Engine Will Not Idle, Idle Speed Too High; Engine Stops When Throttle Trigger Is Released - Stihl BR 800 Service Manual

Check the following
14. Check resistance of ignition lead.
Is resistance of ignition lead less than
10 Ω?
15. Is flywheel damaged?
16. Have pole shoes turned blue?
17. Is spline in flywheel hub in place and
undamaged?
18. Test ignition system with ZAT 3 or
ZAT 4, @ 13.2.
Sparkover?
19. Does condition still exist?
4.7

Engine will not idle, idle speed too high

Check the following
1. Test engine for leaks, @ 19.3.
Are oil seals or the crankcase
leaking?
2. Is throttle cable stiff?
4.8

Engine stops when throttle trigger is released

Check the following
1. Is MDG 1 analyzer available?
2. Remove air filter and install new air
filter.
Does condition still exist?
3. Piston seizure?
4. Is throttle shutter fully closed?
5. Test tank vent, @ 10.4.
Is tank vent OK?
6. Is fuel system leaking?
6
Yes
Go to 15.
Replace flywheel, @ 13.3.
Go to 16.
Replace flywheel, @ 13.3.
Go to 17.
Go to 18.
Go to 19.
Look for fault in fuel system, test
engine for leaks, @ 19.3.
Repair completed.
Yes
Replace oil seals, @ 20.4 or seal up
or replace crankcase, @ 20.4.
Go to 2.
Replace throttle cable, @ 14.2 and
@ 15.2.
Repair completed.
Yes
Create diagnostic report.
Test blower with MDG 1 analyzer.
Repair completed.
Reinstall the old air filter.
Go to 3.
Replace cylinder and piston, @ 20.5.
Go to 4.
Go to 5.
Go to 6.
Replace fuel hoses, @ 8.2.
Repair completed.
No
Replace ignition lead, @ 13.5.
Go to 15.
Go to 16.
Go to 17.
Replace flywheel, @ 13.3.
Go to 18.
Replace ignition lead, @ 13.5.
Go to 19.
Repair completed.
No
Go to 2.
Replace carburetor, @ 8.2.
Repair completed.
No
Go to 2.
Clean old air filter properly or fit new
filter.
Repair completed.
Go to 7.
Adjust throttle shutter correctly, @
9.4.
Go to 5.
Fit new tank vent, @ 10.7.
Go to 6.
Replace carburetor, @ 8.2.
Repair completed.
BR 800