Cleaning up the heads

[Track T 2411]

It's been so long since I've done any head related stuff, I've got a few questions. I can clean up the valves using a wire wheel on the bench grinder without harm, yes? They are pretty carboned up. I also have a ton of stop-leak in the coolant passages, and I need to figure out how to flush that out. Any suggestions? And, what is the best way to remove the alignment dowels?

[wingrider]

Best way I found with the the alignment dowels is to put a socket that just slips in, and then a good pair of pliers to wiggle the whole mess out. Most of the time they can be reused this way.

[ericheath]

+1 drill bit works also. New still available from Honda, cheap.

[robin1731]

I sometimes use a wire wheel in a hand held drill to clean up the seats and combustion chambers. These days I mostly use the soda blaster though. Water and pressure should clean coolant passages.

[Track T 2411]

Can I clean the valves themselves with a wire wheel? I'm sure I'm being over-cautious, but there is some abrasive action, and I don't want to damage the stem or face of the valve. The soda blaster is a great idea; I made one of the homemade siphon feed types that worked great at the shop, but the little compressor I have now won't keep up with a blow gun for more than about a minute (the next major purchase after I get this bike on the road!).

[ianstaley]

With the soda blasting today, I wouldn't even consider a wire wheel to clean off the Valves. 1) even a brass wheel will leave small marks on the valves, when you put her together you MAY note here guy's MAY induce small hot spots on the valves.

If you strip the engine down to base parts, valves should be removed and kept in the same order and position they came out, Have the valves soda blasted it wont hurt the metal but will clean all the crud off. You can do must the same with the heads too, either soda blast or vapour blast, I would use some sort of solvent in the water ways, maybe a diluted solution of soda, block up any outlets, and let is stand for a day or two. However, I ain't no metallurgist, so before whacking in soda check with some one that knows these things. I am sure that someone on here will come with a good answer to that. Hope it helps.

[Steve81GL1100]

When I cleaned up my heads, I soaked the valves in Gunk carb cleaner for a few days to soften up the deposits and then cleaned them off with ScotchBrite pads. Just do one cylinder at a time so as not to mix up which valve goes where.
Before:

After:

Happy cleaning!
Steve

[robin1731]

I have to disagree. If you are going to lap the valves and have the seats ground there is no need to keep the valves in the same location. Really even if you don't grind the seats but just lap them there is also no need to do it. When I do heads the seats are ground, valves are butted (stem end is ground flat), and valves are lapped. All this along with checking the guide to stem clearance. I have replaced valve guides in some heads.

[CYBORG]

I'm with Robin on this one

[Steve81GL1100]

OK, good to know. I only gently lapped my valves and was of the mindset that effort should be made to keep things in order. Although that only worked on the right head as the left one had been disassembled by the PO. I lapped until I was confident that the valves were making decent contact all the way around the seat. Didn't do any grinding or butting since the motor only had 17k miles on it.
Steve

[ianstaley]

Robin sounds like you have done this before. Think I might be doing this too once the engine is out, Mine has ran for nigh on 20 years so I just cant trust the valve seals (got new ones) gaskets or any of the rubber seals in and around the engine. They all need replacing just from the point of view that they have sat in one place all that time. If I might ask how did you check the valve stem to guide clearance, micrometer for the valve stem that's easy but inside the valve guide must be quite difficult, or did you just use a vernier top and bottom of the guide.

Ian

[robin1731]

Robin sounds like you have done this before. Think I might be doing this too once the engine is out, Mine has ran for nigh on 20 years so I just cant trust the valve seals (got new ones) gaskets or any of the rubber seals in and around the engine. They all need replacing just from the point of view that they have sat in one place all that time. If I might ask how did you check the valve stem to guide clearance, micrometer for the valve stem that's easy but inside the valve guide must be quite difficult, or did you just use a vernier top and bottom of the guide.

Ian

Yeah, once or twice. They do make bore gauges that measure very small holes, like valve guides.

[Oldewing]

He saw it in a movie once.......

[ianstaley]

Yeah me too, just, at 17 I was an apprentice tool maker, but TBH I have never seen that, I want one now. So what size valve guides do the GL1000 have, I can't see the point of buying a set of gauges that go out to 3" so one that encompasses our in and out valve stem guides would be great to have.

[robin1731]

Valve stem OD;
Intake; 6.58mm to 6.59mm
Exhaust; 6.55mm to 6.56mm

Valve guide ID;
Intake or exhaust; 6.60mm to 6.62mm
Service limit; 6.64mm

Valve to guide clearance;
Intake; .01mm to .04mm
Exhaust; .05mm to .07mm
Service limit;
Intake; .08mm
Exhaust; .10mm