APE JAY - Question on APE timming components

I have a 1980 650 I am rebuilding and I replaced all of the stock cam chain idlers with APE gears, this engine has a roler timming chain, not the HI-VO type. I have a problem with the top idler assembly, the one that its on top the head between the cams. The APE part sits too high and I can't bolt it down, the stock assembly will bolt up just fine. The timming is correct and the chain is new, and indexed correctly on the cams. I have new mounting blocks for the top idler. I just can't get it to fit. Any suggestions?

"The APE part sits too high and I can't bolt it down, the stock assembly will bolt up just fine. "

For my KZ900, the mounting blocks were tight getting into the base of the idler assembly, use some lube, wd40, silicon spray etc... One of the mounting pieces has stubs that slide through the idler base holes.... Insure that is correct...

Not sure if you were meaning sits too tall and valve cover hits the idler so.... probably not due to "can't bolt it down so just checking....

Questions...

In measuring the top idler heights... are they the same or is the APE idler actually taller?

If above proves they're the same, try using your original mounting block, does the APE idler now work?

Your doing all this with the timing chain adjuster out of the motor correct, thus the chain has slack?

OMR

This is an engine I have just finished putting together, there is no tensioner installed and the chain, idlers, tensioner roller assembly, and bottom roller (the rubber one) have all been replaced.

I am referring to part no. 12057-001HP

kzzone.com/sprockets.html

I'll tkae a picture at lunch. That should clear things up.

I'm afraid the top idler assembly you bought from APE is not the correct part - Ape no. 12057-001HP replaces OEM no. 12053-1035 which is used on these models:

KZ1000-A3 (1979)
KZ1000-A3A (1979)
KZ1000-A4 (1980)
KZ1000-B3 (1979)
KZ1000-B4 (1980)
KZ1000-D3 (1980)
KZ1000-E1 (1979)
KZ1000-E2 (1980)

The pre-81 (single roller cam chain) 650s use part no. 12053-1012 or 12053-1013 - not exactly sure about the difference between the two but I'm pretty sure they'll interchange.

However, the sprockets in the 12057-001 and the 12053-1012/12053-1013 are the same - if the 12057-001 has a removable sprocket like the 650 assy you should be able to swap the new sprocket/bushing into your old stock bracket and be good.

I was just going to say, I didn't think that part fit a 650. We do have the sprockets separately.

Jay

I replaced the tensioner and both idlers and they worked out just fine. I just assumed this part would work as well. My bad. I think I can install the sprocket in the old mount.

APE did a great job on this stuff, these parts really beef up the timming system, I would HIGHLY reccomend these parts as the timming chain seems to be one of the more common failure points in these engines. The rubber roller in the stock tensioner had broken and the chain and gears were pretty beat up on this motor when I got it. Thats twice I have seen problems in a timming chain and this is only the second 650 engine I have had apart.

Here was the result of adding the APE sprocke tto the factory mount, took a bit of doing but it should work just fine.