2 stoke strimmer popping

[TheBrick]

That sounds spot on. Yes the air filter has oil residue.

So it sounds like new engine if you're on about new barrel ?

 

[TheBrick]

I will have to price it up but before hand I will try a compression test on the cylinder thanks.

 

[jo1010]

I often see oily filters on good engines.....do a compression test first and tell us what reading you get.....

 

[Dapph2]

I often see oily filters on good engines.....do a compression test first and tell us what reading you get.....

AND a wet test immediately afterwards , using a tea spoon of clean engine oil .. it would not be unusual to see an increase of 10 PSI if it is worn due to the oil giving a temporary seal to the leakage .

Sometimes you can take the air filter off open the throttle and using a tiny LED torch look into the cylinder . It should look shiny on the cylinder walls not dull grey and the postin a very light grey with no bright streaks running top to bottom on the piston which would indicate metal pick up No scratches or scores on the cylinder skirt . . If you can easily get the exhaust off without wrecking the gasket or breaking studs you'll get an even better picture of the state of things.

 

[tom2207]

AND a wet test immediately afterwards , using a tea spoon of clean engine oil .. it would not be unusual to see an increase of 10 PSI if it is worn due to the oil giving a temporary seal to the leakage .

Sometimes you can take the air filter off open the throttle and using a tiny LED torch look into the cylinder . It should look shiny on the cylinder walls not dull grey and the postin a very light grey with no bright streaks running top to bottom on the piston which would indicate metal pick up No scratches or scores on the cylinder skirt . . If you can easily get the exhaust off without wrecking the gasket or breaking studs you'll get an even better picture of the state of things.

normally you can get a look in the cylinder well enough to judge from the exhaust port

 

[Dapph2]

normally you can get a look in the cylinder well enough to judge from the exhaust port

I've now got a small borescope that runs off my phone .up to 20 x magnification and with an LED illuminator adjacent to the magic eye. Not yet used it in a cylinder but for the £ 8 or so it cost me it's handy to have as I used it elsewhere . Was puling my hair out at first as the offered link would not work for me and my phone .

Fizzy gave it a try on his phone and at first it was the same, but then he downloaded a generic camera app and it worked.

 

[tom2207]

I've now got a small borescope that runs off my phone .up to 20 x magnification and with an LED illuminator adjacent to the magic eye. Not yet used it in a cylinder but for the £ 8 or so it cost me it's handy to have as I used it elsewhere . Was puling my hair out at first as the offered link would not work for me and my phone .

Fizzy gave it a try on his phone and at first it was the same, but then he downloaded a generic camera app and it worked.

at that price it would nearly be rude not to have one

 

[TheBrick]

ok just ran a compression test but missed the comment about doing a wet test.
Dry it was about 98psi so on the low side but not awful...

I will try to grab a wet and dry test later and take a look in the exhaust port.
Thanks for everyone's tips learning loads.

 

[TheBrick]

re did the pressure test and I miss read the gauge.
95 psi dry
~112 psi wet

Removed exhaust. Liite score marks are visible on cylinder a bit hard to see as still wet with oil. Nothing noticeable on piston.

 

[Dapph2]

re did the pressure test and I miss read the gauge.
95 psi dry
~112 psi wet

Removed exhaust. Liite score marks are visible on cylinder a bit hard to see as still wet with oil. Nothing noticeable on piston.

Those light score marks on the cylinder wall sound as that is what is causing a bit of crank case compression aka. blow back in the carb at high off load speed when the engine warbles and sluggish re- accelerations off load .

 

[jo1010]

Ok.....tbh "light score marks" could be significant....only way of telling is to take head off and see what's going on. 1). Once piston is out you can also check rings for sticking in the piston (jubilee clip to compress them again).....being jammed can be instant compression loss. 2) if you can feel scores on piston or cylinder with your fingernail its a problem that needs fixing though (new piston / cylinder).
Once fixed use new headgasket and honda seal or similar to seal up again...
....btw hs80 is a hedge trimmer not a strimmer ?

 

[TheBrick]

Ok will remove head thanks.

Those light score marks on the cylinder wall sound as that is what is causing a bit of crank case compression aka. blow back in the carb at high off load speed when the engine warbles and sluggish re- accelerations off load .

Crank case compression sound right as every so often the pop results in feeling pressure at air intake.

Ok.....tbh "light score marks" could be significant....only way of telling is to take head off and see what's going on. 1). Once piston is out you can also check rings for sticking in the piston (jubilee clip to compress them again).....being jammed can be instant compression loss. 2) if you can feel scores on piston or cylinder with your fingernail its a problem that needs fixing though (new piston / cylinder).
Once fixed use new headgasket and honda seal or similar to seal up again...
....btw hs80 is a hedge trimmer not a strimmer ?

Yes it is a hedge cutter. I don't know why I wrote strimmer :/ So head gasket and the honda seal. Is that because you are expecting the head to be out of true more than the gasket can take up / correct?