My dirt bike (xr80) was running fine yesterday, but when I went to start it today it wouldn't start.
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1979 Honda XR80 problems! Help!
- Thread starter Iwantablaster
- Start date
If you're gonna figure it out, you're gonna have to do some testing on your own. No one can tell you, "I'm pretty sure it's the 7th fetzer valve". For any engine to run, it needs 3 things
Compression
Spark-- At the correct time
fuel
and in the case of a reed valve 2 stroke it also needs good reeds and an airtight motor.
Compression--Screw a compression gauge into it and see if it has at least 100 PSI of compression.
Spark-- Plug the plug wire onto a clean spark plug. Hold it against the head while you have someone kick it over. Watch for spark.
Fuel-- If you pull the spark plug out and it's wet with gas, you're getting fuel. If it's dry, pull the hose off the carb and open the petcock and see if fuel flows. If you're getting gas there, open the drain screw on the carb and see if fuel runs out.
Reeds-- with the carb off, look in at the reeds. You may be able to see if they're chipped or broken.
If ALL that passes, it may be a sheared flywheel key or an air leak in the motor.
Do NOT under any circumstances spray starting fluid into it.
Compression
Spark-- At the correct time
fuel
and in the case of a reed valve 2 stroke it also needs good reeds and an airtight motor.
Compression--Screw a compression gauge into it and see if it has at least 100 PSI of compression.
Spark-- Plug the plug wire onto a clean spark plug. Hold it against the head while you have someone kick it over. Watch for spark.
Fuel-- If you pull the spark plug out and it's wet with gas, you're getting fuel. If it's dry, pull the hose off the carb and open the petcock and see if fuel flows. If you're getting gas there, open the drain screw on the carb and see if fuel runs out.
Reeds-- with the carb off, look in at the reeds. You may be able to see if they're chipped or broken.
If ALL that passes, it may be a sheared flywheel key or an air leak in the motor.
Do NOT under any circumstances spray starting fluid into it.
The good news is that your bike is old enough to have points, so no electronics to deal with. The obvious things to look for would be wires melted to the exhaust or the kill switch wire rubbed through somewhere and shorted out. If all that looks good, it might be the points. Here's a thread I found about your bike.
http://www.thumpertalk.com/topic/579840-cant-get-spark-from-1979-honda-xr80/
No spark ..
Check kill switch/ignition switch for shorts....replace plug ....see if plug cap on coil wire is tight , if not cut 3/8 off plug wire and reattach .... check all ground wires and battery if used.
.More advanced testing...remove side cover re set point gap ,test condenser. Pull flywheel to see if key is sheered,check stator coils for ohms and shorts.
Check kill switch/ignition switch for shorts....replace plug ....see if plug cap on coil wire is tight , if not cut 3/8 off plug wire and reattach .... check all ground wires and battery if used.
.More advanced testing...remove side cover re set point gap ,test condenser. Pull flywheel to see if key is sheered,check stator coils for ohms and shorts.
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what have you tried to solve this so far???
fresh gas bought like today
new plug/or gapped properly 4 poke??
I will need to check that stuff on Monday. I had to go to my moms house, and didn't have time to look at it.
