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How to guide: Adjusting your valves 101 with pics and vid

199K views 168 replies 93 participants last post by  bry  
#1 ·
Here’s another tutorial for those looking to save some money by adjusting their own valves.

Notice: This valve adjustment procedure was performed on a 2002 Suzuki Volusia with naked jugs (i.e. de-paired and de-filtered). Having a pair valve and/or air cleaner installed will require the removal of additional parts.

For this procedure, we need the following tools:

17mm, 10mm and a 8mm ratcheting box wrench (5/8” box wrench for Mustang seat)
3/8” socket wrench, 10mm socket, 12” extension
Phillips and slot screwdriver (size 2)
Suzuki spark plug socket (from toolkit)
Set of metric Allen wrenches
Needle nose pliers
Set of security bits from Harbor Freight (will explain later)
Feeler gauges (optional)
Spark plug gap tool (for gapping spark plugs)
Wire brush (for cleaning spark plugs)

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The #10 security bit from this Harbor Freight set comes in handy for holding the valve adjustment screw in place.

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The motorcycle must be completely cold before you can accurately adjust the valves (wait 24 hours after ridding it). Secure the motorcycle to a stand or jack at a comfortable working height.

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Remove the seat using a 6mm Allen wrench. Mustang seats require a 5/8” box wrench. Use a 3/8" socket wrench and a 12mm socket to remove the bolt holding the gast tank to the frame.

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Using a 3mm and 4mm Allen wrench, detach the speedometer housing from the gas tank. Slip back the boot on the wire harness underneath and squeeze the plug so it releases from the speedometer assembly.

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Detach the vacuum hose, fuel line and idle adjustment from the left side of the gas tank using the needle nose pliers; position an old towel to catch the fuel from the hose.

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With the handlebars straight, carefully lift up the back of the tank (near the seat) and disconnect the fuel gauge sensor plug. Then, carefully remove the fuel tank from the frame. Sit the fuel tank aside on a soft surface to prevent damage to the underside.

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Remove the plastic neck covers from both sides to expose additional working area around the valves.

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Loosen the hose clamp securing the carburetor to the intake using a Phillips screwdriver. Carefully lift up the carburetor off while rocking it back and forth. Put a towel under the carburetor to catch any excess fuel.

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Using an 8mm ratcheting box wrench, remove the chrome sparkplug covers from both sides of the bike. Then, use the Suzuki spark plug socket and a 17mm ratcheting wrench to remove the spark plugs from the engine.

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You are ready to remove the valve covers. I usually start with the harder to reach bolts because they are prone to falling. Using an 8mm ratcheting box wrench, slowly remove the hard to reach bolts on the rear right and front left covers.

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Remove the 10mm nuts from the top of the bike using a 3/8” socket wrench, 10mm socket and 12” extension.

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Remove the remaining bolts using a 8mm ratcheting box wrench. Be careful not to drop the bolts into hard to reach places.

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Using a 10mm and 8mm Allen wrench, remove the caps from the engine covers. The large cover is where we will be rotating the engine with a socket wrench; the small cover is a viewing hole to align the RT/FT marks (more on this later).

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Using a 3/8” socket wrench, 17mm socket and 12” extension, slowly rotate the engine counter clockwise. The valves will begin to move up and down on both cylinders. Be aware, you should NEVER rotate the engine clockwise as it may cause damage to the engine!

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While slowly rotating the engine, use a flashlight to look into the viewing hole. Every full rotation of the engine, you will see an R/T and F/T mark pass by. These marks help you locate the adjustment positions for either the Front (F/T) or Rear (R/T) cylinders. These positions are also called Top Dead Center (TDC).

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Continue rotating the engine. Take notice to the valves on top of the rear cylinder. They will open and close in the following pattern:

Exhaust – open (down)
Exhaust – close (up)
Intake – open (down)
Intake – close (up)

Here’s a video showing the above pattern:
http://s1225.photobucket.com/albums....com/albums/ee393/OregonLAN/Volusia Riders/?action=view&current=valve_video.mp4

As soon as the intake valves on the rear cylinder close (as shown at the end of the video), use a flashlight to look for the R/T in the viewing hole. Slowly rotate the engine until the R/T mark is dead center in the viewing hole. This is the adjustment point for the rear cylinder. If you accidentally bypass the mark, you will have to rotate the engine around a couple times until the valves open and close again.

Finding the adjustment points on the front valves is done in a similar manner. Rotate the engine counter clockwise until both the exhaust and intake valves on the front cylinder have opened and closed. Use a flashlight and slowly rotate the engine until the F/T mark is dead center in the viewing hole.

Work on one cylinder at a time. Use a 10mm ratcheting box wrench to loosen the retention nuts around the valve adjustment screws. Loosen the valve adjustment screws using the #10 security bit until they can be rotated by hand.

You can adjust the valves using either a feeler gauge or the “Jpaige” method. A feeler gauge is arguably the most accurate method, but it’s also the most difficult method.

The specification for the exhaust and intake are as followed:
Exhaust - .007 - .009
Intake - .003 - .005

Insert the feeler gauge between valve adjustment screw and the lifter as shown. You will have to bend the tip of the feeler gauge to get an accurate adjustment on all the lifters.

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The “Jpaige” method doesn’t require a feeler gauge. It’s based off a mathematical calculation of the screw’s thread pitch. You simply finger tighten the valve screw until it touches the valve lifter. Then, you back out the exhaust screw 1/4 turn (90 degrees) and the intake screw 1/8 turn (45 degrees).

Adjust and secure each valve individually. Use the #10 security bit tool to hold the valve adjustment screw in place while you tighten the retention nut with a 10mm ratcheting box wrench.

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Assemble your bike in reverse order. If everything is adjusted properly, you should hear a very faint ticking noise at idle (commonly associated with a sewing machine). Improperly adjusted valves will result in excessive ticking noise, poor performance and overheating.

While everything is accessible, now is a good time to clean off or replace your sparkplugs and check the gap. Use a wire brush to clean off the soot and the gapping tool to adjust them as followed:
0.8 – 0.9mm (0.031 – 0.035 in)
 
#134 ·
Completed this procedure today(my second try at it). Thanks for the awesome directions. I do have one question though. How can I make sure the engine isn't 180 degrees out? I waited until the exhaust valve closed and then turned to the adjustment marks. Is this ok? First time I tried I couldn't move the exhaust valves and I'm guessing they were still open. ?

Sent from Motorcycle.com Free App
 
#138 ·
The ''generic'' torque chart says that the 6mm bolt/nut spec is 88 in/lb.

I realize that you can't get a socket and torque wrench into the tight space with the engine still in the frame so I tried it using my Snap-on in/lb. torque wrench on the engine I have sitting in the corner of my shop.....

That works out to 1/2 flat of rotation from a finger tight position on the adjuster screw/locknut.....

Realistically, it is difficult to tighten that locknut much more than that in that tight location anyway but now we know.... Thanks for asking!!! :wayhappy:
 
#139 · (Edited)
Just finished the expletive inducing task of adjusting the valves on my "new" 2005 C50. :curse:

I had a mechanic do it, but the bike came back with lose of power, tappet noise, and the floor boards feeling like a foot massager from Brookstone. So, I thought I'd tackle it myself to see if the mechanic did a bad job. Turned out all but two of the valves were opened beyond the 5 and 9 thou limit. I could see why, it's a pain to do accurately.

After messing with the feeler gauge set for way too long, I got smart and pulled 3-5 and 7-9 thou and bent them, the tab on the business end being about 3/8 - 7/16 from the tip. I used a long skinny screw driver to nudge them into the gap. The bends also made it convenient to hang them on the handlebar for easy access. I also made a tool to hold the adjuster screws, using a couple square drive screws and scrap piece of hardwood, gluing the screws in place so they would not spin. One screw positioned with the flats parallel, and one diagonal.

These two tricks made the job much easier and precise. It was a lot of extra work, but I figured this would not be the last time I do the adjustment. Hope this helps other weekend mechanics like me.
 

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#140 ·
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#141 ·
Well I'm involved in this job right now. I've had this for five years and since I've owned it the valves have never been adjusted. I started noticing some tapping on acceleration more so when it's cold so I figured I would look into it. I'm a little puzzled though the intake valves are snug at .003 and the exhaust valves are snug at .007 so I'm reluctant to even loose them. Has anybody else experienced this?
 
#142 ·
It isn't what "fits snug".

It is "what goes and what doesn't go". If a 4 doesn't and a 2 does - you know it's a 3. If a 3 goes and a 5 doesn't - it's a 4.

"Snug" is a very relative term and especially in the tight quarters on the C50.
 
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#146 ·
Add me to the long list of folks that did it myself because of the confidence inspired by this thread. The key for me was to purchase some inexpensive 8" long feeler gages and bend them with (2) 90 degree steps so they just slip in between the top of the valve and the adjusting screw bottom. Made the job a lot easier. Since I purchased el cheapo gages, I mic'd each one and wrote down it's actual thickness.

All valves had little to no clearance. Bike had 4500 miles on it w/o any work on it before (except oil changes). Will be much easier next time.

Thanks again to all that supplied their tips and tricks, and the OP that took the time to document this PITA job.

And yes, the valve noise did increase, but not a whole lot as I adjusted them closer to the minimum than the maximum clearance.
 
#147 ·
Absolutely fantastic ! It is years later, but you picked my Volusia (2004 Carburated) to do this tutorial on. Rather than a newer injected bike. Pictures are the bomb ! I plan on doing a valve adjustment, and was in process of buying a shop manual. This is SO much better lol.

Don't know if you still hang out on this Forum, but no matter, Thanks for a great well done step by step !
Marty
 
#149 ·
I need some help guys. Please forgive me in advance if this has been answered. I truly tried to search for an answer before posting here.

I have a 2013 C90T Boss and I am attempting to do a valve adjustment. The bike is in the garage and I have followed the service manual to get everything removed/prepared. But, I am having some problems. The one I need help with is finding either the "R|T" mark or the "F|T" mark. The only "marks" I see as I turn the crankshaft is two grooves (lines if you like). Both grooves (lines) are at separate locations, and, one is wider than the other. But, that is the only two things I can see. There are no RT or FT markings. So, am I correct in assuming that one of the grooves (lines) I see (when looking inside the access hole) is the "RT" (rear top dead center line for the rear cylinder) and the other is the "FT" (front top dead center for the front cylinder). If so which one is for RT and which one is for FT?

Thanks in advance... if I had any hair I would be pulling it out right now. :)
 
#150 ·
Welcome to the VR.


If you truly have a C90, then you have hydraulic valve lifters and NO ADJUSTMENT IS NEEDED.....

See the spec description in the picture.....
 

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#151 ·
As I stated, I have a 2013 Suzuki Boulevard "C90T" BOSS. I also have the "Service Manual" for it and it has the procedure for "adjusting the valves". I guess you'll just have to believe me. Is it possible that because mine is a "Canadian" model, that the specs are different? Or, is the service manual I have a complete fabrication? I find that hard to believe since there are multiple pictures showing many locations that are EXACTLY like the bike I have.
 
#152 ·
Here is a quote from the Service Manual...


Valve Clearance Inspection And Adjustment

Inspect valve Clearance
Every 24000 km (14500 miles, 48 months) thereafter


Valve clearance adjustment must be checked and
adjusted, a) at the time of periodic inspection...


The manual then goes on to show how to do it. I followed all the instruction (using) the diagrams that look EXACTLY like the parts on my bike. What's going on?
 
#153 ·
Sorry, My mistake. We haven't dealt with many of the new c90's here and you are right.

The new c90's apparently use the water cooled M90 engines that do have the valve adjustmet. The older vl1500/c90's are hydraulic "adjusters"


There has to be an "r/t -f/t" mark on that flywheel somewhere.

The other way to find the adjustment location for crankshaft position is to watch the valves.

>>>As you rotate the engine, Notice when the exhaust valve on the cylinder is closing. When the exhaust valve is ALMOST CLOSED, watch for the line on the flywheel to come into the inspection window. Then turn the crankshaft 1 complete rotation (360 deg) back to the same line. That will put you on TDC of the compression stroke.

Watch the exhaust valve for the second cylinder to get it in the correct position in the same way.

The manuals do specify "the compression stroke" but they don't tell you how to determine if you are on the compression stroke and since the mark will line up in two different stroke positions - (also TDC exhaust stroke) you could adjust incorrectly and have way too much clearance when you are done.

I hope this helps you out....
 
#154 ·
Thank goodness. I thought I was loosing my mind!!!

There is definitely no RT or FT markings as I look into the inspection opening... just 2 lines that are located quite a fair bit apart as you rotate the crankshaft... one slightly wider than the other. Also, there are four "cylinder head inspection covers" (2 for each cylinder). When removed, you gain access to the adjusting screw/lock nut/rocker arm/valve stem. The problem is I can't see the valves moving up/down. Can I put something in the spark plug holes (like a straw) and use that to determine valve movement. If so, can you give me a tip on how that would work?
 
#155 ·
They sure don't make valve adjustment access easy do they.



All the straw will do is confirm piston location and the flywheel mark position.

You will still need to ensure that you are on the compression stroke TDC.

That can also be done by holding your finger over/in the sparkplug hole while rotating the engine. You will feel the pressure build under your finger as the piston comes up in the cylinder on the compression stroke.

The spark plug location might be too deep to reach with a finger though.. so something like a compression tester adapter might work better.... a piece of fuel hose or similar that seals at the plug hole and you can still feel the pressure...

Some even use a small balloon on the end of the "hose" that will fill as the piston comes up....

Once you "feel" the pressure, use the straw to indicate when to expect the TDC line for that cylinder lining up with the inspection hole.
 
#158 ·
About 4800 km from you... Dartmouth, NS. :)

I just took a look at the manual for the 200th time. Although it mentions RT and FT, I "think" I know which "line" is the RT and which is the FT. Here is my logic...

In the manual, it states that after finding RT and completing the valve adjustments on the rear cylinder, rotate the crankshaft counterclockwise 486 degrees (or 1-1/3 turn) and lineup with the FT line and perform the front cylinder valve adjustments.

So, I think that I found the RT line (the "thinner" line of the two). Here is why I think that. I put 2 straws in the rear cylinder spark plug holes. When I move the crank shaft to that line, the 2 straws both move up all the way. And, when I then move the crank shaft 486 degress (1-1/3 turns) the second "thicker" line comes into view. What do you think?
 
#159 ·
Well, I went ahead and adjusted the rear cylinder valves only. They seem to have been "tight" (a 0.003 feeler would barely fit), so I adjusted them to a "tight" 0.005. I put the bike back together and it runs fine.

As a side benefit, I checked the gap of all four spark plugs that I had installed recently. They were all too tight. The bike actually runs much "smoother" (less vibration) now.

Thanks for the help!

Murray
 
#160 ·
WARNING!!!

Please make sure...


If you have a 2013 or later C90 (like me), and you attempt to do a valve check/adjustment, make absolutely sure that you CAREFULLY tighten down the valve adjustment access panels. I took my bike out for a ride this morning, only to have engine oil come pouring out and all over me and my bike. Luckily, there is a motorcycle shop close to home (where I was) and I took it there. Since they have to take everything apart to get at the panel I did not tighten down, I'll pay them to do the valve check while they're at it!

I will stick to oil changes and simple stuff like that from now on! Have a good riding season my friends, and please, Ride Safe!
 
#161 ·
Photo Bucket Rip off?

So this great work that OregonLan did so long ago is all for not because photobucket decided to hold third party hosting hostage? Is it just me or can nobody else see the pics in the sticky any more? As I understand it, photobucket now charges $400 bucks a year if you want to see the pics that were used and hosted by them.
It looks like OregonLAN's post is probably the best valve adjustment pictorial out there (and I've searched) but I cant see a !@#$%^&*!!! thing! I'm about to do my first valve adjustment on my 2002 Volusia and it sure would've been nice to have all the greats pics with the tutorial. Think it will ever be reposted with pics again/available?
 
#169 ·
Want to say thanks again. Used this thread years ago. And here I am again 10 yrs later and it's still useful.
I'll add, I didn't have a security bit set, but I did and a Philips head screw that fits almost perfectly over the square tappit. Left one long to reach in from the top and cut one short for reaching under. Added a couple of nuts for grips.
147621
147622
 
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