Hi I need some advice. Bought an old monster 600 at Christmas. I have great dreams and aspersions for it to turn in to my dream cafe racer. I have thrown money on tools and mods. The bike was working well when i bought it but bad surface corrosion on the engine. I have stripped it down and got the engine out to service, soda blast and paint. My issue is I can get the front downpipe out the head. I tried for days with the engine in the bike. I decided to cut the exhuast halfway down near the oil filter, leaving enough room to play with. It still won't budge. Tried heat every night and soak in penetrating oil but i fear I my damage the head if i try to hard. Thing seems rusted in there. Feel like just sending it to a garage. Has any anyone got any advise. Before any one asks I have another set of exhuast to go back on. Plus I have remove the rusted nuts. (Job in itself). Just want think bugger out. Thanks.
Sound like the exhaust collets have rusted up, assuming you’ve removed the clamp, you might need brute force...
A blowtorch or preferably oxy-acetylene to get a decent amount of heat into the remaining exhaust followed by dousing with penetrating oil ought to do it.
Hi Chris. I have had a blow tourch on it every night (3 night) i heat the pipe up at the nearest point I can near the head and try to hit it with a heavy rubber mallet I soak it in pb penetrating oil. And leave it until the next night. Getting me down now.
If you have enough pipe to get a a grip on drill a hole straight through and through the pipe. Pilot drill and open up to a bar size, pass bar through pipe. Soak the head area with plus gas,other penetrating oils are available. Wiggle waggle the header out using the bar. You can also apply heat to the header at the same time whilst wiggle waggling. Freeze spray also works on the header which ideally you want to shrink not exspand. Aluminium melts at 850 ish centigrade keep a gas axe well away from it. Other ideas are available
you do need to really "cook" it.. is it the std stainless exhaust? You need to introduce the heat through the remaining exhaust, not the cylinder head casting. You will know you've got it hot enough as you won't be able to see it for smoke when you douse it, although deceptive in this cold weather.
Heat first, freeze spray is just an option, heat up cool down the object is to break the bond expand and contract. Too much heat around the head can cause problems. If you have a bar through the pipe 8/10 mm a little bit of rotation can help.
Hi I had to all your advice but sadly no go. I even called a couple of local motorbike garages. One said they wouldn't touch it and another said next month when they were not busy. (Yea alright). Anyway I cut it with the angle grinder as close to the head as possible. The used a dremel to painstakingly cut it out piece by piece. Took 6 hours. It seems there is some sealant put in with the exhuast that is almost as strong as the metals as i have 1 inch piece that still would budge . Is this possible or do you think i needed a better blow tourch?
Well done, no, I think you probably took the right approach. If the the 2 half-sleeves had expanded massively with corrosion then it’s possible no amount of heat would have allowed them to shed much of the mass that had expanded.
