- Posts: 534
- Thank you received: 20
Temperature of one exhaust pipe is much lower.
- car5car
- Topic Author
- Offline
- Banned
Any ideas? Thanks.
The cylinder works, RPM drops when spark plug wire removed.
96 Yamaha Royal Star
82 Yamaha Virago 920
Please Log in or Create an account to join the conversation.
- ThatGPzGuy
- Offline
- Sustaining Member
- More Sparky than Speed Racer
- Posts: 1489
- Thank you received: 385
Jim
North GA
2016 Yamaha FJR1300ES
1982 GPz750 R1
1974 Kawasaki H1
1976 Kawasaki KZ400
1979 Yamaha XS650 cafe'
2001 KZ1000P
2001 Yamaha YZ426
1981 Honda XR200 stroked in an '89 CR125 chassis
1965 Mustang
1967 Triumph GT6
1976 Bronco
"If you didn't build it, it's not really yours"
Please Log in or Create an account to join the conversation.
- Nessism
- Offline
- Sustaining Member
- Posts: 7507
- Thank you received: 2823
Please Log in or Create an account to join the conversation.
- jdvorchak
- Offline
- User
- Posts: 398
- Thank you received: 50
A little history helps a lot. New to you bike? You've owned the bike for years and this just cropped up? Bike been sitting for a while? Months? Years? Bad or rough idle? Pulling the spark plug on one cylinder is not really a good test like on an old car. These use wasted spark ignition and pulling one plug wire will shut of two cylinders most of time.
Don't fix it until it's broken.
John
83 KZ550M1
83 KZ1100LTD
Also own:
2010 Harley Ultra Classic Limited, 2008 Harley low rider 71 CB350/sidecar
Please Log in or Create an account to join the conversation.
- redhawk4
- Offline
- User
- Posts: 640
- Thank you received: 64
1978 KZ1000A2 Wiseco 1075 kit
1977 KZ650B1
1973 Triumph Tiger TR7V
1968 BSA Victor Special 441
2015 Triumph Thunderbird LT
1980 Suzuki SP400
Old enough to know better, still too young to care
Please Log in or Create an account to join the conversation.
- bountyhunter
- Offline
- User
- Posts: 7246
- Thank you received: 337
Carb balancing issue.car5car wrote: Temperature of one exhaust pipe is much lower at idle. Measured about 4" from head.
Any ideas? Thanks.
The cylinder works, RPM drops when spark plug wire removed.
1979 KZ-750 Twin
Please Log in or Create an account to join the conversation.
- 650ed
- Offline
- User
- Posts: 15344
- Thank you received: 2829
1977 KZ650-C1 Original Owner - Stock (with additional invisible FIAMM horn)
Please Log in or Create an account to join the conversation.
- car5car
- Topic Author
- Offline
- Banned
- Posts: 534
- Thank you received: 20
I cleaned carbs and adjusted valves about 2 years ago and didn't ride it since because I had rattling generator. Finally I fixed generator problem and then had to rebuild petcock and replace carb bowl gaskets.
I have infra red thermometer and was checking head temp to prevent overheating, then checked exhaust pipes
I guess my 4th cylinder is dead because exhaust pipe temp is lower than head temp. Adjusting mix screw didn't change anything.
Right now I have bunch of problems:
bowl gaskets leak (ordered good ones)
timing chain rattles
4th cylinder is dead(?)
no gauges illumination lights
headlight died for a few minutes when I rode the bike at night
if 15V is too high, I have a regulator problem
I need a plan, solving worst problem first (cylinder)
1.Check compression of 4th cyl.
2. Check spark plugs (I installed new ones yesterday)
3.If spark plug is dry, I'll do carbs cleaning/adjusting/synchr.
I rode about 2 miles yesterday, so new spark plugs should show something.
4.Check timing marks.
5.Adjust timing chain
What did I forget?
96 Yamaha Royal Star
82 Yamaha Virago 920
Please Log in or Create an account to join the conversation.
- redhawk4
- Offline
- User
- Posts: 640
- Thank you received: 64
1978 KZ1000A2 Wiseco 1075 kit
1977 KZ650B1
1973 Triumph Tiger TR7V
1968 BSA Victor Special 441
2015 Triumph Thunderbird LT
1980 Suzuki SP400
Old enough to know better, still too young to care
Please Log in or Create an account to join the conversation.
- car5car
- Topic Author
- Offline
- Banned
- Posts: 534
- Thank you received: 20
temperature of "dead" 4th cylinder is higher than 1st one! (measured next to spark plug)
OK, I'll check synchronizing before cleaning carbs.
BTW I cleaned petcock 2 years ago and it was clogged!
96 Yamaha Royal Star
82 Yamaha Virago 920
Please Log in or Create an account to join the conversation.
- bluezbike
- Offline
- Sustaining Member
- Posts: 598
- Thank you received: 104
79 KZ 1000 LTD
77 KZ 1000 B1 LTD (awaiting electrical resurrection)
Please Log in or Create an account to join the conversation.
- car5car
- Topic Author
- Offline
- Banned
- Posts: 534
- Thank you received: 20
I rode about 10 miles yesterday, bike ran perfect except some farting around 3K RPM(backfiring of frontfiring(?))! Still low temp exhaust pipe!!!!!!!!
I have pod filters and 4 in one exhaust pipes, so cannot check which cylinder is frontfiring (exhaust). I tried to hold hand next to filters, didn't feel anything.
I'll check spark plugs tomorrow. Backfiring happens around 3000 RPM, so it has nothing to do with clogged idle jet.
96 Yamaha Royal Star
82 Yamaha Virago 920
Please Log in or Create an account to join the conversation.