will the exhast fit

hello i got a new exhaust (full kit) in the post today but it is a little shorter than my original 1. all the parts look identical. but the muffler is about 5-6 inches shorter, it may be for a 50cc and my bike is a 125 if it does actually fit will it be ok?

 

thats not gonna be a problem at a guess, its a 4t im guessing?

 

Alright mate I've just been putting a new exhaust on me bike and as I was tightening it from the engine end I've bloody snapped the bolt and thread bit there's about 5 mm that I can grip any ideas how to get it out?

 

Drill it and re tap the thread

 

Can you get a pair of mile grips on it ?? If so tighten it up clamp it as hard as you can try using a pole on the end if not as said still and re tap

 

I could probly get some on it yea waiting on the father on law to come down 2mora with tools. What does re tap mean?

 

It means that you need to drill a 5mm hole in the remains of the bolt, then screw a 6mm tap cutter into it, to re-cut the thread for a new bolt. As I said in the other thread, get it good and hot, drown it in WD-40 then get hold of it with the mole grips and pray.

 

yeah if you can get mole grips on it that will be great, just this year ive spent 4 hours drilling and tapping exhaust studs (2 bikes, both yamaha jogs!). it totally sucks when that happens, when you put it together, use copper grease on the bolts and nuts, it will stop it happening next time you take off your exhaust (to change tyre or whatever)

 

Thanks for the advice lads tried mole grips today and even a bolt extracter but couldn't grip it properly so I didn't wanna mess it up. My cousin is coming down after work on wed to weld the nut onto the little bit of stud and try and turn it out. What are your thoughts on this? Cheers

 

The danger is that he could also weld the remaining stud into the head. See if your cousin can bring a blowlamp or butane torch to get the area around the stud good and hot before you try to undo it. If you are lucky, the cast iron head will expand more than the steel bolt and it will free off.

Obviously you need to remove any plastic panels and other stuff that might catch fire if you try this. The alternative is to remove the head and barrel and sort it out on a work bench and that's how I'd do it.

 

Like I said, drill and tap, that probably the quickest way to do it now, you might be lucky enough to weld a nut on, but the bolt will probably just snap again (i speak from experience, im a full time motorcycle mechanic)

 

Will try and weld it 1st and see how I get on, if not I think the head will have to come off. Will that not throw all my timing and that off? There is a chain aswell will that have to also come off? Sorry guys I'm new to bikes and I really appreciate all the help ;-)

 

to take your head off, you first need to turn your engine to top dead centre (TDC), take off the flywheel cover, and get a nice socket on the bolt, turn the engine clockwise till the timing marks line up, double check with your cam chain (it should have some marks on the pully) next take out your chain tensioner, its gonna have 2 bolts holding it on and will have a big spring in it, you can lock it off, but you usually need a special tool, its easier to take it off.

ive gotta go to work now, someone else finish this little guide off
merlin?

 

Thanks guys will have a look on the trusty YouTube later on and see how I get on.

 

TDC on a four stroke engine like this is easy. You will find that the camshaft sprocket has three holes in it; two are set level with the cylinder head with the cam cover off, the third is set pointing up at 90 degrees to the head. If you are at Top Dead Centre, both rockers will be loose and the valves closed. Remove the spark plug beforehand, to prevent the engine rotating away from TDC as a result of compression.

Set the engine in this position, remove the cam sprocket, unbolt the chain tensioner, rockers and camshaft (leave the sprocket on the cam chain) then remove the head bolts and head, carefully feeding the chain and cam sprocket through so that the sprocket remains in position. Temporarily tying the sprocket in place with a cable tie or a piece of string or wire is a good way to prevent it from moving while you feed it through the head and keeps the timing intact. Mark the rocker block orientation, so that you re-install it the same way, preserving the valve clearances.

Do your repair stuff on the head, replace it by feeding the chain and sprocket through, install the cam rockers, sprocket and tensioner, ensuring that the holes are in the original position, then the valve timing won't have changed. Re-check the valve clearances and Robert is your father's brother.

If you tied the sprocket off, to keep it in the right place on the cam chain, don't forget to remove it before you put the final covers on and start the bike!!

 

lads me cousin come round and welded the nut to the snapped stud, heated it up to fuck and it turned out! i was over the moon! got me new exhaust on and shes running great thanks for the advice everyone i appreciate the help!!! took it for a spin but can smell burning rubber. is this normal?

 

It may be the drive belt slipping a little bit. Does it smell more at the transmission side of the engine?

I'm glad the 'Get it hot and see if it turns out' approach worked on that stud, as I thought that it might.

 

I could not really figure out we're the smell was coming from tbh mate. What do I do to fix that? Yeah you nailed the heat thing haha your a star! Many thanks ;-)

 

it looks like the drive belt is rubbing a bit but im not sure. i noticed as i opened the crankcase that theres like a gear wheel and it seem very loose is this how its supposed to be?