ok, I've made a lot of progress at this and I'm almost there. I've removed everything including the cams and shims/buckets from the head and removed the 8 cap nuts and the single bolt that hold the head to the block. My problem is that the head is stuck tight; I cannot lift it off and the manuel specifically says not to use a pry-bar. I've hit all around the mating area with a rubber mallet, it didn't help. Is there something I'm missing? Why won't it come off?
Also, on the front side of the head there is a sensor or switch mounted with a thick cable running up to instrument cluster. The Haynes manuel doesn't mention anything about this part in the head removal procedure. I'm thinking it's maybe the speedo or tach sensor and it will obviously have to be removed. What is this part and how do I remove it?
Thanks a ton, this is a great learning process...
-M
Whatever you do, don't take hardened steel anywhere near the aluminum head -- steel will win every time. Your idea of hitting it with a rubber mallet is a good one -- try every angle and just per persistent. If you really have all the fasteners off, it should work loose by repeated hits in a twisting angle.
I've never done that job, but know how stubborn a gasket with a lot of surface area can be. Maybe someone else has some advice that's sure fire?
ok, it turns out the switch/cable is the tachometer sensor, which makes sense. There's a nasty oil leak around the unit so I'll have to clean that up and check out the gasket.
Still no luck with the head, I put it up for the night and I'll try again tomorrow. Maybe heating the area would help?
-M
I used a 2x4 piece of wood about a foot long. Find the line between the cylinder and the head and place the 2x4 against the bottom head fin as squarly as possible and hit it upwards with a fairly light hammer on the bottom end of the 2x4 alternating sides of engine and hitting harder till it breaks loose. Only hit as hard as necessary to break it loose, they look ugly with broken fins.
thx for the tip, I'll try that tomorrow :cheers:
-M
here's a crazy idea... what do you guys think about laying a long dowel (broom handle?) in place of each camshaft, bolting it down with the cam caps and lifting the ends of each dowel with automotive jacks? The direct vertical force should pop the head right off right? On the other hand, the head is aluminum and if those cap bolt threads strip out I'd have a big problem. Maybe this isn't such a great idea...
-M
NNNNNNOOOOOOOOOOOOoooooo!
The last thing you want to is suspend the weight of the engine by the precision machined bearing surfaces of the cam holders!
On the front and back of the engine between the cylinders there are two spots where head overlaps the cylinder. With a LARGE flat blade screwdriver or (preferably) an aluminum or brass rod, tap up against it gently with a ball peen (not a rubber mallet). This should break the adhesion of the head gasket.
Don't strike the corners of the cooling fins even with a rubber mallet. The head has locating pins that prevent diagonal or twisting motion. All you will do is risk busting the fins.
hehe, ok I'll forget about that last idea. Thanks for the advice James
Ok, I was finally able to get the head off yesterday. It took some gentle persuasion with a crowbar (fyi don't ever apply pressure to the sealing faces, just between the fins where they're reinforced) and I managed to break off a small piece of cooling fin :mad: No big deal though.
As soon as I can borrow/make a valve spring compressor I'll get those valves out and clean everything up real nice. Hopefully nothing will need to be replaced.
-M
you can borrow one from discount/advanced auto for free... use it backwards and a big socket and you can do that.... or just build the one with a clamp and a piece of piping... good luck... its an easy job... I did it very recently... if you need some help just ask
Austin
I asked a bike-mechanic friend of a friend how he deals with stuck cylinder heads. The answer was simple and according to him it never fails. It sounds drastic but after thinking about it I cant see what real harm it would do.........Crack the head bolts then re-do them finger tight, then lift the plug leads and blip the start button. The compression will free the head from the cylinder. Hhhhmmmm :icon_confused:
wouldn't that trick pressure spray oil all over the place? It's an interesting idea, maybe as a last resort...
-M
Quote from: Mandres on March 25, 2006, 04:29:05 PM
wouldn't that trick pressure spray oil all over the place? It's an interesting idea, maybe as a last resort...
-M
Probably not. You might get a little splatter, but if the bolts are finger tight, it shouldn't be that bad I wouldn't think. If I ever have to take off the head, I'll probably give it a try if it's stuck.
By the way, the valve guide came today. Thanks again. I couldn't get anything that would bond the plastic. It must be polyethylene, polypropylene, or other polyolefin. There's not much that'll bond them that you can find at the local hardware store....
even then, your not cranking hell outa it, your just bumping the starter. would work ok IF there are no bent valves to let out compression.
Ok, I've got the whole top end stripped to the crank. In my typical ham-fisted fashion I managed to break two of the piston rings trying to remove them. Replacements are on the way :mad:
With some awesome assistance from Dgyver I managed to remove all 4 valves tonight too. One of the intake valves is noticeably bent. I have no idea how it happened but I bet it's the root cause of my problems. The valve seats and guides in the head seem to be ok, but I'm not really sure how to properly evaluate them. The good straight intake valve slides smoothly and seats solidly in both of the cylinders, and the bent valve hangs up in both. I'm planning to order a replacement for the bent valve and then re-lap the faces and seats on all 4 valves as described in the manual.
Unfortunately my digi-cam is broken or I would have some good pics to share. I'm going to try to borrow one tomorrow.
-M
Upon further cleaning/inspection the valve guide for the bent intake valve is cracked. That's going to have to be replaced too. I'm starting to think I would have been better off just buying a complete head off of e-bay. I've already got > $100 into replacement parts for this engine. It'd better start up once everything is reinstalled, otherwise I'm going to just light a match :2guns:
-M