Topic: Oil Light came on while riding

[Tim2005]

It's rather odd, I've not known a chain to stretch much at all when new, and I've run the stock chains with higher lift cams too.  Do you have a stock tensioner arm around? I wonder if it is actually different size at that point & the aftermarket one is actually larger & hence more prone to getting damaged.

[PeWe]

A harder spring might help when adjusting it.

[Mark1976]

   A stiffer spring maybe, but this a known problem with the 400f. Your going to have to remove the tensioner spring cap and then insert a rod (some people use a long narrow screwdriver) to physically tap the adjuster rod down while the engine's running. If its as loose as the picture shows, it'll audibly become quieter. I've got at least 2 or 3 adjusters that look just like yours that came out of 400f motors. The adjuster rod becomes galled from the lock bolt and it then fails to move up or down in its bore as a result. You think its adjusted, but its not.

[jakec]

All good points. So the flattened portion of my tensioner piston/plunger (where the locking screw rests) is not galled. And whenever I adjust the tensioner I make it quiet and listen carefully for movement in the piston (just did it on my 350 last night). With this design I agree it must be necessary to either A. use the kickstart method or B. use the push on the piston method, or both.

Since this chain has 1,500 miles on it it has some slack but not a lot. When I was building the top end last weekend I did the tensioner adjustment with the valve cover off. Hard to explain, but I was able to set the tension by softly locking the piston in place and then installing the retainer that holds the top of the tensioner slipper in place. So I was able to control how much it bowed and observe the slack removed from the chain.

Going forward I will probably go with method B, pushing on the back of the piston, if I don't hear a significant movement simply by releasing the set scrw.

[jakec]

What we should really be discussing is the oil pump and how it failed the first time. I would be interested to know if anyone else has had that happen.

[newday777]

What we should really be discussing is the oil pump and how it failed the first time. I would be interested to know if anyone else has had that happen.

My thoughts are the vapor blast media.

[Tim2005]

Since this chain has 1,500 miles on it it has some slack but not a lot. When I was building the top end last weekend I did the tensioner adjustment with the valve cover off. Hard to explain, but I was able to set the tension by softly locking the piston in place and then installing the retainer that holds the top of the tensioner slipper in place. So I was able to control how much it bowed and observe the slack removed from the chain.

Adjusting it with the cover off is actually best of all. But not quite the way you are doing it. Instead, remove the slipper and undo the adjuster bolt, then push down on the end of the tensioner arm (the horse-shoe) with a long rod/screwdriver, compressing the springs. Tighten the adjuster bolt to hold the arm in place. Install the slipper and the slipper's retainer. Install cam & sprocket. Turn the motor to just past tdc with a spanner on the crank, keep pressure on that and release the adjuster bolt. The tensioner should snap tight and take all the slack out of the chain.

Pushing on the top of the piston is pretty sketchy, it can overtension the chain, damage the slipper or even damage the arm's hinge,  it should not be necessary either.

[Mark1976]

   I think its safe to say that the original pump failed due to contamination. If you have the replacement pump, tear it down and inspect it (no rotor damage), put it back together, after that it is what it is. The stock pump on a 400f doesn't make a great deal of pressure, it really doesn't need to. This bike hot and spinning at 10k isn't likely to make more than 35lbs of pressure. So as long as its clean and tight you should be fine.