tonysuburb
New member
Put some new NGK plugs in and bike runs like sh*t. Putting original plugs back in. Now it's fine.
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New purchase 1986 K75 running poorly
- Thread starter tonysuburb
- Start date
pglaves
#13338
Is it possible that with the new plugs one of the plug wires was loose, but when putting the old plugs back in the wire did clip solidly into place?
tonysuburb
New member
1986 K75 sputtering till warmed up
I was having a problem with my K75 on start up. It starts and runs fine for the first 15 seconds then starts sputtering and popping. I changed out the temperature sensor and plugs and it still does the same. I then opened the top of the airbox and lifted the lid about 1" and the bike seems to run better and about 100 RPM higher. I'm stumped. Is the problem in the air delivery?
I was having a problem with my K75 on start up. It starts and runs fine for the first 15 seconds then starts sputtering and popping. I changed out the temperature sensor and plugs and it still does the same. I then opened the top of the airbox and lifted the lid about 1" and the bike seems to run better and about 100 RPM higher. I'm stumped. Is the problem in the air delivery?
tonysuburb
New member
Plugs are in solidly.
tonysuburb
New member
Put a set of Bosch plugs in, still runs poorly.Tony,
Did you check the gap on the NGKs before you installed them?
Are the NGKs resistor plugs?
pglaves
#13338
OK. So spark plugs don't seem to be the problem. Plug wires still might be but from here I would suspect fueling. "Runs poorly" can mean a lot of things. A more detailed description of the issues might allow us to bemore help.
That said, I would do two things. I would put aa few ounces of Isoheet (red bottle) to the fuel to absorb any water in the gas that might be present. If this is the issue the results would be evident very quickly. Next, I would add Techron Fuel Injector Cleaner per the instructions to a tank of fresh gas and go for a ride. If partially clogged fuel injectors are the issue it will take time and miles to get them cleaned up this way.
pauls1150
MOA #24991, south of Los Angeles
It's a clue, but doesn't necessarily point to the actual problem: in a fuel-injected system, more air will typically raise the rpm.
Have you already checked the valve clearances and throttle body sync? And, older K bikes are known to need new hoses in several places.
MODS - Can you merge this with his other thread...
[merged in from other thread!]
Have you already checked the valve clearances and throttle body sync? And, older K bikes are known to need new hoses in several places.
MODS - Can you merge this with his other thread...
[merged in from other thread!]
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Tony,
Sounds like an air leak.
Check the 2" diameter 90 degree hose between the top of the air filter box and the intake plenum or cracks or improper connection (most likely at bottom on the plenum end).
Also check the crankcase vent hose for cracks.
It could also be cracks in the rubber manifolds above or below the throttle bodies.
Will be combining these two threads soon.
