What's on your bench today?

[GardenKit]

Thanks a lot will - i saw that but don't really want to spend 15 quid for it if i can help it - and i presume that one's had a bit of use too. Reply much appreciated though.

The brake band you require is listed on the McCulloch IPL as an obsolete part, so I doubt you will get one.

 

I have a used complete assembly on the shelf ( actually on a complete non runner) PM if interested

[WorcsWuss]

My carb supplier does not have any pop testers at present, but this is the one you are looking for. I dont know if this is the best place to buy, or the right price, but its the thing you need.

Kart Carb Pop Off Tester Brand New Karting Best on Ebay | eBay

 

Great stuff, thanks...!

 

Stripped it down and reassembled it this evening, I had got the metering diaphragm and gasket the wrong way round , starts a treat now.

 

Haven't had a proper fiddle with it because it was half 9 by the time it was back together, but on factory settings it doesn't seem to want to idle very well, stalls out.....

 

Having changed the carb gaskets & diaphragms, presumably the prime suspects for this are crankcase leaks, air entering the fuel line or some blockage deeper in the carb. I've only cleaned the top & bottom out, I didn't venture into the jets yet but that presumably is the next job....

 

Should also be picking up some bits and bobs for my 460 tomorrow, so will get that one back up and running with new diaphragms in the carb.... Ordered a pair of longer felling dogs as well...

[GardenKit]

Great stuff, thanks...!

 

 

 

Haven't had a proper fiddle with it because it was half 9 by the time it was back together, but on factory settings it doesn't seem to want to idle very well, stalls out:

 

Factory settings are only really applicable to new equipment. As engines and carburettors wear they will require to be tuned accordingly to maintain the correct air/fuel ratio.

Therefore it would be quite normal to adjust the screws away from presets.

 

Increase the idle speed until it will run with the throttle trigger off. Then adjust the L screw to get the smoothest, fastest idle. Once obtained, lower the idle speed, retuning the L screw accordingly as required until the desired idle speed is obtained. Check for pickup from idle, the L mix may require a little turn to Rich. Tune the H screw again, then recheck the L.

 

If all this can be achieved with the screws no more than 1\2 turn from preset then you have not got too much to worry about. If more adjustment is required then start to look for the reason.

Good Luck

[WorcsWuss]

It was almost running at 1 & 1/4 turns out.

My Walbro carb rebuild handbook puts that as the factory setting, so theoretically 1 & 3/4 turns out will be acceptable. I think I'm going to be heading on towards 2 turns though to be honest....

HOPEFULLY I can get a bit more time on it tomorrow evening and get it running well, all things being equal it's looking promising, pick up was good.... looking forward to burying it in some wood!

[GardenKit]

An example of 'pop testing' as mentioned in an earlier posting.

 

The pop test failed on the first test, it popped off at 20psi but did not reset at around 10 psi as it should.

 

This is often caused by the viton seat of the needle being damaged, as was the case here, damaged needle on the left.

 

Fitted new needle and set height of metering arm with gauge, then rebuilt carb and repeated pop test. This time the seat lifted at 22psi and reseated at around 11psi, which is perfect.

 

 

 

[spudulike]

An example of 'pop testing' as mentioned in an earlier posting.

 

The pop test failed on the first test, it popped off at 20psi but did not reset at around 10 psi as it should.

 

This is often caused by the viton seat of the needle being damaged, as was the case here, damaged needle on the left.

 

Fitted new needle and set height of metering arm with gauge, then rebuilt carb and repeated pop test. This time the seat lifted at 22psi and reseated at around 11psi, which is perfect.

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Nice post Barrie, got a tester on its way, always been aware of the pop off test and the logic but only pressure tested to ensure a good seal and not tested the pop off point - like to invest in new tools now and then:thumbup:

[spudulike]

Been finishing off the Stihl 036, pressure and Vac tested the saw, passed both, put the carb and muffler back on and fired up fine, just got to tach it now.

[spudulike]

Been getting a Husky 345 ready for sale, needed a damn good clean, compression is good but have found a few issues on the sprocket and oiler worm drive - been fitted with a rim drive sprocket that isn't standard and it has damaged the worm drive.

 

Now need to get a sprocket and worm drive:001_rolleyes:

 

Always rated these saws as they are light and have plenty of go in them!

[mikerecike]

Does it mean that even if it holds 10psi (which is as far as i've got with this test) it could still be a malfunctioning carb if the pop off and re-seating isn't right?

 

Just to confirm (I've never pumped a carb to 20ish psi imagining that the diaphragms would break) you pump beyond the 10 to 20 - observe it pop then fall immediately back to a holding at 10psi? Is this a standard and recommended test or is there any danger of damaging dias/gaskets?

 

What are the symptoms of a carb that wont pop at 20 or wont reseat at 10.

 

I'm struggling with a strimmer carb at the moment that spits fuel out of the air filter side when I try to fire the engine (pull the recoil) - don't know if this is related to above discussion?

 

Thank you folks

 

Mike

[mikerecike]

 

Makita DBC 4010 brushcutter

on my floor whilst i sort out a bench. Attempting my first ever leakdown test with some home made gear. Absolutely refusing to hold any pressure with exhaust and intake blocked and air pumped through modified sparkplug - i guess that means the crank case is leaking and I need to tear down further?