lazy cylinder in CB360T
JAC...@yalevm.ycc.yale.edu
My winter "rat" bike has started to do some peculiar things,
and I'm rather at a loss to know what to try next. Basically, if
the bike doesn't run for a few days--in 15-30 degree weather, it
refuses to fire on both cylinders when I start it. After some
period of time--usually about 3/4 of a mile--the second cylinder
kicks in and all is well.
I've changed plugs (the beastie came with Champion plugs; I
tossed those and put in some NGKs) but it hasn't done anything.
The "lazy" plug looked somewhat more carboned up, but I expected
that at the time, since the cylinder had just recently kicked
in at that point. It was *not* overwhelmingly fouled, however.
The bike is a 76 CB360T with 8800 miles on the engine. Engine
compression isn't great--about 100 on the lazy side, 110 on the
"good" side, but the compression *is* still fairly even.
Any ideas? This guy has to keep running for another couple of months
before the XS650 comes back from hibernation--and not much beyond
that--so it isn't a critical problem. It's just sort of annoying
when I'm gone for a weekend.
Funny, though: My 360 running on 1 cylinder has almost exactly
the same pickup as the CL175 I was just given by a friend. ;-)
-conrad j.
charles.a.rogers
>
> it refuses to fire on both cylinders when I start it.
> that at the time, since the cylinder had just recently kicked
> in at that point. It was *not* overwhelmingly fouled, however.
>
moisture and shorting until it gets hot. Or maybe the coil
(if there is a separate one) on the weak side has this
problem.
Chuck Rogers
att!druhi!car377
Chuck Karish
> My winter "rat" bike has started to do some peculiar things,
>and I'm rather at a loss to know what to try next. Basically, if
>the bike doesn't run for a few days--in 15-30 degree weather, it
>refuses to fire on both cylinders when I start it. After some
>period of time--usually about 3/4 of a mile--the second cylinder
>kicks in and all is well.
My CB750K does the same thing. The longer I leave it, the worse it
runs right after I start it.
I blame this on a leaky valve stem seal. Oil seeps past the seal
while the bike is sitting, and gets diluted with fuel and burned
off when the engine is running. My bike blows blue smoke from the
exhaust when I close the throttle, too.
My solution to the problem is to keep putting oil in, and wait for
a convenient time (after I fix my car) to pull the cylinder head
and replace the seals (and re-grind the valves, and dial in the
jetting, and other tedious tasks I don't want to think about).
Chuck Karish kar...@mindcraft.com
(415) 323-9000 kar...@forel.stanford.edu
Charles I. Ganimian Jr.
>Howdy!
>
> My winter "rat" bike has started to do some peculiar things,
>and I'm rather at a loss to know what to try next. Basically, if
>the bike doesn't run for a few days--in 15-30 degree weather, it
>refuses to fire on both cylinders when I start it. After some
>period of time--usually about 3/4 of a mile--the second cylinder
>kicks in and all is well.
>
>
>compression isn't great--about 100 on the lazy side, 110 on the
>"good" side, but the compression *is* still fairly even.
>
>the same pickup as the CL175 I was just given by a friend. ;-)
>
> -conrad j.
>
Check the battery. Old Honda's (I've had 72' SL350, 76' CB360T and
now a 76'CB400F) and you always loose 1/2 a moter (1 coil) with a low
battery. THe SL350 had a bad rectifier (sp?) and it would drain the battery
if I didn't disconnect the battery when the machine was off (used a switch).
One day I left a friend's on it running on 1 cylinder and about 2 houses
down the road the 2nd cylinder kicked in exploded the gas is the exhaust
and blew it wide open imbedding carbon in my arm... fun (I didn't own a
leather yet, it was summer... I was stupid, no jacket). Boy was that fun...
But all 3 of the bikes lost a coil if I let the battery get low, I'd start
there.
good luck
charlie g.
Hey CO gang I'm trying (to no avail) to talk my wife (Rachel) to ride out
to meet you folks for "THE RIDE" but she says my 400 won't make it and
she is tired of doing FJ cargo vehicle (ala chuck) imatations :-)
Hey NE folks lets do an east coast ride with a grand finale of the MT.
Washington auto road... or mabey go up Tuckerman's for those of you
who drool about Rollins Pass (like me :-)) any interest???
Ken Snyder
> it refuses to fire on both cylinders when I start it.
> that at the time, since the cylinder had just recently kicked
> in at that point. It was *not* overwhelmingly fouled, however.
>
turned out to be a combo of what Chuck already mentioned (I had cracks
in the insulation which filled with moisture and drained the electrical
system) and the seal around the chamber where the points were. I was
getting moisture coating the points (one set in particular) and that
caused a lack of firing when cold. When it got warm enough to evaporate
the moisture, viola! a 2 cylinder bike again.
Ken `2 wheels good' Snyder
ps. Permatex fixed my seal problem. There was no gasket.