I've just been given an xs400 that ran "just" a couple of years ago. I cleaned the carbs and installed new carb kits. When I put them on the bike fired right up. However, it is only running on the right cylinder. It runs well enough that I can ride it with no problem, but still I'd like to have use of the whole engine. The left side gets spark, but doesn't run on that side. Any ideas on where to start?

Thanks.

I've just been given an xs400 that ran "just" a couple of years ago. I cleaned the carbs and installed new carb kits. When I put them on the bike fired right up. However, it is only running on the right cylinder. It runs well enough that I can ride it with no problem, but still I'd like to have use of the whole engine. The left side gets spark, but doesn't run on that side. Any ideas on where to start?

Thanks.

contact gaps (if fitted)

ignition timing

valves adjusting

coil parameters

check carb on that side

all gap info is previously posted, use the search facility

contact gaps (if fitted)

ignition timing

valves adjusting

coil parameters

check carb on that side

all gap info is previously posted, use the search facility

OK, so I'm checking all of the above, and I adjusted the left side exhaust valve to .008, when I noticed that slightly before and after the "LT" mark the gap is closer to 1/8" than .008. I checked the right side and it doesn't seem to do this. What am I looking at here? Also, if I run it set that way it makes some crazy top end noise - kind of a knocking sound. If I set it so that it is .008 at it most open point, of course it is completely shut at "LT".

Also, when I take the alternator cover off to get to the timing marks should it drain oil out the bottom? None of the maint manuals mentioned that, and I'm new to this.

Thanks--

OK, so I'm checking all of the above, and I adjusted the left side exhaust valve to .008, when I noticed that slightly before and after the "LT" mark the gap is closer to 1/8" than .008. I checked the right side and it doesn't seem to do this. What am I looking at here? Also, if I run it set that way it makes some crazy top end noise - kind of a knocking sound. If I set it so that it is .008 at it most open point, of course it is completely shut at "LT".

Also, when I take the alternator cover off to get to the timing marks should it drain oil out the bottom? None of the maint manuals mentioned that, and I'm new to this.

Thanks--

LT is left timing for the valves on that side

RT is the right timing for the valves on the right

make sure the piston is at TDC by removing the sparkies and feeling compression with your thumb.

inlet (carb side) is 0.08 - 0.12 mm

exhaust 0.16 - 0.20mm

A little oil does come out and my engine has only 2k since rebuild

LT is left timing for the valves on that side

RT is the right timing for the valves on the right

make sure the piston is at TDC by removing the sparkies and feeling compression with your thumb.

inlet (carb side) is 0.08 - 0.12 mm

exhaust 0.16 - 0.20mm

A little oil does come out and my engine has only 2k since rebuild

When you say a "little" oil comes out, how much is a little? I got most of it, probably 1 - 2 litres.

When you say a "little" oil comes out, how much is a little? I got most of it, probably 1 - 2 litres.

erm..no

thimble full at most

there's no seal there, maybe try tightening the case bolts. 8mm = 2.0 - 2.4 lb ft 6mm = 0.8 - 1.2 lb ft

ps I am talking about the left side of the bike (as you sit on it) as the engine only takes 2 litres (2.3 with new oil filter) so hopefully your not removing the clutch side?

erm..no

thimble full at most

Can I jump in here? Mine drains all the oil when I remove the left hand cover to access the timing disc. Is this normal for the DOHC version?

No, this is the left side, the oil comes out thru the small hole at the bottom. One thing, though, I figured while I had most of the oil out I might as well do the full oil change. So when I took the oil filter off I noticed the innards were in backwards - with the spring pushing the filter away from the case and the seal against the filter holder. Perhaps that didn't help.

Anyway, I checked again to make sure I had TDC and it was and gapped correctly. Still if I move it slightly off TDC I get a gap of about 1/8th inch (3-5 mm) on the exhaust valve. Intake is normal. Maybe a problem with the rocker arm? Will it hurt anything if I just run it as a one cylinder? This sounds like it could get more intrusive than I'm wanting. I just want to ride the thing.

Also, would it be better to tighten the gap down completely (so that there is no knocking noise, but no gap) or adjust it so that the gap at TDC is correct, but knocks badly?