[Flaekingr]

Hey folks, me again.

So I pulled the bike out today to check the things advised from my previous post. Went to kick it over and it's got no compression at all, I can use the kicker effortlessly with my hand. First thing I checked was the decomp, all well there. Went over the rubber hose attaching the carb and the spark plug, no obvious issues.
I thought I'd jump on here for some ideas of what to check next. Could my gaskets have somehow deteriorated over winter to the point where there's no compression? There's a slow seepage of oil from the bottom of the barrel that has been a thing for at least 6 months...

Anyway, help and advice always appreciated. Gotta get it started before I can move on to the other issues.

[AzCal Retred]

Rust on the valve stem can stick the valve a bit open. The tappet clearances should be too big if this is true. If they are tight, loosen them up a bit. Fog in some WD40 and keep trying.

[stinkwheel]

One possability is the rings being a bit sticky in their grooves. One way of dealing with that is to mix a little oil and petrol and stick it down the plughole, turn over a few times then allow it to pickle for half an hour. If a valve is sticking open, it should be obvious if you pop the tappet cover off and turn the engine over, the pushrod on the affected valve will remain tight.

If the valves are moving as they should do and it turns over freely, I'd just try starting it. My 350 used to lose compression when parked up but it still used to start and as soon as it had fired, whatever was causing the problem seemed to go away.

[Paul W]

My 350 did this once. It stopped suddenly at idle after a layoff and like yours there was no compression at all. I stripped the head and found a small nugget of carbon was holding the exhaust valve off its seat. I think if I’d kicked it over a few more times it might have sorted itself out.

You could start your trouble shooting by checking the tappet clearances then removing the rocker covers and checking the valves open and shut normally.

[SteveThackery]

Before removing anything I would put a little something into the cylinder, just in case the rings are sticking. Some anti-seize liquid, or paraffin/kerosene, diesel and petrol mix, etc. Anything like that should help. Leave it overnight.

If there is still no compression the next morning, then is the time to open the valve covers and look for a sticking valve. One sign would be an extra-loose push rod. (I think @stinkwheel meant loose rather than tight).

[AndyMcP]

I had the same issue yesterday morning.  Valves still in adjustment and de-compressor closing with a nice positive clack.  Squirted a bit of brake cleaner down the carb (I don't have east-start) and she fired up and was idling nicely after about a minute! 

[Raymond]

Mine has lost compression a couple times - I put it down to sticking rings. Starting the engine seems to sort it.

[mrunderhill1975a]

Is your decompressor stuck open?

[Pierric]

During winter times, I always watch the weather to ride the bike at least once a month from November to February. You just need additional basic thermal underwear and good winter gloves for that purpose here in France. Not only it a very pleasant to ride in the dry cold under the weak winter sun, not crossing any summer bikers and feeling like the road is yours, but it also prevents that kind of "spring start issues".
(Well I'm sorry this won't help you right now, but maybe for next winter).

[Paul W]

I normally ride through most of the winter; in fact that’s why I bought my 350 Bullet. However, the weather in U.K. this winter has been wet to a record breaking degree, as well as being cold. There’s been a lot of salt put down since Christmas. My bike stayed inside for almost three months but I did start it up and warm it every so often.

[allanfox]

I normally ride through most of the winter; in fact that’s why I bought my 350 Bullet. However, the weather in U.K. this winter has been wet to a record breaking degree, as well as being cold. There’s been a lot of salt put down since Christmas. My bike stayed inside for almost three months but I did start it up and warm it every so often.

It has been a horrible winter in the UK, not so much the cold but the wet, never seems to dry up for more than 5 minutes and as Paul says the road salt means a good wash ASAP when you get back.

[Paul W]

Getting back to the compression loss….Did this get resolved?