Stihl HT75 tuning problems
- Thread starter dhes
- Start date
It is a bit fiddly. I took the spring connector and plug cover off an old strimmer and used that. It had two ends on the spring similar to a clothes peg. I had to line them up on the cable and squeeze trough using a pliers making sure the spring end was central on the cable so it would make contact with internal wire. I also stripped back a small bit of cable and exposed the wire on the top so I would be in contact with the spring connector.
upupandaway
Well-Known Member
- Joined
- Jul 3, 2015
- Threads
- 36
- Messages
- 620
You could but you shouldn't have to. I would clean it out first. I say this because the spring doesn't push very hard to keep the needle closed. -BUT- being a hacker that i am, you could try it but that means you can toss the general rule of thumb of 1.5\1.75 turns of the fuel mix screws, etc and have to wing it to get the right mix. Not difficult but can be frustrating- i say this from what i had to do to get current carb to work on the original FS80.
Last edited:
So I learned that the metering lever should be flush with the body for Zama C1Q-S159 carbs. I checked the lever which was below the body so adjusted the lever up and put back together after checking the needle was seating properly by blowing through the fuel nozzle. The engine then wouldn't start at all so I just left it at that. I later noticed fuel leaking out of the air filter while the engine was sat there. This leads me to believe that either the metering lever or diaphragm are not correct. I took out the diaphragm and had another look. I am not sure if the meter gasket is part of the diaphragm as per picture below. Zama show they are 2 separate items: http://www.zamacorp.com/tclist.html?cnum=C1Q-S157
The diaphragm also looks a little stretched but I guess this is normal as it needs to flex. I will try lower the metering level slightly to see if that makes any difference. After that I am out of ideas apart from replacing either the entire the carb or gaskets.
The diaphragm also looks a little stretched but I guess this is normal as it needs to flex. I will try lower the metering level slightly to see if that makes any difference. After that I am out of ideas apart from replacing either the entire the carb or gaskets.