Topic: 400 F cam aadjuster bolt - my idle thoughts

[gregk]

I have taken the head off my 400 to heilcoil a new plug insert.  This was a motor that hadn't run in many years.  I discovered that the cam chain adjuster mechanism was seized.  I was able to free up the spring and arm  by taking the plug bolt out of the plunger mechanism and forcing the plunger which in turn made the blade move.  All is well I thought and put the motor back in the bike.  The motor started right up and was fairly quiet at an idle.  At increased rpm, i could hear a definite rattle.
I think that after 30 years, the springs on the plunger would be a little weak, so I removed the plug and forced the plunger a little farther into the arm.  I didn't move the plunger very much ( probably a few mm) .  The motor is now without the rattle at any rpm.

Why not then get a bolt the same thread size as the plug and turn down the lower end so it would fit ino the plunger hole.  This would enable me to adjust the tension on the arm with some accuracy.  A lock nut set up the same as the adjuster bolt would do.  Don't know if any oil would come out of the plug hole? 

Any thoughts?

Greg

[LoopsAndLogic]

How many miles on her?? Is the cam chain the original or was it replaced already?

If you have to be careful, if the cam chain is worn out and your tightening the chain just by sound, you run
the risk of either breaking the chain (cause its stretched too much), wearing out the bottom and upper cam sprockets very fast,(both sprockets are discontinued from Honda) or wearing out the sliders sooner than you think.

I've adjusted my cam chain with the engine idling at 1200rpm from a cold start, and applying light pressure down onto the cam chain adjuster bolt.

Worked very well

I did that and noticed some (very little) metallic rattling from the chain still. So I took the rocker cover off and noticed that the chain was tensioned properly, but the links have worn terribly!

Also, check with your tension on your cam chain that your cam does not role back and forth. That's an indication of a stretched chain or worn teeth on the sprockets.

Make sure your carbs are perfectly sync'd. An uneven carb sync will make the motor tick and rattle. It's very important!!

Your idea will work out just fine with a used or New chain, but be careful you don't tension the chain too much. Also, use a nylon washer like they use on 2-stroke oil pumps. They can withstand the temps!

Washers from hardware shops might not hold up to the high temps.

Hope this helps and keep riding

[jonbuoy]

I fitted a set of APE manual chain tensioners to my old superhawk - exactly the same set-up you are talking about though it was a nylock and a bolt.

[gregk]

The odometer indicates 10,000 miles.  When I had the head off, I took a good look at the cam chain.  I would assume at 10,000 miles, the chain would be original.  The chain or top sproket didn't show any signs of excessive wear.  
The guide and blade  did show signs of wear so I have got a new blade which I will use.  The guide wear doesn't seem that important as it is stationary.  

I'll ride it around a bit this spring and see how much noise it makes.  Don't want to be looking for some more discontinued parts just yet!

Greg

[mb3000gt]

i remember reader that racers used to tap the hole where the plug is rather than use the regular adjustment mechanism.