Worn valve guides

[mszilves]

Hey guys, I rebuilt my head last season, with new valve stem seals and lapped the valves.

Here is the article on the archives: http://www.fzrarchives.com/ipb/index.ph ... ntry387368

Since then, I've been trying to figure out why I'm burning a bunch of oil. So I figured it was rings...

I actually went to start taking the engine apart a couple nights ago to do the rings, and when I looked down at the intakes through the carb boots (luckily before I tore into the engine) I saw oil on 3 intake valves, and one intake valve shaft had vertical lines on it, like it was scraped, on the small section that goes into the guide. I'll get some pics up later.

So long story short, the head I recently rebuilt (which the ebay seller claimed to have low miles) seems to have bad guides. I believe the miles were low since the shims are close to stock numbers, so not much wear.

Now I had a quick look at pricing, and it's ridiculous! All new intake guides, valves and springs run around $500! But if I take a chance on another used head and rebuild that, I might run into the same problem, wasting more time.

I have a couple of questions:

1. How can you tell if the guides/valves are in good shape on a used head, or is there in fact any way to tell other than direct measurements when the head is apart?

2. If I do the guides, can I just replace the ones that look bad, or do I need to do them all?

3. Do I do just intake or exhaust as well?

[95FZR600]

Check your pm. If you need any parts let me know. You still have my #?

[modkingfzr600]

MSZ,

Indeed the price of rebuilding a head is pricey, i honestly would say it might be a good idea to take one more chance on a used head. this is the reason.....

the $500 dollars you priced for parts is only just that , parts. you will still have to drop the head off at a machine shop and have them do the rest , i would say that will run you around $500 alone. and by the rest , i mean knocking out all the old guides , installing the new ones. reaming all the guides to a perfect valve-to-guide clearance, then doing an entire valve-to-valve seat 3 angle cutting job, which is pretty much mandatory when you replace a valve guide because everything has to be re-centered. and if the seats don't have enough meat left on them, then you will also have to buy all new valve seats. now you are talking about 1200-1500 dollars for a rebuilt head. and by the way , a shop that will do the machining for cheap is not the way to go on a job like this , this job will require a shop with extensive experience with japanese inline fours. which is why all of this will cost so much.

because of the downtime and hassle , it would be best to replace all guides at once IF you are going this route.

as far as checking whether they are good or not before purchasing a head, have them take super close images of the exhaust ports and intake ports , and just use you're best judgment looking for the signs that i mentioned in the last post. you may end up with several heads laying in the garage ( which isn't a bad thing ) but you will find the right head.

try here, and on the archives and see if you can get a decent one off a member .

[megaloxana]

I agree with modking. My fzr needed new valves so I instead bought an entire motor(350 shipped) with 3k miles on it. I really dont like to buy "rebuilt" parts as you never know the quality and expertise of the work(always ask for recipts).

[mszilves]

Here are a couple of pics of what I'm talking about.

This is cylinder one, it seems only the right valve guide is worn:
http://farm4.static.flickr.com/3126/259 ... d7e8_o.jpg

This is cylinder three, once again, seems like the right valve guide only:
http://farm4.static.flickr.com/3126/259 ... d7e8_o.jpg

The other two cylinders are spotless.

Modking, thanks for your input. It looks like a low-mileage head might be the way to go... sucks since I've already spent a bunch of time in "rebuilding" this head with new valve stem seals and re-lapped the valves. I'd hate to gamble and do that again and have it turn out the same...

Does anyone know what a new head comes with? Does it include everything (valves etc.)? If I can get a deal on a brand new head, maybe that's another option. Would still be cheaper than rebuilding from the looks of it.