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Old 06-16-2009, 09:04 AM
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BrettMavriK BrettMavriK is offline
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Join Date: Oct 2008
Location: Tampa Bay, FL
Posts: 390
Default Re: I've created a monster...leave the internal clutch spring alone!

I can't help it, but I have to reply to this thread.
You are kinda' contradicting yourself here, Jim.....

"Leave The Internal Clutch Spring Adjustment Alone!"
BUT it's okay to adjust it if:
-You have a really tight clutch because it was overtightened from the factory
-You have a slipping clutch
-You broke off the lever

In my opinion, it is the FIRST thing that should be adjusted, as all other adjustments will need to be made after this adjustment like a domino effect. By saying this, Jim, you are getting MB'ers to fear what's in there, and not mess with it. It's a spring guys, with a nut for a seat on one side that can be turned to make the spring more stiff or more soft. Most think the flower nut is where it's at as far as adjustment, and this couldn't be further from the truth. All the flower nut is supposed to do is "snug" the gear plate to the clutch pads and take up the slack. By squashing the flower nut down real tight all you are doing is stressing the clutch pads and effectively shortening the "throw" of the clutch lever. It is not meant to adjust the spring load of the clutch. The Spring Itself IS. Using the flower nut as an adjustment point is a "band-aid" adjustment.

After having prolonged clutch problems to where I even changed the friction material to carbonite, I decided to Adjust the internal clutch spring. Bingo! Fixed.
I wish I would have done it way earlier as it would've saved me a big load of time and grief.

What's the worst that can happen if anyone over adjusts the clutch spring one way or the other???
-The clutch slips and they go nowhere
-The clutch won't release and they have to readjust. If they decide to go riding with a clutch that won't release (not using common sense) brakes and a kill switch will overcome the motor.

If you're having clutch problems, the Clutch Spring Adjustment should be the First place you should look. All other adjustments fall after "The Most Important Adjustment" like you said.
I like the post Norm had done showing the guts of the clutch. It helps people to understand.

I think did a nice, helpful write up on Adjusting The Clutch after my experience
which prompted me to learn:

Happy Time Clutch Adjustment

The adjustment of the clutch on these engines is a magical ballet between a few factors:
1. Flower nut depth/tension
2. Internal Clutch Spring Tension (which actually is adjustable externally and is the most important)
3. Thickness of the clutch material
4. Pin Length

When one thing changes, everything else has to be adjusted.

The Internal Clutch Spring Tension can be adjusted by removing the clutch cable stanchion from the block, taking a 3/16" steel dowel and inserting it into the hole to find one of the four square notches on the internal spring adjustment nut inside to lock it, and spinning the motor (with the spark plug wire off) to tighten or loosen. Running the engine backwards tightens the internal spring; running the engine forward loosens it. Another problem I can see by design, is that there is nothing to "lock" this adjustment in place once the adjustment is made on the internal spring tension; meaning, it could "float" upon operation of the motor by vibration either to tighten or loosen....I bet on the latter.

Take calipers and measure the thickness of a couple of your clutch pads.
Find a measurement from a new set of pads. Are your pads "mushroomed"
and/ or deformed at all ?

Like I said, it's a ballet,
So start by tightening the internal spring a bit. (Back off the flower nut first by holding in the clutch lever to release the pressure) Remove the cable from the arm and stanchion from the block and go to work.
A good start is 1 revolution backwards to tighten the spring. I had to tighten mine by 4 revolutions, so results may vary depending on what Hong Kong Phooey decided to tighten yours at or if it loosened by vibration.
-Then snug up the flower nut not too tight, by holding in the clutch lever in after the Stanchion and cable are reinstalled.

Remember: Every Time the Flower Nut Is Adjusted , The Cable-To-Clutch Arm Set Screw Must Be Reset

And lastly, loosen the clutch actuator housing screws and notice if the pin pushes the housing out. If so, take note of the gap where it stops pushing between the actuator housing and the block. This determines that the pin is now too long and will need to be shortened just under the amount of this gap. Just make sure the actuator housing gap is parallel to the block top to bottom, left to right to determine more accurately how much the pin needs to be shortened. Just play with the three screws on the housing and go by feel. You will know when you got pin length right when there is ever so slight of and outward push from the pin to the actuator housing just before the housing snugs up to the block.

Now, if after all of this the housing doesn't push out at all, or the arm has to swing waaaaay in to operate, or doesn't operate at all. Then you have the opposite...The Pin Is Too Short, or the clutch pads have worn so thin that they are out of useable adjustment s

(watch out for that ball bearing behind the pin that likes to fall out and roll under your work bench)

Then the ballet begins between the flower nut, arm-to-cable set screw point, and feel.

I like it where the cable is set just off of where the arm starts to tighten when turned. A good tip is to leave the cable housing "adjuster screws" at the lever midway, and at the stanchion all the way in. This allows you to dial it in and fine tune it to exactly where you want. Bringing out the cable housing adjuster at the stanchion tightens the cable without having to dilly-dally with the cable set screw at the arm, and can provide a more minute ( my'noot ) (SP?) adjustment.


Not to step on toes here, but I felt it important to respond to this post.


Originally Posted by Creative Engineering View Post

I've seen a lot of posts lately regarding the adjustment of the main clutch spring.

I had one engine last year that had a REALLY tight clutch, (At the lever), due to the fact that during assembly the Chinese ran the preload nut down too tight!

I posted a thread on "how to" remedy this problem...external adjustment of the primary clutch spring dated 11/30/08

99.9% of the time; this adjustment is fine from the factory!

The spring is a high rate spring, which means that very little adjustment is needed to correct for a slipping clutch, or one that is excessively tight. 1/2 - 1 turn is usually all that is needed!

It is important that the spring rate is set correctly...and again 99.9% of the time it's right from the factory.

Norman did a good job of expanding on my original post, but this IS NOT something that should be messed with in general.

I posted this information to help out those who had clutch problems beyond the normal.

If you have broken a clutch lever or cable, it will help to loosen the tension on the spring.

If you have added a tuned pipe, or other performance may need to tighten the pre-load a bit.

Use good judgement...adjusting the tension of this spring should not be done until you have a full knowledge of the clutch assembly in these engines.

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Last edited by BrettMavriK; 06-16-2009 at 09:09 AM.
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