Horizons Unlimited - The HUBB

Horizons Unlimited - The HUBB (https://www.horizonsunlimited.com/hubb/)
-   Yamaha Tech (https://www.horizonsunlimited.com/hubb/yamaha-tech/)
-   -   Help with removing head on 43F (https://www.horizonsunlimited.com/hubb/yamaha-tech/help-with-removing-head-43f-40934)

Pawlie 18 Feb 2009 02:41

Help with removing head on 43F
 
Hello All,

Undertaking a complete tear down to replace the fifth gear and to freshen up the top end. The head has never been disassembled. 1986 xt600 43f

I've got to the point where I need to remove the four main bolts that hold the head on. The ones inside with the copper washers underneath. I've applied quite a bit of force to them and am worried if I use more, they will break.
Is it ok to apply a bit of heat to free them up? Will this do any good? The manual says no heat as it might warp the head.

Any hard won knowledge from thoes that have already been down this road?
The acorn nuts in the next step look scary as well!!!

Many thanks,

Pawlie

MARK.F 18 Feb 2009 19:25

Sorry I can't help you with that Pawlie,but I'm interested as to how you get on because next month I'm tearing down my 43F.Maybe ask on the ADV rider "old school" forum?

olas altas 19 Feb 2009 03:03

You shouldn't have to use heat. When I did my top end rebuild (1992 XT600E) the four bolts you speak of were not that bad, at least that I can remember. Just undo one a 1/4 - 1/2 turn then go to the next, in a X pattern, until they all come loose. The acorn nuts are a bit of a pain...but you can break them loose with an open ended wrench. To torque them to spec, when putting everything back together, I had to buy some crow-foot wrenches and even with those it was a bit tricky.

Pawlie 20 Feb 2009 04:48

Unless these bolts are made of some super strength steel they are going to break if I apply more force. Sadly, breaking bolts is something I have much experience with.

Anyone else have any thoughts before I head over to ADV. rider?

Thanks,
Pawlie

odannyboy 20 Feb 2009 13:18

paulie,ive had the whole top end off my 1vj xt (belive they are the same?) and had no probs.all i can say is i belive the bolts you mention are inside under the cam cover and hold the head to the barrell? if this is correct then i cannot see how they can really be seized as all that can penetrate that area is oil, but they are steel running into alloy.it is also common that on rebuild people dont torque these up and rip the threads out of the alloy.
not being rude but you are turning them correctly ie anti clockwise if viewed from above.at the end of the day if you cant get any penetrating fluid in there and you dont want to heat it, brute force and fixing the consequences may be the only way.
ps the threads were torn on my barrel.if you need this repairing with a helicoil etc take it to a machine shop as they always do a better job than we can at home.

Pawlie 20 Feb 2009 18:13

Odannyboy,
Yea it's the four under the cam that hold the barrel/block on that are giving me fits.
I was trying to avoid the brute force approach, but it looks like that may be the only way!

Thanks for your suggestions.

Pawlie

BlackDogZulu 21 Feb 2009 20:00

Rather than brute force, use a bit of science. If what you have been doing so far is apply sheer muscle, sometimes the bits will respond to a sharp blow rather than massive torque. Get a good-fitting spanner/socket, hold it so all the slack is taken up, and give it a sharp tap with a big hammer. Not enough to break it into bits, but enough to shock it into submission.

If that's no good, heat is possible. Soak a towel in boiling water and wrap it round the part that the bolt is going into. This cannot harm any parts,and might just ease the joint apart to let you spanner it off.

Pawlie 22 Feb 2009 04:55

The head is now off. Two bolts came out no problem. One came out with much resistance and had a bunch of aluminum stuck in the threads. One broke off the head.

So a bit of thread repair will be in order.

The barrel/block came off today. Only problem was a stud that turned out instead of the nut.

Slow and steady progress.

Cheers,
Pawlie

apexTwin 4 Mar 2009 23:27

I had same problem with a stud coming out instead of the nut.

Any ideas for getting the nut off? or is it easier to get a new stud and bolt and cut/grind off existing?

Pawlie 8 Mar 2009 07:12

Hello Apextwin,

Here is a guess,

I would start by threadding two nuts with the correct thread pitch onto the opposite end of the stud. Then tighten the two firmly together. Then put a wrench on the stuck nut and one on the two nuts tightened down on one another. Turn the wrenches in opposite directions and see if the stuck nut comes loose first.

Good luck,
Pawlie


All times are GMT +1. The time now is 23:25.


vB.Sponsors