Anyone with knowledge on strimmer engines?
Discussion
Hi,
I am having some really frustrating problems with a spear and jackson sjbc 30 petrol strimmer and brush cutter.
I shall jump to the knit and grit. Last year i started the strimmer with old/stale petrol and oil mix. After i learned of my mistake i drained the tank and stored it away untill now. The strimmer starts then slowly dies i can prolong it by revving but it will eventually die out. I have fresh petrol/oil mix cleaned spark plug. Helppppp.
Thank you.
I am having some really frustrating problems with a spear and jackson sjbc 30 petrol strimmer and brush cutter.
I shall jump to the knit and grit. Last year i started the strimmer with old/stale petrol and oil mix. After i learned of my mistake i drained the tank and stored it away untill now. The strimmer starts then slowly dies i can prolong it by revving but it will eventually die out. I have fresh petrol/oil mix cleaned spark plug. Helppppp.
Thank you.
Difficult one because very small two stroke engine manufacturers tend to cut various corners in, let say, the quality of design.
Old gammy petrol tends to form a resin which blocks jets, interfers with the needle valve operation in the float chamber etc.
Unfortunately the whole lot needs to come apart.
Old gammy petrol tends to form a resin which blocks jets, interfers with the needle valve operation in the float chamber etc.
Unfortunately the whole lot needs to come apart.
Simpo Two said:
All the people advocating petrol strimmers on another thread seem to be keeping their heads down 
Have you checked the air filter ?
Most problems with these little motors will be down to old fuel or crud in the fuel.
I put all fuel through a filtered funnel for my garden machinery
julian64 said:
Difficult one because very small two stroke engine manufacturers tend to cut various corners in, let say, the quality of design.
Old gammy petrol tends to form a resin which blocks jets, interfers with the needle valve operation in the float chamber etc.
Unfortunately the whole lot needs to come apart.
This is correct - but cleaning some of the minute carb parts and getting all of the hard deposits off the jet/needle assy is pretty much impossible. You need a whole new carb assembly, which should cost no more than 30 quid. Old gammy petrol tends to form a resin which blocks jets, interfers with the needle valve operation in the float chamber etc.
Unfortunately the whole lot needs to come apart.
Even with fuel stanbaliser added, the fuel/oil composition is highly susceptible to 'gumming', so if you use the machine infrequently and although it's a pain, you really should drain the fuel out of it.
Matt Harper said:
julian64 said:
Difficult one because very small two stroke engine manufacturers tend to cut various corners in, let say, the quality of design.
Old gammy petrol tends to form a resin which blocks jets, interfers with the needle valve operation in the float chamber etc.
Unfortunately the whole lot needs to come apart.
This is correct - but cleaning some of the minute carb parts and getting all of the hard deposits off the jet/needle assy is pretty much impossible. You need a whole new carb assembly, which should cost no more than 30 quid. Old gammy petrol tends to form a resin which blocks jets, interfers with the needle valve operation in the float chamber etc.
Unfortunately the whole lot needs to come apart.
Even with fuel stanbaliser added, the fuel/oil composition is highly susceptible to 'gumming', so if you use the machine infrequently and although it's a pain, you really should drain the fuel out of it.
If the float bowl has a drain on it, use that after the engine has stopped, just to be sure.
Edited by dilbert on Monday 14th June 16:34
I have checked the idle screw, air filter, choke. Im begining to think its more of a internal engine problem. I have took the carb off and gave it a once over did not go into it to much tho.
I will just have to keep fiddling with it i dont really want to just bin it because its only 2 year old with about 15-20 hours running time if that.
The other half is not to impressed as we seem to have our very own beanstalk growing and the garden needs a good goin over. I should just pave the whole lot and be done with grass cutting tools. lol
Thank you for your replies.
I will just have to keep fiddling with it i dont really want to just bin it because its only 2 year old with about 15-20 hours running time if that.
The other half is not to impressed as we seem to have our very own beanstalk growing and the garden needs a good goin over. I should just pave the whole lot and be done with grass cutting tools. lol
Thank you for your replies.
dilbert said:
More than that. If you can you should never cut the engine when you've finished. Turn the fuel off at the tank, and let the engine empty the carb out.
If the float bowl has a drain on it, use that after the engine has stopped, just to be sure.
I don't think it will have a float bowl. All the 'carb' consists of is a venturi shaped metal tube with a jet and needle built into it.If the float bowl has a drain on it, use that after the engine has stopped, just to be sure.
Edited by dilbert on Monday 14th June 16:34
Weed-whackers are designed to be inverted/operate at different angles, so a conventional carb (which needs to remain moderately upright) wouldn't work on these machines.
The first thing I would try on any non starting petrol garden machinery, would be to drain off the fuel from the tank, and replace with fresh, new fuel.
Then to help the machinery to start, remove spark plug and pour a drop of petrol down spark plug hole, replace plug and try starting the strimmer.
If that fails then take the spark plug out, and just give the same a clean, checking the gap, which should be 25 thou., then repeat the above.
For future reference you might like to download the following link;
http://finance.groups.yahoo.com/group/milling/mess...
Then to help the machinery to start, remove spark plug and pour a drop of petrol down spark plug hole, replace plug and try starting the strimmer.
If that fails then take the spark plug out, and just give the same a clean, checking the gap, which should be 25 thou., then repeat the above.
For future reference you might like to download the following link;
http://finance.groups.yahoo.com/group/milling/mess...
my 2 strokes on the blower, strimmer, chainsaw and all the other gubbings always stall the first few times you start them, just give it some serious revs and it blows out all the crap and works fine after that..
although this afternoon i snapped the chain on the chainsaw so will have a fun evening repairing s
t.
although this afternoon i snapped the chain on the chainsaw so will have a fun evening repairing s
t. Almost certainly blocked neoprene fuel pipe or carb jets, two stroke fuel is notorious for "gumming up" after a few months.
Change the fuel, fit a brand new spark plug, and if it still won't start therin lies your problem.....
Always always drain all the old fuel out in autumn, (before winter storage), and empty the float chamber..(if possible)
Change the fuel, fit a brand new spark plug, and if it still won't start therin lies your problem.....
Always always drain all the old fuel out in autumn, (before winter storage), and empty the float chamber..(if possible)
Andy no gooder said:
Ok people i have been messing around with this today i cleaned the spark plug put it back in started it up kept it alive for around 45-60 seconds. I pulled the spark plug back out and it was black again.
The piston seems to be like a black sooty type colour could this be the problem?
could also be too much oil in the mixture.The piston seems to be like a black sooty type colour could this be the problem?
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