Front mount hole snapped, what to do?

Beej

New Member
So I had a bike just about complete until I went to tighten down the front mount. As I was evenly tightening the side of the case where the hole is snapped. I was worried about this as the stud always seemed a bit crooked in there. Looks like the hole was drilled a little off. Anyhow, here is a pic of what broke. The stud will screw in above the break for about 1/4". Can this be fixed?
photo-1.jpg
 
If you just bought that motor I would get it warrantied. Some one who is an ace at welding aluminum could do a serious surgery there. That's about it . Sad, sorry to say that goose looks cooked.
 
If ya can get more threads out of it. Might drill it out deeper and retap it to a slightly larger bolt. So much vibration comes out of these motors it really needs to be mounted sure and strong with all the studs..
 
Beej,
I thought we had you on the road. That really stinks, buddy. You could be right about the stud being bent. That could certainly have caused your dilemma.
Goat Herder's advice is good. Contact your seller before you attempt any repairs. If they will warranty the motor then go that route. If not, don't buy anything else from them and you can try the idea of drilling the hole a little deeper. But, you need to know how much metal you have to work with. I just measured the hole depth on one of my engines and it appears that I could safely drill deeper by at least 1/4", maybe 3/8" but that'd be pushing your luck then. No doubt someone is going to suggest JB Weld...Forget it. You could 'glue' the broken piece back on with it but it would only be cosmetic. It will not hold a motor mount. If you opt for the deeper hole don't use that stud if it looks the least bit bent. Replace the studs with 6mm Allen head cap screws of the proper length and don't overtighten them.
Tom
 
2door, this is not my bike it is my good friends we are working on. The stud is an upgraded one and it isn't the part that is bent. the hole is actually drilled at a slight angle.
 
I'm thinking all thread through the lower case bolt hole w/washers and nuts on both sides(allthread the size fo the head of the case bolt and drill all the way through to the other side the right size) and figure a secure mount using the ends of the all thread
 
Beej,
The hole being drilled at an angle shouldn't have been responsible for the break. It appears from your photo that the mount sits well against the down tube, no gaps or rubber so I will guess it was a casting defect. This is why I suggest getting in touch with the engine supplier. Send the photo to them and ask for a replacement engine. If they are a reputable seller they should replace it because there appears to be no problem with the installation.
Tom
 
2Door, the motor sits in there real pretty. The rear mount is perfect as well, no gaps or anything. I didn't even have it tightened down yet when it snapped. It had at least 1/8 of an inc or more before the nut was even going to touch the mount. So bummed because I feel bad fro my buddy and I feel like it's my fault so I gotta try to save up to get a new motor or fix this one.
 
Beej,
Good luck. Let us know what you decide to do and how it works. I still suggest contacting the engine seller and see if they will replace it. Keep us posted.
Tom
 
We contacted the seller but he is not a big time retailer. He is a smaller outfit who buys BGF kits in bulk and re sells them locally. Motobike by Mark is the name. We will see if he comes to the table but I doubt it. If he doesn't are there places who will sell just a motor at a discounted price or are we stuck grabbing a whole kit. We went with this guy because he is local and most all dealers around won't ship to CA.
 
If you can't get it replaced, I would try to drill & tap it deeper. The way that engine is sitting in the frame looks very solid & should be fine!
 
Can't drill deeper on the right side. There are two case screws in the way... Here is a solution. I have another one I'm working on. I'll bet that after the rear mount was snug, that the front wasn't a good fit

Repair Front Mount pictures by Ron-Becker - Photobucket

The front is a good fit, in the pic the rear mount is tightened all the way down where it would be staying. The pieces that broke off where it snapped wre about the thickness of a sheet and a 1/2 of notebook paper. I could have broke it if I sneezed on it. That solution you have is pretty good if it will work. We spoke to the guy and he has no warranty but is willing to see if he can fix it or swap the case for him.
 
That's the ticket!! Good thinking Al.fish, more than one way to do things. I think a head with a top mount would solve many of our broken mount issues.
 
Too bad someone can't duplicate this idea on an HT 2 stroke. This is an early Harley design.
Tom
 

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That's the ticket!! Good thinking Al.fish, more than one way to do things. I think a head with a top mount would solve many of our broken mount issues.

To address the many broken engine mount problems lies with instillation, or should I say IMPROPER INSTILLATION. These cases were sent to me to play with. They were NOT mine...I have never broke a stud, stripped a hole or broke a mount, in 5 builds.

Too bad someone can't duplicate this idea on an HT 2 stroke. This is an early Harley design.
Tom

Why??? Not needed if properly installed. my $0.02
 
That third picture looks familiar.
Your idea is excellent for repairing a double busted front mount!
I bet it will work out to be stronger and more reliable than the factory mount, especially considering that it relieves all the lateral pressures off of the bolt holes which seem to be a common reason for failure.
 
That third picture looks familiar.
Your idea is excellent for repairing a double busted front mount!
I bet it will work out to be stronger and more reliable than the factory mount, especially considering that it relieves all the lateral pressures off of the bolt holes which seem to be a common reason for failure.

I have a photo much like that in my album. The thing was that nothing was wrong with the mounts themselves. The engine wouldn't fit on the frame perfectly and I used a piece of angle iron and bolted it to the original stud holes. Is this the one you are referring to??
 
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