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Hi everyone,

Just wondering if anyone could spare a few moments to have a look into my situation

I bought a second hand FS90 and it wouldn't idle and was bogging down. So I decided to take each part off and clean everything down then reassemble. The engine seems to have a good strong compression as it takes a good pull with nice enough resistance.

I've had the whole head off the shaft, all covers off, all intake system off, fuel tank off and exhaust system off and all been cleaned where needed.

The machine didn't come with an air filter which wasn't a good sign at first.

I have now installed genuine air filter, fuel pickup filter, and a external gaskets on the intake system. And have installed the specific spark plug for this model stated on the user manual.

I cleaned the carb, metering side and fuel pump side and reassembled parts as shown in parts diagrams.

The primer bulb will not pickup any fuel, before and after cleaning the carb.

The machine will not run without the choke.

It will start first or second pull everytime with choke on.

Please anyone could advise?

Please see these 3 videos of the machine in different circumstances:

https://youtu.be/58VpDTy7Mmk

https://youtu.be/puVHQJjkgRM

https://youtu.be/YS8v3eip5xs

Many thanks,

Jay

Looks like you have the choke setting symbols backwards. At the end on the video, you are choking it, and it is shutting down from being "choked".

You do need to turn up the idle speed a little.

Fish said:

Looks like you have the choke setting symbols backwards. At the end on the video, you are choking it, and it is shutting down from being "choked".

Click to expand...

Hi Fish,

Thank you for replying to my post!

Wow I can't believe it, I thought that symbol with the line straight down meant the choke was on but obviously it means it's off!

So top position is choke on and with the knob facing the right is the choke off?

And your other comment, you mean the bottom screw? Or the high and low speed screws?

Thanks!
Jay

Here is a pic of the back view of the carb mount. The screw on top needs to be turned clockwise to turn up the idle speed, it takes a t-27 torx tip.

Fish said:

Here is a pic of the back view of the carb mount. The screw on top needs to be turned clockwise to turn up the idle speed, it takes a t-27 torx tip.
View attachment 44740

Click to expand...

Brilliant! Thanks for the reply.

I will have a look at this shortly but I'm pretty sure that screw is nearly fully seated so not much movement left. I will let you know how I get on

Many thanks
Jay

Here is some different angles of the screw.

Hi fish, I have fully bottomed out that screw and the machine doesn't seem to want to idle. I now have brilliant trigger response when I touch the trigger to accelerate though. Any other ideas? Not sure where to set the bottom screw on the carb

What about this screw in the bottom of the pic??

Fish said:

What about this screw in the bottom of the pic??

View attachment 44751

Click to expand...

Shall I try to just open it all the way out or something like that?

Also, the high and low speed jets... What kind of tool do you need for adjusting those

Without the tool, I have done many things in the past. Try jamming a blue electrical butt connector on the head, and turning that. I have also heated up the tube out of a cheap plastic pen with a lighter, and pushing it in there, holding it steady as the plastic cools and hardens.