Nice video you explain things very well I just picked this 400EX up for 650 bucks guy said it was locked up but rear end was locked up and has an intermittent tick and somebody on the Honda group told me to look into the decompression pin which led me to your video thanks
For anyone concerned you can actually just remove the pin and just shave the rocker ledge off and leave all the decomp stuff on the cam. I ran into this a while ago. Knew a guy who raced the old xr”s. (Same motor). And I was helping him do a top end one day and noticed the rocker had been ground off and he explained it was a old school trick all the xr guys always done. He said ideally you can remove the stuff off the cam but if you do that you need to weld up the holes like stated in this vid. But he said there isn’t any use in just leaving the can along. Even the pin you can leave it or remove it. He said they always just remove the pin and shave the rocker. And send it. Crazy how there isn’t more info on this. These are actually pretty bullet proof engines.
My 06 Honda 400 ex doesn’t have a plate decompressor and the pin and spring in it I’m guessing someone rebuild it and didn’t put it in. It’s not starting up on it’s own u have to bump it could those missing be the reason why it isn’t starting on its own
just replaced cam and timing chain, timing is good, compression good, spark is good! it started fine and revved good and when i let it idle it died and just cranks now! took it apart checked timing it’s good! put new spark plug and still just rolls over.. any ideas
Great video. Not a lot of people talk detail. Did the tack welds work? I am having issues with an xr650r auto decomp. Thinking of eliminating it as well.
Congrats great video man it helped me alot, hey bro would you please help me out by telling me how did you take off all the parts of the decomprsor away from the camshat? thanks
I have an H-Frame shop press. That's really the only way to remove it for reassembly. With any use of the shop press, you need to rig something up to pull the gear from the shaft.
If interested in removing the decompressor, you'll need a shop press. I pressed mine off and on just to check it and it wasnt difficult to setup and press out.
mrdattopet the rat exactly what i’m trying to figure out, just replaced my oem cam with bigger hotcams cam. now no compression, timing is right. (did spin clockwise by accident a few turns, (maybe 1/4 an entire engine cycle)) maybe an open exhaust valve?
@@caleb9490 , You may wish to pull the valve cover and watch the valves moving. You may have bent a valve if you turned it over with incorrect timing, thus no compression...?
Am I understanding correctly that there are 2 options for bi-passing the decompression? Option-1: cut off the rocker arm or option-2 remove the mechanism from the cam shaft and weld the oil holes shut and remove the pin and spring from the head below the cam? Or do all options? The video wasn’t clear on that. Please reply. Thanks
Great video Nolen. Thanks for taking the time to study this matter and share your discoveries. Cheers
Nice video you explain things very well I just picked this 400EX up for 650 bucks guy said it was locked up but rear end was locked up and has an intermittent tick and somebody on the Honda group told me to look into the decompression pin which led me to your video thanks
For anyone concerned you can actually just remove the pin and just shave the rocker ledge off and leave all the decomp stuff on the cam. I ran into this a while ago. Knew a guy who raced the old xr”s. (Same motor). And I was helping him do a top end one day and noticed the rocker had been ground off and he explained it was a old school trick all the xr guys always done. He said ideally you can remove the stuff off the cam but if you do that you need to weld up the holes like stated in this vid. But he said there isn’t any use in just leaving the can along. Even the pin you can leave it or remove it. He said they always just remove the pin and shave the rocker. And send it. Crazy how there isn’t more info on this. These are actually pretty bullet proof engines.
The decompression pin in the head? dealing with the same issue.
@@okayokayokay9753 yep.
My 06 Honda 400 ex doesn’t have a plate decompressor and the pin and spring in it I’m guessing someone rebuild it and didn’t put it in. It’s not starting up on it’s own u have to bump it could those missing be the reason why it isn’t starting on its own
Nice video. Thanks. How did you pull off the cam gear holder without breaking it?
i havea a shop press from harbor freight, i pressed the cam off the gear. i later reassembled it after freezing the cam.
@@nolengerke552 how dit you press it so it doesnt get force only on one side?
just replaced cam and timing chain, timing is good, compression good, spark is good! it started fine and revved good and when i let it idle it died and just cranks now! took it apart checked timing it’s good! put new spark plug and still just rolls over.. any ideas
Great video. Not a lot of people talk detail. Did the tack welds work? I am having issues with an xr650r auto decomp. Thinking of eliminating it as well.
I left the decomp functioning and did not tack weld anything.
Where did you push on the cam to get all of that off? I tried to push on the bolt whole tabs and it snapped
Congrats great video man it helped me alot, hey bro would you please help me out by telling me how did you take off all the parts of the decomprsor away from the camshat? thanks
I have an H-Frame shop press. That's really the only way to remove it for reassembly. With any use of the shop press, you need to rig something up to pull the gear from the shaft.
Did you end up welding the holes in the camshaft as described?
If yes, does it work OK ?
I put it all back to stock. No welding. You could look at other cams like hot cams to see if they have holes but i bet they wont in that spot.
So i dropped mine pulling the head & its electric start sp i don't have to worry about the pin in the head ?
Could that cause my bike to tick very loudly, bc my bike is and I don’t know what’s wrong, my chain is tight and all
We'll done!!
When I upgrade from oem to stage 2 hot cam do I just remove the decompression pin and spring in the head then just plop and giver basically?
yeah, pull the spring and ball with a magnet. make sure not to drop them. Then drop the hot cam in. expect it start slightly harder.
I would assume a new cam( hot cam) comes ready to drop in with decompression ring?
TBH, i believe hot cams does not include a decompression ring. Its not "necessary" but considered helpful. Some folks remove them.
Hot Cams do not have the decrompression setup.
So how do I take mine out? Mine just hits and I've redone the whole engine
If interested in removing the decompressor, you'll need a shop press. I pressed mine off and on just to check it and it wasnt difficult to setup and press out.
Now I also hear that those decompressors cause a loud ticking and go bad
do you need the deconpresor can you take it of and still run ok with starting
mrdattopet the rat exactly what i’m trying to figure out, just replaced my oem cam with bigger hotcams cam. now no compression, timing is right. (did spin clockwise by accident a few turns, (maybe 1/4 an entire engine cycle)) maybe an open exhaust valve?
I believe you can get rid of it, however i kept mine. Aftermarket cams do not have this option as proof.
@@caleb9490 , You may wish to pull the valve cover and watch the valves moving. You may have bent a valve if you turned it over with incorrect timing, thus no compression...?
Nolen Gerke yup bent a valve but i’m sure that was from when the cam chain broke while riding it
@@caleb9490 Even more possible/probable. My cam chain stretched and made noise, so i was able to detect prior to it breaking.
👍🏻👍🏻
Am I understanding correctly that there are 2 options for bi-passing the decompression? Option-1: cut off the rocker arm or option-2 remove the mechanism from the cam shaft and weld the oil holes shut and remove the pin and spring from the head below the cam? Or do all options? The video wasn’t clear on that. Please reply. Thanks