Primer bulb wont prime!

[18 stoner]

Hoping someone can help me out with this one!

 

I have a MS192t that was running fine, was left on the shelf for a month or so, then wouldnt run up properly.

 

As my dealer had just sorted out a 200t of mine very well, I thought I'd pass it over to them rather than me having a go and struggling along.

 

After two full days of the carb being in the sonic cleaner, replacing all fuel lines, input line, primer bulb, full carb kit and many hours building and re stripping it, its no different. The saw has also been fully pressure & vacuum and compression tested.

 

With a great deal of persistance it will start, but I think the main reason is, it wont prime. Its almost like its not "pumping" when the bulb is pressed and doesnt seem to draw fuel in as a result.

 

The next step the workshop suggested was to fit a new carb, but to be honest at £100 +VAT, this is likely to make it uneconomical to repair, given the time and parts already put into it.

 

I've collected it from the workshop now and thinking of getting into it myself.

 

So over to you guys, if you can offer any help or info I'd appreciate it. I guess Im hoping there's something they have missed and would be an easy cure, but open to any suggestions!

 

.

[Charlieh]

check the hoses on the primer bulb are connected properly? also have they used the right size hoses to the primer bulb?

 

can you get it to prime with the filler cap open?

[Eddy_t]

Check it's connected right way round, short leg to carb

[18 stoner]

That was fast you two!

 

Thats the first thing on my list then:thumbup1:

[Eddy_t]

Yeah, I've just had the same problem 20 mins ago after I repaired mine, least stihl are easier to get into

[tree monkey]

is the diaphragm under the primer ok ?

[Tree Man Tom]

Had the same problem with stihl strimmer, took carb apart and replaced the rubber diafram things. Problem solved

[18 stoner]

Ok, done some checking. The pipes appear to be in right way round.

 

Ive tried blowing from tank filter towards carb, with bulb pipes off and no fuel comes through. Appears there is a blockage in the carb as it cannot be drawn in(as the bulb would do) or blown in from the input side.

 

For you Monkey, it did have a refurb kit fitted.

 

Starting to wonder if it looks like a carb:confused1:

[Rich2484]

I'm a bit confused now.

 

You blew up the pipe into the carb??

 

If so and you are looking for fuel to come through the carb, it won't appear if you are looking down the butterflies. As the meter valve will stop it.

 

Take the carb apart and use some carb cleaner in all the channels and holes to ensure they are all cleaned out. Have you tried blowing back down the fuel pipe from the bulb into the tank filter to make sure that is all clear?

[18 stoner]

Rich, it wont vacuum from the bulb end, with or without the tank pick up on, so i tried blowing from tank end to see if it would reach the bulb, but nothing.

 

Ive now removed the carb, and all pipework and tank filters are clear.

 

The bulb appears to be working fine too, but no way can I vac, or pressure either inlet or bulb side of carb.

 

Hope that's a little clearer.