I noticed this the other day while doing my pre-start check. I pulled the bolt out and it appears it broke off somewhere inside the actual engine block. I have not done anything with it. Any tips on how I should proceed or what I should do?
How do I fix a broken motor mount?
- Thread starter Ron-P
- Start date
if your lucky there might be a part of the stud still sticking out that you can grip with vice grip pliers to remove the broken stud. Or you will need to remove the broken stud by drilling into it and removing it with an easy out. If you can find left handed drills sometimes the broken stud will come out as you drill it.
What I meant is that it appears to be broken off right at the point where the motor housing meets up with the bracket that holds the motor to the frame.
Thanks Norman, I'll remove the other bolt and pull the bracket out and see where the bolt snapped off. Hopefully you are right and there's enough bolt sticking out for easy removal. If not, I'm sure I could find a left-handed bit online (great suggestion by the way, thanks).
I know that harbor freights sells left hand bits in a set I have their set but haven't used them yet so I don't know if they are very good I also have a set of snap on left hand bits which I know work.
you might even be able to use a dremel cut off disc to cut a slot in the offending stud then unscrew it I know removing a broken stud can be a pain.
you might even be able to use a dremel cut off disc to cut a slot in the offending stud then unscrew it I know removing a broken stud can be a pain.
Ok Norm, see if you can help me, rode my bike to work the other day on the way, 2 different times, it just kinda lost all it's power n eventually just killed @ wot! However, each time it did, it started right back up n away i went? After sitting for a couple hrs, decided to take it for a lil spin, no luck! The thing just won't fire, but it has spark, fuel, and compression! So wtf?
Do you know how much gap is on the spark plug? I run a 0.020 gap.
What in the ratio of your fuel to oil? I run about 1/2 gal through the engine at around 20 to 1 then go to either 32 to 1 or a 40 to 1 with syn oil.
Is your air filter still clean?
are your wiring connections all tight including your spark plug leads.
and is your spark plug oily looking or dry and tan? when looking at the electrodes of the spark plug.
Just some ideas for you to look at.
What in the ratio of your fuel to oil? I run about 1/2 gal through the engine at around 20 to 1 then go to either 32 to 1 or a 40 to 1 with syn oil.
Is your air filter still clean?
are your wiring connections all tight including your spark plug leads.
and is your spark plug oily looking or dry and tan? when looking at the electrodes of the spark plug.
Just some ideas for you to look at.
Back to the original question of a broken bolt. I had this happen as well. I couldn't get an easy out to work so I had to drill and tap which was kind of a pain. Afterwards I read other posts and hindsight...If you have something to grab on to with pliers then great if not, I might suggest to use a dremmel. Cut a slot in the top of the screw to fit a flat head driver and see if you can unscrew it. Us some PB blaster or such to wick into the threads and loosen it up.
Worse case, it can be drilled and tapped if necessary but I think it could open a can of worms for someone who is not familiar with tapping.
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I should add when tapping threads in aluminum you need to use a cutting fluid made for aluminum one is kerosene. Or buy a cutting fluid that is made just for aluminum it will help prevent the tap from sticking and breaking the tap. If you break a tap off in the hole its a real bad day trying to remove a broken off tap. There is special tools sold for removing broken off taps but they are hard to find and expensive to buy.
The Rubber used allowed the motor to oscillate or resonate at a different frequency than the clamp used. This is what broke the stud. Typically engine studs are screwed in all the way down and some what tight. Looks like yours is broken off flush with the motor. Not sure since the pic is with the motor still installed. But it looks like it is a flush break. This will be tough to remove and very very time consuming. You need to drill and Ez it out with an EZ. Pull motor, take motor to Hardware Store and show them. They will get you the drill bit and EZ out that you need. Since your stud is most likely down all the way and tight, it will be a tough job. But you may get lucky and it will come right out. Heck, there may even be enough protruding out where you can get a vice grip on the stud and unscrew it. That would be a dream come true if that happens. At any rate, once you get it removed, reinstall motor and make sure to remove that rubber stuff. These engines require a ridgid solid install to the frame so that this will not happen again. I am surprised you only broke one stud using this mounting method. Using Rubber is not good and not needed in MHO. Thanks. Enjoy the ride.. 
Thanks for the tips guys. I'll take it apart next week and see what I'm up against.
I bought this bike with the motor already mounted to the frame so I figured the rubber was normal, I'll remove it when I do the repair. I've never tapped a bolt before so I'm hoping this won't have to be my first time.
I bought this bike with the motor already mounted to the frame so I figured the rubber was normal, I'll remove it when I do the repair. I've never tapped a bolt before so I'm hoping this won't have to be my first time.
Tried the Dremmel trick, finally. No luck, ended up cutting into the engine block a bit, not too bad though.
So, I got a "Gripper" at Lowe's, basically the same as a Easy Out. Hopefully I can try this in the next few days.
If that does not work I'm just going to find a different way of mounting the engine block to the rear seat post and bypass the current mounting system. As long as it's secure it should be an issue no matter how it's mounted.
So, I got a "Gripper" at Lowe's, basically the same as a Easy Out. Hopefully I can try this in the next few days.
If that does not work I'm just going to find a different way of mounting the engine block to the rear seat post and bypass the current mounting system. As long as it's secure it should be an issue no matter how it's mounted.
No luck, engine is now out and headed to a friends house, he's an engine mechanic and says he can get it out, if not looks like a new engine block is in order.
Good tip - an improvement on that I've done more than I care to remember is to place a nut over the broken stud and fill it with the welder - then jus' use a wrench to pull out the "bolt" you jus' made
My buddy got the bolt out, I'm now in the process of re-installing the engine. Hopefully I'll be back up and running tonight.
Took her for a spin around the block a few time tonight. She lives!!!
Still have a lot of tweaking to do, and rebolt everything with some threadlock. I was having some trouble keeping her running, I'd throttle up to about 20 mph and then she'd sputter down to idle, or die. After close inspection I found a melted wire that was up against the exhaust pipe. Hopefully that's the problem. I'll dig deeper into it tomorrow.
Still have a lot of tweaking to do, and rebolt everything with some threadlock. I was having some trouble keeping her running, I'd throttle up to about 20 mph and then she'd sputter down to idle, or die. After close inspection I found a melted wire that was up against the exhaust pipe. Hopefully that's the problem. I'll dig deeper into it tomorrow.
Ron,
Here is the posts of what the gys told me to do when I broke mine. The tool I bought to remove the bolt worked great. Good luck with yours. I hope all works out and will expect to hear updates.
http://motorbicycling.com/f4/broken-motor-mount-stud-13776.html
Here is the posts of what the gys told me to do when I broke mine. The tool I bought to remove the bolt worked great. Good luck with yours. I hope all works out and will expect to hear updates.
http://motorbicycling.com/f4/broken-motor-mount-stud-13776.html
Thanks for that link Sharksfan. Per my last post, the bike is now up and running, just need some tweaks to get her back to peek performance.