Yamaha 6hp No Start

[robinhood007]

thx for guiding

[sbl372]

Thanks for all the responses. When unable to restart, plugs are 100% dry. Using choke doesn't help nor does using more or less throttle. If engine re-starts it will run for few seconds then die. Once it restarted and ran sounding like it was firing on one cylinder.

[sawingknots]

what i meant by looking at the plugs was,when an engine is running too lean the plugs will be very white and the electrodes and ceramic portion will be pitted or blistered,as soon as the spark plug[s] cool off again the engine will start,the other possible cause is that bad or weak coils when hot tend to lose most of the thousands of volts required to run the engine, after the engine cools off it will run again,the only other possibe problem would be the engine is simply worn out and doesn't have enough compression,again made worse after the engine is hot

[dabnis]

Originally Posted by sawingknots

what i meant by looking at the plugs was,when an engine is running too lean the plugs will be very white and the electrodes and ceramic portion will be pitted or blistered,as soon as the spark plug[s] cool off again the engine will start,the other possible cause is that bad or weak coils when hot tend to lose most of the thousands of volts required to run the engine, after the engine cools off it will run again,the only other possibe problem would be the engine is simply worn out and doesn't have enough compression,again made worse after the engine is hot

Agree, if the plugs are dry it probably isn't flooding. What color were the plugs? Also has this come on gradually or did it just start? Do you shut the engine off or does id die on it's own? Any recent work done just before it started doing it? Maybe take out the sensor and ignition coils and have a shop test them? Or, just replace them . Carefully check high tension leads with an ohm Meter?

Dabnis

[sawingknots]

often its harder to determine whats wrong with an engine that will run but badly than an engine that won't run at all
keep the faith,you'll win in the end