auto decompressor removal?

[petwar]

hi there, ive just bought a project xr600 with a possible auto decompressor fault. it sometimes works when i go to start it but sometimes doesnt and i have to use the manual lever. and aometimes it seems to hold the valve open when its running and it lacks power. so, is it an easy fix or should i just remove the thing?

[martinfan30]

Welcome to TT mate!

Have you tried/checked the valve lash? Do you have a quality spark and no fuel delivery issues?

[petwar]

thanks! yep, ive set the valves, got good spark and fueling slightly rich. the bike runs but sometimes it is extremely hard to kick over without the manual decompressor.

[martinfan30]

The auto decompressor can be removed. There is an oil passage that will have to be plugged though.

[petwar]

ive heard this, but i was thinking of just trimming the cam follower so it doesnt run on the decompressor cam. But is it a big or expensive job to swap the decomp assembly?

[martinfan30]

Not expensive at all. If you are any way mechanically inclined, it just requires removing the cam and sprocket.

Then just weld the oil passage shut.

[petwar]

ive not really got any worries about working on engines as im an engineer, but im just wondering how much the parts would be to sort out the decompressor? isnt the cam pressed on?

[Onederer]

ive not really got any worries about working on engines as im an engineer, but im just wondering how much the parts would be to sort out the decompressor? isnt the cam pressed on?

The sprocket plate is pressed onto the cam. If you have access to even a light press, that is all you'll need.

[petwar]

i mite give it a try then, anyone know roughly how much the parts would be?

[martinfan30]

i mite give it a try then, anyone know roughly how much the parts would be?

What parts? All you need is a press and a welder of some sort. If you don't have those, then they are pricey.

[Kenzo]

i wud fix it...the only things that would need to be possibly replaced are 3-4 springs some rollers and maybe a thrust washer...it shouldn't be expensive.

...u also need to make sure that the manual decompressor is working and adjusted correctly too.

kicking a 600cc bike without a auto-decompressor is not my idea of fun...

[petwar]

thanks for that guys, im guna strip it off and have a look at stripping it off and sorting it out. dont fancy a free trip over the bars lol!

[Kenzo]

thanks for that guys, im guna strip it off and have a look at stripping it off and sorting it out. dont fancy a free trip over the bars lol!

...or having the kick-start kicking back?

?

[PorterzCustomz]

I have manual decompression problems where it sticks open or it might be the auto doing it idk? Once the bike is running it does not appear to be an issue. Is it possible that it can malfunction and open up wile the bike is on? If so I might have to remove mine too. It seems to be getting progressively worse for me but IMO I NEED the auto decompression or I could not start it with my health. Better invest in the e start kit for it and bend over again to pay out my ass.

[Onederer]

thanks for that guys, im guna strip it off and have a look at stripping it off and sorting it out. dont fancy a free trip over the bars lol!

If you want to save $ on a rocker cover gasket, you could clean all the sealant from the old one and spray a couple of light coats of engine paint on it. Even if it completely dries before you put it on, it will seal. Just remember to set you valves a bit loose, cause when the paint seals the cover gets closer to the head. After riding an hour or so, you'll need to go over the cover torque and valve clearance once more. I have done it a couple times, and it works great. If its done rite you'll not have any leaks.