Help with a non runner...

[fixerupper]

Yeah I had a strimmer that would start and run but no power ...rebuilt the carb new diaphram ..put back together no change ...whipped of the exhaust ...cleaned out the crud ...now it works like new ...

 

[jimbo84]

Got some propper carb cleaner and stripped the carb again and gave it a blast out with cleaner.

Took the exhaust off full of fluid, engine is being flooded I think.

Got some easy start, waiting for the drill battery to charge then I’ll go at it with the fuel off and the easy start and see if it goes.

 

[angellonewolf]

if the bore is full then the exhaust will prob have some in so empty that out as well

you could (but not recomemded unless you are confidnet in your skills) remove the exhaust shake it if its got fuel in remove the fuel apart from a little and light it (with a long piece of paper or a light on a long stick)

this gets the airbox up to a good temp and removes the soot and carp and cleans an exhaust on a mower thats been tiped the wrong way and you get a very smoky exhaust

be sure not to put much in there as when it starts it will pop and most people jump if you put to much in there is very dangerous and can explode

otherhalf father used to clean exhausts by building a fire and used to get the metal a dull redish glow he said you should see what comes out at the end of it

 

[eLuSiVeMiTe]

if the bore is full then the exhaust will prob have some in so empty that out as well

you could (but not recomemded unless you are confidnet in your skills) remove the exhaust shake it if its got fuel in remove the fuel apart from a little and light it (with a long piece of paper or a light on a long stick)

this gets the airbox up to a good temp and removes the soot and carp and cleans an exhaust on a mower thats been tiped the wrong way and you get a very smoky exhaust

be sure not to put much in there as when it starts it will pop and most people jump if you put to much in there is very dangerous and can explode

otherhalf father used to clean exhausts by building a fire and used to get the metal a dull redish glow he said you should see what comes out at the end of it

Electric hob in the garden works well apparently to burn the crud out.

 

[jimbo84]

Wouldn’t run off easy start.

It’s getting a spark but wondered if the timing had slipped. Took flywheel off no way of the timing slipping so that’s all good.

Put back together, still wouldn’t run on easy start but got it to run on its own fuel, all be it very badly and rough.

Tried the spark plug in my bigger generator and that is fine.

I’ll chuck a new carb on it, reckon it’s worth it at a tenner but if that doesn’t work it’ll be getting launched across the yard followed by being booted into the scrapyard. Right royal PITA it is.

 

[angellonewolf]

not much that can go wrong with 2 stroke

piston rings/piston/bore
carb
spark plug
coil and gap
exhaust

 

[MCKDAVID]

generally all you need is compression, air, fuel and spark, and it will run.. maybe not well, but it'll run usually

For me, from the symptoms that you're describing, and the fuel in the exhaust, I'd definitely be at the carb ... if it's too rich or getting flooded because it's over flowing through the float bowl, it won't run. it's a shame it would cost more than a new carb to send to me, and I'd run it through my ultrasonic tank and send it back to you, but you're right for a tenner it's worth a pop, go for a new carb, pretty sure that will at least get it running, then you can fine tune it later.

 

[jimbo84]

generally all you need is compression, air, fuel and spark, and it will run.. maybe not well, but it'll run usually

For me, from the symptoms that you're describing, and the fuel in the exhaust, I'd definitely be at the carb ... if it's too rich or getting flooded because it's over flowing through the float bowl, it won't run. it's a shame it would cost more than a new carb to send to me, and I'd run it through my ultrasonic tank and send it back to you, but you're right for a tenner it's worth a pop, go for a new carb, pretty sure that will at least get it running, then you can fine tune it later.

The ultrasonic cleaners seem to work wonders on the carbs going off youtube. It does look very clean now it’s been stripped and cleaned a fair few times but there are so many tiny holes and passageways in it it could be blocked/dirty anywhere.

Thanks for your kind offer of running it through your cleaner but like you say, once posted there and back a couple of new carbs could have been bought.

 

[The_Yellow_Ardvark]

Rebuild the carb, refit. Use a bit of non setting gasket goo, or a new gasket.
Fill float bowl, disconnect the fuel supply, attached air filet and exhaust.

Try and start, it should run even for a few minuets. Rough at this stage is not important. If it doesn't run then we need to look else where.

You may get a spark outside the engine, but under compression it may be took weak. So follow the leads back and ensure all connections are clean. The magnet in flywheel may be dirty/rusty. Pop the fly wheel off and look.

With the flywheel off you will be able to check static timing, I doubt it has moved, but you are there.

Guessing fresh fuel. If not worth spending a few quid.

If al checks out it is the carb.

How much does the engine owe you?

Easy cleaner.

Ann summers small cheep toy, bust out the off centre cam motor. attach to cleaning tank walk away.

 

[MCKDAVID]

.... but there are so many tiny holes and passageways in it it could be blocked/dirty anywhere.

thats the key phrase right there must have cleaned and rebuilt dozens of these little carbs now, and frankly it's not worth the bother, straight into the tank and away you go, these small engine carbs are tiny, and the associated passages are even tinier, even the slightest bit of debris / crap can cause problems.

the rest of these wee engines are simple, timing - unless the keyway has sheared it's unlikely to be a problem, and even if it has moved it would have to be well out to not run at all, run rough as a badgers, yes but they would still run of a fashion. Same for compression - it has to be really low before it would'nt run at all. As long as your seeing spark i go straight to the fuel / carb, a quick check of the exhaust too wouldn't harm, but again it should still start and run even partially choked. Majority of cases I've repaired, it's carb related, especially with the modern crap fuel, leave any engine any length of time now, and you get running problems. the older stuff doesn't like it especially hoses and seals etc... ethanol... garbage

 

[The_Yellow_Ardvark]

@jimbo84

How friendly are you with you local MM?

May be worth a few choccy hob nobs to talk to them about their returns bins.

 

[jimbo84]

Rebuild the carb, refit. Use a bit of non setting gasket goo, or a new gasket.
Fill float bowl, disconnect the fuel supply, attached air filet and exhaust.

Try and start, it should run even for a few minuets. Rough at this stage is not important. If it doesn't run then we need to look else where.

You may get a spark outside the engine, but under compression it may be took weak. So follow the leads back and ensure all connections are clean. The magnet in flywheel may be dirty/rusty. Pop the fly wheel off and look.

With the flywheel off you will be able to check static timing, I doubt it has moved, but you are there.

Guessing fresh fuel. If not worth spending a few quid.

If al checks out it is the carb.

How much does the engine owe you?

Easy cleaner.

Ann summers small cheep toy, bust out the off centre cam motor. attach to cleaning tank walk away.

Yeah fresh fuel/oil mix to the correct ratio.

Had the flywheel off thisafty and all looks intact and clean behind there as do connections to the coil pack (or whatever it’s called).

Hadn’t thought of that it could well be poor spark under compression as it wasn’t left with bad fuel in, the guy I got it off said it was running fine then a few days later nothing. Also it not running on wd40 or easy start makes me question whether it is something else other than the carb allthough the carb does appear to be flooding the engine too.

Stands me at nothing as he just gave it to me as he needs reliability so bought a new one.

Will give it a go rebuilt as you describe.

@jimbo84

How friendly are you with you local MM?

May be worth a few choccy hob nobs to talk to them about their returns bins.

You’ll have to enlighten me on the MM abreviation?

Thanks to you and everyone else for the pointers.

 

[MCKDAVID]

think he means Machine Mart, but I may be wrong....

 

[The_Yellow_Ardvark]

You’ll have to enlighten me on the MM abreviation?

Thanks to you and everyone else for the pointers.[/QUOTE]


MM= Machine Mart.

Mind you Clarks used to do a good after market care.

Tell them you brought one from MM 11 months ago and the MM you brought it from keeps telling you to go to Clarks.

Worth a punt.

 

[Screwdriver]

There is one difficult disastrous and not uncommon issue that can leave you (and me) stumped.

Crankcase seals. If it's blowing out of the crankshaft seals or anywhere in the crankcase, it can't get a decent compressed charge and will run like a dog. Similar to bad ring seal but that should be a more obvious fault.

<edit> oh and timing of course if the flywheel has shifted position on the crank. Make sure it's not loose!

 

[jimbo84]

Rebuild the carb, refit. Use a bit of non setting gasket goo, or a new gasket.
Fill float bowl, disconnect the fuel supply, attached air filet and exhaust.

Try and start, it should run even for a few minuets. Rough at this stage is not important. If it doesn't run then we need to look else where.

You may get a spark outside the engine, but under compression it may be took weak. So follow the leads back and ensure all connections are clean. The magnet in flywheel may be dirty/rusty. Pop the fly wheel off and look.

With the flywheel off you will be able to check static timing, I doubt it has moved, but you are there.

Guessing fresh fuel. If not worth spending a few quid.

If al checks out it is the carb.

Done all this today, doesn't run off petrol but will run dog rough by pumping easystart into the bowl.

New carb on order.

 

[Screwdriver]

You cleaned out the exhaust?

 

[jimbo84]

You cleaned out the exhaust?

Removed it and haven’t refitted it yet, previous post was without the exhaust fitted.

 

[The_Yellow_Ardvark]

Removed it and haven’t refitted it yet, previous post was without the exhaust fitted.

You may find that the engine may need back pressure.

 

[jimbo84]

You may find that the engine may need back pressure.

Ah ok, that figures as there was a washer betweeh the exhaust port ogbthe cylinder and the exhaust itself, thevwasher had a much smaller hole in it than the exhaust port.