Hey-
My name is Bill - just joined and am hoping to bounce a bike issue and maybe get an idea or two. I'm a retired computer nerd but probably more of a gear head . Been
restoring bikes and [mostly] cars for a long time. Moved into a new place with a big garage and heated basement 6 years ago and since then, been picking up a neglected
bike every year (mostly late 70s - 80s era sport bikes) to restore during winter then spray some on some fresh color when spring rolls in.
So now I've stupidly ended up with 7 restored bikes
( 3 '86 GSXR 1100s, an '86 VF1000R, 2 Kaw Z1Rs and an '80 CBX) Took the CBX for inspection yesterday. The bike has abt 27K on the odo and runs perfectly. At least it did
until yesterday. Like any other vehicle, it's had problems in the past but most of the time there is a clue or two, or where to look is obvious. It isn't this time although there
won't be time to look at it in depth until tomorrow. I left the inspection station and went for a short ride then headed home, Turning off a main highway onto a more "back road"
not far from home, I hit the brakes a little harder than usual and leaned the bike a little more than usual when I changed my mind at the last second regarding which route to
take. No peg dragging, squealing brakes or tires- just a little harder than usual to slow the bike from 55mph and make a turn. Coming out of the turn, I noticed a sudden
loss of power and the thing sounds more or less like a diesel. Made it back to the house ok. It will start and idle but there's not much power and it sounds awful.
No engine knock although the clutch has been noisy. I generally don't play hard w/any of these bikes - I doubt if I've ever revved it past 6K and even that would be unusual.
The one check I made so far was: before shutting it down I pointed an IR thermometer at each exhaust pipe thinking I might see a few cool readings but it seemed like
they were all close to the same temp. A couple years ago- the alternator went out on a 70 mile ride. The voltmeter needle was resting on "8" by the time I pulled into the
driveway and the thing was beginning to pop and buck. No popping or bucking this time but otherwise sounds a lot like it did then. Any thoughts would be much
appreciated!



cheers,
bill

 

welcome to the forum. have you checked to see if the carbs have dirt or sludge from the gas tank. when you slowed down hard, dirt in the gas tank sometimes loosen up and float into the carbs.

 

Thanks for replying- much appreciated. Had time to take a closer look at it last night, wondering if your suggestion was a possibility. Draining the #1 fuel bowl didn't show any
sludge although without actually pulling the bowl it's hard to tell. I checked a second time with the IR thermometer before pulling the tank. On starting the bike, the outside cylinders
warmed up much faster than the center 2 which never came all the way up to temp. Snapping a timing light pickup on each plug wire shows there is no spark going to cylinders 3 & 4.
The bike has 3 coils. Plug wires from the center coil go to cylinders 3&4. Maybe a strange coincidence this happened while turning a corner but will post back after I pull the tank
and get a closer look.

thanks again !
bill

 

Interesting- the coil checks out ok.