Sport Bikes banner

1 - 15 of 15 Posts

·
Registered
Joined
·
1,168 Posts
Discussion Starter #1
I work with a guy at my station who owns a local automotive shop. I was thinking of asking him about looking into a valve adjustment for my bike. Is something like this terribly different from your average import car? I mean, our engines are fairly similar in design, no?

Would you trust a regular mechanic to do this work?
 

·
old member
Joined
·
13,079 Posts
If your bike is shim-under-bucket valves, they are different from a cage engine. If a valve clearance is out of spec, one must remove the bucket, remove the shim, mearsure it, caluclate a new shim thickness, put in the new shim, and re-measure. In addition, the cams have to be marked and removed to access the buckets and then replaced when done.

There's a reason why shops take 2-3 hours or more. :)
 

·
Registered
Joined
·
179 Posts
If you get the service manual there's no reason a regular mechanic couldn't do it. As stated, changing the valve clearance involves removing the cams, but as long as you make some reference marks on the cam chain and cams, it's not real difficult to do. You'll just need a decent micrometer to measure the shim thickness for replacements, but other then that if you take your time and use the torque settings for the various fasteners, then you should be fine.
 

·
Registered
Joined
·
2,643 Posts
Guys, the cams and crankshaft are marked from the factory. Do not use the mark and pray method as it could lead to expensive repairs. Just put your #1 cylinder on TDC and compression stroke and the cam timing marks should be visible and usualy horizontal to the top of the head. The crankshaft marks are typicaly behind some cover that has to be removed. Use the service manual as everything has to be torqued to a specified setting.
 

·
Knuckle Dragger
Joined
·
187 Posts
To answer your question, there's no reason YOU cannot do this maintenance. It would really help if you had an expeienced hand there the first time (in addition to the service manual and the proper tools). This is one of the maintenance items that is challenging enough to leave you feeling with a sense of accomplishment, yet easy enough to do in your garage. Plus, you will have a true understanding on how your engine works afterwards. It will no longer be a "noise-maker that makes me go fast", but rather a collection of well-machined parts that work together to make you go fast...and you'll understand what those parts are and how they work.

I'm sure with a little internet digging you'l be able to find a step-by-step how-to on your specific model, complete with photos and tips.:google
 

·
Registered
Joined
·
1,307 Posts
Depends on the bike also. Some are notoriously difficult while others are much easier.

My bike for example, I have to drain and remove the gas tank, remove body parts, etc. And the rear cylinder is just really hard to get at (small space, not well lit).

EX500 that I've helped a friend with, took about half the time and less prep time.

Some bikes are more difficult than others, read up on your service manual and check it out. Hopefully your bike is one of the easier ones.
 

·
Registered
Joined
·
5,451 Posts
I'm all for doing maintenance on your bike yourself, and that's why my bike is, literally, in 100+ pieces all over my living room. Like others have said, get a hold of a service manual and as long as you're reaonably competent, adjusting valves isn't terribly difficult. Assuming the R6 is like my bike, basically, you check the clearance between the valve tappet and the cam with a feeler gauge, remove the cams, remove the buckets from the valves and check the thickness of the existing shims. Based on your measurements, you replace the shims with thicker or thinner ones to regain the required clearance. Replace the cams and button the engine back up.

The only non-standard tool you'll need is a torque wrench, which your buddy probably has if you don't want to buy one yourself (decent ones go for around $200).
 

·
Habitual line-stepper
Joined
·
11,594 Posts
Yeah, any grease monkey can do this type of job. Get a service manual for your bike, he probably won't have one, and he should have no problem doing it.

I've never done one on a bike and would not hesitate for even a second to say that I feel i could do it without a problem (if i had a service manual).

And a nice craftsman torque wrench is only like 79 bucks or something. More than good enough for this type of job. The cheaper torque wrenches ($20-40) are NOT good for smaller torque settings. They do fine on larger numbers, though... like sprockets and axle nuts.
 

·
Registered
Joined
·
58 Posts
Regardless of whether the camshafts have to be removed to adjust the valves, any competent mechanic should be able to do it. Cars have camshafts too, you know.

The problem is that someone who has never worked on a bike before will take longer to do the job. Since most mechanics are paid by the job rather than their time, a first-time bike mechanic faces two choices -- rush the job, or work for less money than he's accustomed to. Either way, he would likely resent being given the job. Do you really want someone working on your bike who doesn't want to?

If you're going to pay someone to do the job, that person should be familiar with your bike, or at least bikes in general. The only qualification here seems to be that you know the guy who owns the shop.
 

·
Registered
Joined
·
2,515 Posts
all i know is that if i had a garage, the tools, and the time, i probably would have considered it myself. i just paid my shop $450 to do this on my F4i.....
 

·
Registered
Joined
·
179 Posts
Veefer97 said:
Guys, the cams and crankshaft are marked from the factory. Do not use the mark and pray method as it could lead to expensive repairs. Just put your #1 cylinder on TDC and compression stroke and the cam timing marks should be visible and usualy horizontal to the top of the head. The crankshaft marks are typicaly behind some cover that has to be removed. Use the service manual as everything has to be torqued to a specified setting.
Hitting those marks exactly can be difficult, especially if you're trying to eye-ball a reference mark that's down behind the edge of the perimeter frame of the bike. I did that the first time I adjusted my valves, and it took a lot of odd body positioning to do.

Now, I just make a mark on each cam sprocket and on the cam chain before I remove the cam journals. I pull everything apart, stick a long screwdriver through the cam chain so it doesn't fall to the bottom of the engine, and when I'm reinstalling stuff I just line up my marks. That's a lot easier than lining up the reference marks and counting the number links in the cam chain to properly line up the other cam.
 

·
Registered
Joined
·
2,643 Posts
Antimatter said:
Hitting those marks exactly can be difficult, especially if you're trying to eye-ball a reference mark that's down behind the edge of the perimeter frame of the bike. I did that the first time I adjusted my valves, and it took a lot of odd body positioning to do.

Now, I just make a mark on each cam sprocket and on the cam chain before I remove the cam journals. I pull everything apart, stick a long screwdriver through the cam chain so it doesn't fall to the bottom of the engine, and when I'm reinstalling stuff I just line up my marks. That's a lot easier than lining up the reference marks and counting the number links in the cam chain to properly line up the other cam.
And if your crank should move while you are trying to place the cams in the marked position you will not know it until you try to start the engine. Bent valves could result. Too risky in my opinion
 

·
Registered
Joined
·
5,451 Posts
Veefer97 said:
And if your crank should move while you are trying to place the cams in the marked position you will not know it until you try to start the engine. Bent valves could result. Too risky in my opinion
Naaa... you can and should turn it over very slowly by hand afterwards just to make sure everything back together correctly.
 

·
Registered
Joined
·
58 Posts
User Name said:
Naaa... you can and should turn it over very slowly by hand afterwards just to make sure everything back together correctly.
The correct procedure is to set the engine with cylinder #1 at TDC of the compression stroke prior to disassembly. Even if you're going to make your own marks, you need the factory markings as a backup in case the chain slips on the crank sprocket, which is easy to do. If that should happen, then your own marks are instantly rendered useless.

Once the engine is reassembled, then turn the crankshaft exactly two turns and verify that the marks are correctly aligned.
 
1 - 15 of 15 Posts
Top