Stihl FS 81 First time starting problem

[mr ab]

I have a stihl strimmer fs81 strimmer recenlty serviced with a new fuel filter, carb seals, air filter etc as I was having trouble getting the engine to start on first attempt.

 

The service made it run smoother but I still have the same trouble starting the engine for the first time as you can't prime to engine on this model.

 

What I have to do is remove the spark plug and pour a little petol into where the spark plug sits.

 

Once I have done this it starts straight away and runs excellent.

 

Is there a better method I can use?

Is it possible to modify the engine to inculde a primmer?

 

Any help is appreciated.

Edited June 1, 2019 by mr ab
spelling

[mikerecike]

Immediate solution: Open the air filter cover, take out the filter, open the throttle, spray a bit of WD40 in, give the recoil a pull.

 

Thoughtful solution: For cold start - leave switch to off & pull slowly on recoil a couple of times to draw some fuel through the system. Switch to on & then choke or not depending on what works. (this approach sort of primes the system to fire in my experience)

 

 

 

 

[mr ab]

Many thanks for the reply.

I will try this as don't want to have to keep removing the spark plug.

 

Could I fit an inline bulb I can get one off ebay from china as below, but it looks like the pipe may be too big a diameter???

 

https://www.ebay.co.uk/itm/Universal-Primer-Bulb-100mm-Fuel-Hose-Line-for-Chainsaws-Brushcutters-Trimmer/292232170147?epid=2213074129&hash=item440a650aa3:g:o9cAAOSwAc1ZsRvw

 

[GardenKit]

I would be checking that the carburettor has been correctly overhauled and the fuel pump diaphragm and gasket is in good condition, in the right position and sealing against the cover. Then check that the manifold gasket is good.

These things can have an effect on the efficiency of the fuel pump whilst doing the first few 'priming' pulls.

 

[lurkalot]

2 hours ago, mr ab said:

Could I fit an inline bulb I can get one off ebay from china as below, but it looks like the pipe may be too big a diameter???

You shouldn't need one if the carb and rest of the engine is in good order.  Check those parts outlined by GardenKit  above, that's a pretty good place to start.