2 stroke engines
 

Anyone an expert in the field?

I have a 2t hedge cutter, it has been fine for ages, but today it kept cutting out and was difficult to restart. Did this a couple of times, then a third time it wouldn't restart at all, took plug out and cleaned it, cleaned fuel lines, still wouldn't start, so I took the top off, and checked all electrical connections,coiuldn't find fault, re assembled, and tried to start it, eventually it did after a few tugs, then I switched it off, pulled the cord, and it started first time, finished off the hedge, and put it away.Can't be a case of overheating cut out, as the machine is air cooled, anyone got any clues?

wants a new carb.

andy

I'd try pulling the carb to bits, cleaning jets etc before going down the replace route.

Usually plugs with 2 strokes, especially if they have been stood, the oil tends to separate out then foul the plug. Easy to flood them too so then need a delay before they'll start, which is what that final check gave.

There is a bloke nearby who services and repairs garden machinery, so will get him to look at it. Im not confident in pulling it apart myself. Made tbis mistake in the past, thought I could do something myself, then had to pass on to someone to finish it off.

could be modern fuel. has it been stood over winter, apparently, modern non premium fules contain less preservatives than they used to and basic petrols contain 5% ethanol.

https://www.nortonownersclub.org/noc...eral/551269389


you can buy fuel preservatives nowadays: eg:


https://www.ebay.co.uk/itm/Bill-Hirs...8AAOSwlp1Z3JTr


nb: i have seen it forsale in tiny bottles:

I was told this when I got my stuff, but never had a problem leaving petrol on them. I still have the fuel they sold me.

as mentioned has oil and petrol separated and is oil blocking a fuel line.
try with choke on and choke off, is their an air filter to check

macafee2

In the first instance wack a new plug in.

. Its got new fuel n it, there wasnt much left in over winter.

cleaned fuel lines out Ian

If it happens again, I will try that.

A new spark plug, or at least a clean one that fires, is a good idea Rich. However, I would say it is 90% likely to be the carb.

Modern petrol turns into a gel and then crystalises, blocking the fine orifices in the Walbro/Zama type carbs. Also, Chinese diaphragms harden relatively quickly unlike the original Japanese ones - they use poor quality rubber. I would strip it down completely, remove all the gaskets, diaphragm, mesh filter screen etc. and blast all the orifices with carb cleaner.

Then rebuild with a new diaphragm kit.

It's a simple job provided one marks all the components to indicate positioning/orientation and preferably takes photographs during disassembly.

There are lots of good "how to" guides on Youtube.

https://www.youtube.com/watch?v=cDaOcNrS6BM

https://www.youtube.com/watch?v=EKXwoP9Pa1U