane torch.


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## Ken692 (Feb 15, 2013)

I'm in Boston its a single shaft w/o pto
On closer inspection the crank race got smoked I did find a nice used short block but I hate to just trash it


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## GustoGuy (Nov 19, 2012)

Ken692 said:


> I'm in Boston its a single shaft w/o pto
> On closer inspection the crank race got smoked I did find a nice used short block but I hate to just trash it


Since it is a single shaft engine why not replace it with a Predator 212cc engine.


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## 43128 (Feb 14, 2014)

its junk get the predator, the piston and cylinder are also probably destroyed as well as the crank


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## Kiss4aFrog (Nov 3, 2013)

If the journal on the crank is gouged it's scrap metal. Might want to save the carb and whatever you think might come in handy that you have room for but it's time for a different engine, sorry.


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## 94EG8 (Feb 13, 2014)

That block is very salvageable, I've fixed much worse. The crank probably is too. They always look terrible, but I haven't seen one yet that was actually scored, the aluminum from the rod just transfers to the crank journal and makes them look that way. Clean it up with some fine emery cloth and chances are it'll come out just fine. Tap the block back into place, clean the paint off with a wire wheel and then some brake clean, apply JB Weld and put it back together.


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## Ken692 (Feb 15, 2013)

94EG8 said:


> That block is very salvageable, I've fixed much worse. The crank probably is too. They always look terrible, but I haven't seen one yet that was actually scored, the aluminum from the rod just transfers to the crank journal and makes them look that way. Clean it up with some fine emery cloth and chances are it'll come out just fine. Tap the block back into place, clean the paint off with a wire wheel and then some brake clean, apply JB Weld and put it back together.


Yes it looks like exactly that, aluminum from the rod. I guess there is no pressure on the sump side.
Funny that everyone recommended getting the chonda (lol) HF motor. As that's what I had said to him, next I knew he had done just that and gave me the damaged motor. This is all new to me and have to say I get great info here and hope others find it helpful. I did find a great deal on used short block and I'm in the process of moving parts over. Still not sure why one engine had a 1" output shaft and the other has 3/4". but all the parts seem to fit fine, the flywheel sits within just 1/8 below the threads on the crank 
This is the good block, too bad my 10000 needs the pto this turned out to be a nice motor total invested so far $70


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## Ken692 (Feb 15, 2013)

Here is a shot of the crank


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## 94EG8 (Feb 13, 2014)

Ken692 said:


> Funny that everyone recommended getting the chonda (lol) HF motor. As that's what I had said to him, next I knew he had done just that and gave me the damaged motor.


It's pretty hard to beat those Honda clones, especially for the price. They're definitely a better engine than the old Tecumehs ever were. But that said you can fix a Tecumseh awfully cheap if you do it the way I said.



Ken692 said:


> This is all new to me and have to say I get great info here and hope others find it helpful. I did find a great deal on used short block and I'm in the process of moving parts over. Still not sure why one engine had a 1" output shaft and the other has 3/4". but all the parts seem to fit fine, the flywheel sits within just 1/8 below the threads on the crank


The cranks are different based on what the OEM that was buying the engines wanted for whatever equipment they were were going on. There were a few different variants.

Also, the cylinder looks to be worn and scored in the old block, so while you can certainly fix it as I said, it's probably going to burn oil.


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## Ken692 (Feb 15, 2013)

So this is great experience working with this 7hp, (fits nothing I have)
I get to do a dry run on this, 
Getting up the nerve to fix my beloved 22000.
Image 2 is a better look at the 7's combustion chamber, I am getting conflicting info on honing out the the bore. Some say not to its bad some say just run the tool in and out easy as that. And back yard guy said just use some emery paper? What is the easy and inexpensive way that works


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## 94EG8 (Feb 13, 2014)

Run your fingernail against those vertical scratches, can you feel them? If so it at the very least needs a hone, if they're deep enough it needs an over-sized piston and rings (which if I remember correctly are no longer available)

The cheapest/easiest way to do this is to get a cheap hone that uses sandpaper, put some 320 grit aluminum oxide paper on it. Then coat the cylinder with oil and hone it using an electric drill moving quickly up and down the cylinder bore.

Most of the time the original style rings for those older Tecumehs are no longer available so you'll instead end up with a new style piston along with a set of rings and a wrist pin. The last time I bought one they were about $30.

I'm guessing you've never assembled an engine before, when you do it put motor oil on the crank journal before you attach the rod to it, do the same for the wrist pin, cam and coat the cylinder before installing the piston. Also make sure the ring gaps don't line up, stagger them.


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## HillnGullyRider (Feb 9, 2014)

Use the Muggy weld brazing rod...its a 20000psi repair


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## Ken692 (Feb 15, 2013)

Just scored a nice spring compressor 
I must be crazy


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## RedOctobyr (Mar 2, 2014)

Not that crazy. I had to compress the springs on a flathead Tecumseh to reinstall a valve. I didn't have a proper compressor, so I had to rig something up with a few flathead screwdrivers, a clamp, and I don't even remember what else  It worked, finally, but it was way harder than it should have been. 

I was definitely wishing for a real spring compressor! Good score.


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## Ken692 (Feb 15, 2013)

Now I have my eye on the flywheel holder. I'll use it once in my life, but it's such a pain without the tool.
Guess that's why they made them.


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## 94EG8 (Feb 13, 2014)

Ken692 said:


> Just scored a nice spring compressor
> I must be crazy


What's the part number on that spring compressor?



Ken692 said:


> Now I have my eye on the flywheel holder. I'll use it once in my life, but it's such a pain without the tool.
> Guess that's why they made them.


If you use an impact gun it's totally unnecessary.


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## RedOctobyr (Mar 2, 2014)

94EG8 said:


> If you use an impact gun it's totally unnecessary.


Yup. I've removed a few flywheel nuts with my impact gun, it's super-easy. 

If you don't have a compressor, there are also electric impact guns. I bought my Harbor Freight electric one before I got a compressor, I've been very happy with it. My pneumatic one is smaller and lighter, but the electric one is very convenient. 

Admittedly, the impact gun doesn't help for re-torquing the nut after, but I didn't have any trouble doing that with a torque wrench.


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## 94EG8 (Feb 13, 2014)

RedOctobyr said:


> Admittedly, the impact gun doesn't help for re-torquing the nut after, but I didn't have any trouble doing that with a torque wrench.


No one torques them in the real world. Just put them back on with an impact.


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## Kiss4aFrog (Nov 3, 2013)

B&S Valve spring compressor #19063

https://www.rcpw.com/briggs-stratto...TtdCVf7rE1p_zUE6hkcH704m3M7lk8-o8sxoCTurw_wcB


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## classiccat (Mar 1, 2014)

94EG8 said:


> No one torques them in the real world. Just put them back on with an impact.


One word of caution using an impact: crankshafts will break if over tightened.

I personally use a torque wrench with a strap-wrench around the flywheel.


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## Ken692 (Feb 15, 2013)

94EG8 said:


> Ken692 said:
> 
> 
> > Just scored a nice spring compressor
> ...


19063
Not sure impact to take the bolts of but the spring is a bit hard to put back on, not sure how an numatic would help


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## Ken692 (Feb 15, 2013)

Kiss4aFrog said:


> B&S Valve spring compressor #19063
> 
> https://www.rcpw.com/briggs-stratto...TtdCVf7rE1p_zUE6hkcH704m3M7lk8-o8sxoCTurw_wcB


Wow $26 I paid $30 wtf you guys are unbelievable, correct parts at the best prices, ok that flywheel holder is $32
And there are three or four Different ones I have the Tecumseh 4 and 5 hp


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## 94EG8 (Feb 13, 2014)

classiccat said:


> One word of caution using an impact: crankshafts will break if over tightened.


Common sense goes a long way. I've never broken a crank yet doing them this way, and I've done a lot of them. 



Ken692 said:


> 19063
> Not sure impact to take the bolts of but the spring is a bit hard to put back on, not sure how an numatic would help


An impact gun wont help you a bit doing valve springs, we're talking about removing flywheels.


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## classiccat (Mar 1, 2014)

94EG8 said:


> Common sense goes a long way. I've never broken a crank yet doing them this way, and I've done a lot of them..


Yep, don't doubt that one bit! You always give great advice.

I'm assuming that the OP has not done alot of them; my advice to someone new to wrenching on SE's is to use a torque wrench. Not enough and you risk shearing the flywheel key. Too much & you have a busted crank.


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## RedOctobyr (Mar 2, 2014)

Or you can split the flywheel, as I understand it, if it's a tapered fit. 

I've only done 2. So I definitely used a torque wrench


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## Ken692 (Feb 15, 2013)

I picked up the HF torque wench 3/8"and a 1/2" they were $9 it's showing 150fp but I also have an older beam type that shows 600fp I'm guessing the 4hp needs around 400 foot pounds on the fly nut 
I'll try to find the torque specs
Didn't get to check the valves today, I did get the gas out of her though. I picked up a small craftsman 5-21
But the c-lister stiffed me and it had a huge hole in the block, did have a brand new carb so I did get a few parts off it.


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## RedOctobyr (Mar 2, 2014)

400 ft-lb??? 

The Tecumseh Technician's Manual for the L-head engines lists about 40 ft-lb, depending on the engine model. 

Please double-check the torque before cranking it to 400 ft-lb. I think that is much much too high.


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## Ken692 (Feb 15, 2013)

Not sure it's a hs40


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## Ken692 (Feb 15, 2013)

This is the service manual
HS 400-500 
Am I seeing this correctly?


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## Ken692 (Feb 15, 2013)

Yes I'm getting over 400
Ok I'm seeing inch and foot 
I'm lost


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## Kiss4aFrog (Nov 3, 2013)

If it's 400 it's inch pounds.

That really big nut on the front wheel drive axles normally are 100 to 200 lbft.
That little piece of threaded crankshaft would break before you get to 100 lbft IMHO.


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## classiccat (Mar 1, 2014)

Ken692 said:


> Yes I'm getting over 400
> Ok I'm seeing inch and foot
> I'm lost


the torque values listed in each row are equivalent; inch-pounds are foot-pounds multiplied by 12 (_since there are 12" in a foot_). For example, 480 in-lbs = 40 ft-lbs.


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## Ken692 (Feb 15, 2013)

I guess the 600 flb bar torque wrench will be good for the head bolts, 
It was cheap only $14, glad I left off at adjusting the points and putting the flywheel back on!


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## RedOctobyr (Mar 2, 2014)

Ken692 said:


> I guess the 600 flb bar torque wrench will be good for the head bolts,
> It was cheap only $14, glad I left off at adjusting the points and putting the flywheel back on!


The cylinder head bolts are listed as only 200 in-lb, 16.5 ft-lb  There is really nothing on the engine that needs (or is well-suited to) a 600 ft-lb wrench. 

Generally, I'd suggest using the smallest torque wrench that still goes up to the torque you need. They'll be more accurate when you're using a significant percentage of the total rating. 

If you need 30 ft-lb, and you're using a 600 ft-lb wrench, that's only 5% of the total range. It's unlikely to be very accurate at that low value. 

But if you have another 150 ft-lb wrench, for instance, then the 30 ft-lb is 20% of the total range. Still not ideal, perhaps, but at least better. 

I have a 75 ft-lb beam-style torque wrench. I use it for most things, it's a nice intermediate size. Less convenient than the click-type (I need to be able to see the needle during use), but also more accurate, and much less likely to be affected by being dropped, etc. 

I also have a 150 ft-lb click-type, but I only use it if I need >75 ft-lb.


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## Ken692 (Feb 15, 2013)

Got this I always over buy


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## Ken692 (Feb 15, 2013)

Sorry for all the lame questions, this is more difficult than I ever imagined. Yet still simple enough that I feel like I know what I'm doing, I have repaired a few, ramble my question is at one point I put the flywheel on tight, I didn't have a torque wrench but may have tried to guess 400. Nothing broke but did it stretch out the aluminum??
And if I torque to 40 is it going to hold fine?


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## RedOctobyr (Mar 2, 2014)

If you torque it to what the manual says for your engine, it will hold fine. 

If it was me, I'd probably loosen the flywheel nut, and re-torque it properly. But I don't have a good feel for 400 in-lb. As someone mentioned, some people probably never use a torque wrench for these. But they may do a lot of them. For those of us without experience (me), using a torque wrench seemed like a much better idea. 

If the nut is too tight, it's possible to damage things, though it might have happened right away. 

But if it's too loose, there will be too little friction between the crankshaft and flywheel. This can allow the flywheel to spin on the crankshaft, shearing the soft flywheel key. This will mess up your ignition timing, potentially making the engine no longer run at all, or at least making it run worse.


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## 94EG8 (Feb 13, 2014)

If there's going to be any damage from over tightening it will be immediate, and for what it's worth you'd have to have severely overtightened it to have any damage. Basically if you cranked the nut on well beyond what the torque specs are you have 3 possible modes of failure:


Nut or threaded end of the crankshaft strips (this is probably the most likely scenario)
End of the crank breaks off. (unlikely, but possible)
flywheel crack and splits (I can't see this ever happening, 1 or 2 is almost certainly going to happen before this point)
You'd likely have to more than double the torque value to get to a point where something is going to happen though.


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## Shryp (Jan 1, 2011)

It would probably be pretty unlikely, but I bet there is a chance to put a small crack in the flywheel that isn't noticed. Afterwards you could start up the engine and the crack could cause the flywheel to shatter. That is probably the worst case and highly unlikely.

For torque wrenches, Harbor Freight often has theirs on sale for under $10 for each size. Also, Autozone will let you borrow theirs for a $100 deposit, though you get a refund if you return it within 90 days.


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