Stihl Ht 75 Owners Manual

30 english
HT 70, HT 75Standard Setting:Shut off the engine.
:Check chain tension.
:Check the air filter and clean or 
replace as necessary.
:Check spark arresting screen* and 
clean or replace as necessary.
:Check adjustment of the throttle 
cable and readjust if necessary – 
see Adjusting the Throttle Cable.
:Turn high speed screw (H) 
counterclockwise (max. 3/4 turn) 
as far as stop.
:Carefully screw the low speed 
screw (L) down onto its seat. Then 
open it one turn counterclockwise.
:Start and warm...

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Erratic idling behavior
Idle setting too rich:
:Turn low speed screw (L) clockwise 
(about 1/4 turn) until the engine runs 
and accelerates smoothly.
If the engine is low on power, check the 
spark arresting screen in the muffler.
:Lift spark arresting screen and pull it 
out sideways.
:Clean spark arresting screen if 
necessary.
:If screen is damaged or coked up, fit 
a new one.
:Refit the spark arresting screen.
* see “Guide to Using this Manual”Wrong fuel mix (too much engine...

32 english
HT 70, HT 75 If engine is down on power, difficult to 
start or runs poorly at idling speed, first 
check the spark plug.
:Remove spark plug - see “Starting / 
Stopping the Engine“.
:Clean dirty spark plug.
:Check electrode gap (A) and 
readjust if necessary – see 
Specifications.
:Use only resistor type spark plugs 
of the approved range.
Rectify problems which have caused 
fouling of spark plug: 
:Too much oil in fuel mix.
:Dirty air filter.
:Unfavorable running conditions, 
e.g. operating...

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Removing the Rope Rotor:Take out the screw (5).
:Remove the rope rotor very 
carefully.
The rewind spring is seated in the 
rope rotor and may pop out and 
uncoil if care is not taken. 
The pieces of broken spring may be 
under tension and fly apart 
unexpectedly when you remove the 
rope rotor. To help reduce the risk of 
injury, wear face protection and 
gloves.
Replacing the Starter Rope:Use a screwdriver to pry the cap (6) 
out of the starter grip.
:Remove remaining rope from...

34 english
HT 70, HT 75 :Carefully remove the parts of the old 
spring from the starter cover and 
rope rotor.
:Insert the new rewind spring in the 
rope rotor and, at the same time, 
engage the outer spring loop in the 
rotor’s recess – the wire retainer 
slips off in this process. 
If the spring pops out and uncoils, 
refit it in the counterclockwise 
direction, starting outside and 
working inwards.
:Go to Installing the Rope Rotor.
Installing rope rotor with rewind 
spring
:Carefully unpack the new...

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Fitting the Starter Cover:Push the upper mounting boss 
under the shroud –
line up the tank and push the lower 
part of cover onto the tank.
:Insert and tighten down the housing 
screws.
Secure cable lug (arrow) in position 
(if fitted on your machine).For periods of about 3 months or longer:
:Drain and clean the fuel tank in a 
well ventilated area.
:Run engine until carburetor is dry, 
this helps prevent the carburetor 
diaphragms sticking together.
:Remove the saw chain and...

36 english
HT 70, HT 75HT 70:Remove the chain sprocket cover, 
chain and guide bar.
:Use a screwdriver to remove the E-
clip (1).
:Pull the washer (2) and sprocket (3) 
off the gear shaft.
:Clean the stub of the gear shaft and 
lubricate with STIHL grease – see 
Special Accessories.
:Fit the new chain sprocket on the 
gear shaft.
:Fit the washer and E-clip on the 
gear shaft.
HT 75The chain sprocket is driven through a 
friction clutch. It may only be replaced by 
an authorized STIHL servicing dealer....

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Correctly sharpened chainA properly sharpened chain slices 
through wood effortlessly and requires 
very little feed pressure.
Do not work with a dull or damaged saw 
chain as it will increase the physical 
effort required, produce unsatisfactory 
results and a higher rate of wear.
:Clean the chain. 
:Check the chain for cracks in the 
links and damaged rivets.
:Replace any damaged or worn parts 
of the chain and match the new 
parts to the shape and size of the 
original parts by...

38 english
HT 70, HT 75 Furthermore, the angles must be the 
same on all cutters. If angles are uneven 
the chain will run roughly, not in a 
straight line, wear quickly and break 
prematurely.
As these requirements can be met only 
after sufficient and constant practice:
:Use a file holder
A file holder must be used for manual 
resharpening of saw chain (see table 
Sharpening Tools). The correct filing 
angles are marked on the file holder.
For checking anglesUse a STlHL filing gauge (see table...

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:Rotate the file at regular intervals 
while filing to avoid one-sided wear.
:Use a piece of hardwood to remove 
burrs from cutting edge.
:Check angles with the filing gauge.
All cutters must be the same length.
If the cutters are not the same length, 
they will have different heights. This 
makes the chain run roughly and 
increases the risk of breakage of the 
chain. 
:Find the shortest cutter and then file 
all other cutters back to the same 
length – it is best to have this...