what does the decompression pin look like?

and how do you know if its whats causeing the knocking sounds im hearing?

Pin seen next to black mark..

auto_decomp3.jpg

Actually that is the operating pin. The pin that contacts the valve lifter is the cross pin that, that pin is pressed into. About 1/2" above the black mark on the left.

The point of failure that I have seen is that small pin will break off or fall out. Then the cross pin just free wheels and contacts the valve lifter randomly.

Mine looked like this. It was found on the magnet of my drainplug.

img5612m.jpg

FYI, finding it was the only sign of a failure. I heard no out-of-the-ordinary engine noise.

ok is it the pin right beside the black mark on the right or the thicker looking pin on the left just above the black mark?

ok is it the pin right beside the black mark on the right or the thicker looking pin on the left just above the black mark?

The small pin on the right of the black mark is the decompressor cross pin .. which controls the movement of the pin on the above left of the black mark..

The decompressor cross pin is the culprit which can dislodge itself..

The 2 pins are connected ......as shown below

tappet_pin-1.jpg

ignore the red arrows

I am going to install new cams today. If I where to remove the pin or pins, how is this going to affect my starting? what are the odds of the pin falling out? I've seen other responses, but once I do it, I can't undo it.

ok is it the pin right beside the black mark on the right or the thicker looking pin on the left just above the black mark?

The decompresser assembly is not a service part, it comes assembled on the cam and not available in individual parts either. The component parts of the decompresser assembly are not described in the service manual.

So wither you call the smaller pin, or the larger pin the "decompresser pin" is kind of moot point as neither have a name from Suzuki.

Anything we name the individual parts is just personal opinion and history from other brands or motors with like parts.

Failure is from the large pin fracturing at the hole for the smaller pin or the smaller pin fracturing and the larger pin moves out of place. either is bad :smirk:

I am going to install new cams today. If I where to remove the pin or pins, how is this going to affect my starting? what are the odds of the pin falling out? I've seen other responses, but once I do it, I can't undo it.

Good battery, clean wiring, jetted correctly, not a bigbore 13.5:1CR stroker motor? No difference..

And if you remove, you remove the whole assembly.. Just cut the weights and collar off with a dremel like THIS , air cut off wheel or the like, once the fall free, everything else does as well.

I just looked at http://www.thumpertalk.com/forum/sho...d.php?t=781803 I think I going to keep the pin in. If I get my hands on a manual decompressor I will take it off.

Dead link.

In any case.. your choice.. They do not fail that often.. when they do fail the broken bits case a mess.... Removing the assembly is easy. Of the dozen or more I've cut off for folks, I've never been told after it was an issue starting. Of the dozen or more Hot Cam installs I've done when the Hot cam did not have an auto decompresser, I've never had someone complain about starting issues.

The only DRZ engine I ever had a non auto decomp cam starting issue with was mine.. thats a 95.5mm BB, 5mm stroked, Old style Hot Cam stage 2, 13.5:1 CR piston motor,, and yes, it is a bitch to start without a decomp device and a very good battery.

so how do i now if this is the source of my engine knocking sounds ( check other post) or how can i tell if its b ad...when i rotate the engine with a wrench i can hear it click every rotation

so how do i now if this is the source of my engine knocking sounds ( check other post) or how can i tell if its b ad...when i rotate the engine with a wrench i can hear it click every rotation

Rotating the engine over will cause that click sound from the cam.. NORMAL.

Look at the pictures in the post I linked.. Look at you EX cam and the Decomp assy. If the pin is present, not angled, does not move laterally, looks to be in the same position , same alignment then the DECOMP is good. Me?? I still cut um off. :smirk:

By laterally do you mean in and out? Cause when I checked my valves last week I posted a picture and asked about this. Mine moves pretty much in every direction. Real loose like a loose tooth.

The larger pin that is.

By laterally do you mean in and out? Cause when I checked my valves last week I posted a picture and asked about this. Mine moves pretty much in every direction. Real loose like a loose tooth.

The larger pin that is.

Yes, in and out..

auto_decomp3.jpg

See the small pin?? See the gap on either side? The large pin should move laterally no more then the limits of that gap.. And should not wobble in the whole excessively.

Thanks for the reply. I think mine might fall into the category of excessive wobble. Just sitting there it is kinda tilted downward What should I do about this remove it? I will try to get some pictures.

The large pin with the flat that contacts the valve lifter is trapped in there regardless of if the small pin is in place or not. But if the small pin is missing, the orientation of the large pin is random and the small pin has likely been eaten by the motor. After having 1 break, I just remove the whole darn thing. It is not worth the risk to leave it in place. When you remove it, make sure you remove the "key" pin. I find the whole assembly removes easily by just breaking it off with a Crescent wrench (not in the motor of course)

ok, now i'm scared to ride my klx400r any futher without removing this auto decomp mess.i got a manual decomp assy. when i installed the backup kickstarter.i suppose i will install it and do away with the auto decomp.thanks for the info.i ride too far out in my area to have to worry about this .

rimtrail105

ok, now i'm scared to ride my klx400r any futher without removing this auto decomp mess.i got a manual decomp assy. when i installed the backup kickstarter.i suppose i will install it and do away with the auto decomp.thanks for the info.i ride too far out in my area to have to worry about this .

rimtrail105

Do you have an E? if not, without having the head modified, you cannot install the manual DECOMP. SSW can hook you up on machining the head for the manual DECOMP, or replace the head with an E unit.

klx400r model,it does have the place for decomp.bought the bike new in 03,sold it once then missed it and bought it back a year later.the guy i sold it to didn't ride it enough to keep the battery up and wanted something with a kickstarter..i didn't tell him you could put in a kickstarter,just bought it back.

rimtrail105

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