Refreshing the head

[bwringer]

Valve shims for $4.95 each at Cycle Recycle II:

http://www.crc2onlinecatalog.com

Look in "motor parts".

They work great, but the ones I've gotten from CRCII tend to be about .02 mm thicker than the marked size. So if you want a 2.55 for example, it's likely to actually measure 2.57. Kinda like an OEM "x" shim (the OEM shims marked with an "x", like "2.60x" measure slightly large).

Not a big deal, but it's something to be aware of. And, of course, YMMV. The batch they send you may measure dead on.

It's always a good idea to order extras. If you think you need 2.55, you might want to order a 2.50 and maybe a 2.60 too. Sometimes feeler gauges aren't as precise as we'd like them to be. And sometimes you just don't feel right leaving the clearance right on the edge at .04 mm.

[graham harron]

just finished mine

I just finished mine as i am in the process of a winter build on my gs750l
I have installed the Wisco 814 cc Big bore kit. The main reason i took the engine apart in the first place was my valve seals were bad,The number 4 plug would get oil on it just sitting in the head !!! I was shocked to see the amount of CRAP on the intake valve stems i am sure the motor will breath much beter after the cleanup, I changed my valve seals without using a spring compressor But i do not reccomend this,I just pushed down on top of the keeper with a pair of linesman pliers and fished out the keepers,I hand lapped the valves lightly even though i here suzuki says this is a no no, but ill take my chances on that one. install is easy like has been said before just oil up the seals and install by hand just make sure you have them on all the way as there is a ring that holds them onto the guide.

[RJ]

Yeah sorry to agree with the other guys but if you want to eliminate the smoke you're going to have to pull the head to replace the valve seals. Of course once you do that it would be silly not to replace the guides, as well as lap the valves. Of course since you have everything apart you might as well get a nice 3, 4 or 5 angle valve job done, etc, new pistons, etc..........My bike does the exact same thing. I'm going to leave it alone for a while and let things break a little more before I tear into anything. Spend your time riding (and enjoying) the bike and restore it only when everything is broken............. Too bad I can't follow my own advice!

[Jethro]

After some fiddleing with the head off my 81, and taking out a few of the valves, I'm gonna settle for a simple valve clearance adjustment this year on the 83. The bike has killer compression, runs great and only has 16000 on the motor. Why mess with it.

The weather better break soon so I can ride, or I'm gonna get stupid with the tools !

[duaneage]

usually the seals are rotted and need replacing, you'll need to check end-play (wobble) on the valve stems to determine if the guides need replacing or not, you'll need a dial guage and some kind of fixture to hold the guage to check this...

Hold your finger over the valve guide hold and pull the valve out about 1/2 inch and let go. A good valve guide will pull the valve back in with vacuum, bad ones don't.

[daveo]

Hold your finger over the valve guide hold and pull the valve out about 1/2 inch and let go. A good valve guide will pull the valve back in with vacuum, bad ones don't.

Good tip ...Thanks

[Anonymous]

Hi Jethro,

If the bike has such low milage, the seals will have hardened but the guides should be still OK. With the compression holding up well and being so even across all cylinders your rings also sound OK - as do your valves themselves.

Smoking a little on startup is sometimes caused by standing the bike on the sidestand instead of the centrestand. When tilted like that the oil around exhaust valve #1 can't flow down into the sump, but stays in the well around the valve seal. When you start the motor a little is sucked down the stem.

If you are burning oil when running it could be the hardened seals letting you down, or there might be some crankcase pressure helping it past the rings. Check that the crankcase vent between the valve cover and the airbox is clear.

If you decide to replace the seals you will be up for, at the very least, the seals (get the real Suzuki bits and not cheap replacements) and a head gasket (not cheap but these days multi-layer metal instead of asbestos sandwich type) and a valve cover gasket (they tear easily when removed) and new crush washers for the headers.

Then there is the time to get it done (save it up for winter). You can do it without taking the motor out of the frame - thank you Mr Suzuki, many bikes can't do this.

The valves can be put back in the same positions without cutting fresh seats. If there is a buildup of carbon under the exhaust valves (sometimes happens) you need to clean it up. Then the valve seat should be done and new shims will be needed. Suzuki specifically says not to lap these valves with paste - make your own choice here.

This is a lot of work/money for the sake of some smoke on startup and oil use when running. An alternative is to add some oil stuff to stop the smoke, the oil usage is hard to avoid if the seals have hardened. Having someone drive behind you to check smoke while running under different conditions can tell you a bit of what the engine is doing as well.

Most of all, enjoy the ride while the weather lasts. The northern hemisphere has ways of keeping bike riders indoors.

Kim

[lhanscom]

Get a head gasket, and valve seals, and a valve spring compressor. If you're just doing the seals it will take you a weekend to do, assuming you don't find anything funky. If you have a bunch of clean up to do it will take a bit longer, all depends on how far you want to go.

[Jethro]

I got the same spring compressor from Sears as you have, Luke. Modified with a small piece of pipe like you suggested and it works great. I messed around with the head from my 81 last night. That head has over 20k miles on it and it seems fine. I'm just gonna do the clearances and ride the sucker. Next year I'll rip it apart.

[Hoomgar]

After some fiddleing with the head off my 81, and taking out a few of the valves, I'm gonna settle for a simple valve clearance adjustment this year on the 83. The bike has killer compression, runs great and only has 16000 on the motor. Why mess with it.

The weather better break soon so I can ride, or I'm gonna get stupid with the tools !

Rock on Jethro! After reading what Keith said and realizing the reality of that being right and the state of the engines compression you described I was hoping this is what you would do.

They get dirty, if it isn't complaining, ride it!

[Anonymous]

It was me that started the cold start smoke thread and I think im going to just ride the bike for a while and see what happens because it just seems to be going so well it seems a waste of time pulling it apart and like its been said earlier it might not stop at just seals once you start working on the engine
Ride it and see what happens
Trev