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Hard to pull


clivefreeman
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When i pull the starter on my pap pa 125 the compression stops me in my tracks. Ive tried taking the plug out and cleaning it, this sometimes helps. This only happens every now and then, am i flooding it.

It hurts my little pinkies, any suggestions !!

Get bigger pinkies :lol::lol::lol:

Yes to mucho fuel :D

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Hi Guys I am going to jump on this thread as we also have a HE paramotor which is also very hard to pull start in fact its near impossible..

It was getting harder and harder to pull but after a flight on Sunday it now near impossible.

I have taken off the pull start and it seems OK it recoils OK,

When I try to pull it with the pull start its now near impossible to pull, when I take out the spark plug it pulls no problems.. Any ideas the motor has about 10 hours on it..

I am sure I am not the only to have come across this..

Pete or anyone who has knowledge or experience with such issues.

Thanks

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Moster

Easy pull

Less weight

Loadsa power

Sorry...But on the good side, if your motor's got that much compression, atleast it's not clapped out. Put a thimble full of petrol/oil mix down the plug hole and pull it a few times with no plug. This'll help if old oil residue was making the problem. When was it last run ?

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Hey farmer dave!!

Thanks for the reply. A few questions.

Sorry...But on the good side, if your motor's got that much compression, atleast it's not clapped out. Put a thimble full of petrol/oil mix down the plug hole and pull it a few times with no plug.

How much is a thimble.. is this true.

http://wiki.answers.com/Q/What_is_a_thimbleful

This'll help if old oil residue was making the problem. When was it last run ?

Engine is about a year old only about 10 hours running time. It was run last Sunday being used nearly every weekend for the last 10 weeks.

Whats has causes the stiffness(bar the pun)

Once again thats for the replies.

Dara

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Sounds like the decompression hole is blocked up with carbon.

There is a small drilling that links the barrel to the exhaust port to allow gas to bypass when pulling the engine over. These periodically block with carbon which makes it almost impossible to start. I believe this is why the later engines had an external decompressor fitted.

To clean it you need to pass a small stiff wire through it or a small drill bit. I think you can get to it if you just remove the exhaust and the piston is at the bottom of it's stroke. Failing that the head will need to be removed.

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Sounds like the decompression hole is blocked up with carbon.

There is a small drilling that links the barrel to the exhaust port to allow gas to bypass when pulling the engine over. These periodically block with carbon which makes it almost impossible to start. I believe this is why the later engines had an external decompressor fitted.

To clean it you need to pass a small stiff wire through it or a small drill bit. I think you can get to it if you just remove the exhaust and the piston is at the bottom of it's stroke. Failing that the head will need to be removed.

Would that be the case on a pa 125 its less than a year old.

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Ok took the exhaust of and found the hole which is driled, thats all clear. Pushed a small piece of wire through. Also put a fimble of petrol through the spark plug hole and gave it a good old tug. Still very stiff compession, which only lasts a small while but then seems to come back. I think what it needs it a good couple of hours in the air, the piston is very black. Just need the wind to die down now!!

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Hey Clive

Have you contacted the manufacture about your issue.

As you know we are having the same issue with a HE 120 paramotor.

I got a reply this morning from HE which was a super fast turn around as I only sent it 5 hours ago

......

OK so we’ll send you a special gasket to lower the compression of your engine. The gasket is placed in between the crankshaft casing and the cylinder. It should do the trick.

.................

My friend thinks there is a block somewhere in carb as no fuel is reaching the piston head.

Its a bit of a learning curve for me but we are having a ratttle at it today.

My friend who owns the HE paramotor broke his foot yesterday in work so he is out of action for the next 7 weeks so he doesn't mind that his machine is not working.

Best of luck with yours, keep us posted on how yours works out.

Dara

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If it only happens sometimes, it sounds like the timing is very slightly too far advanced and it is kicking back, some machines do it more than others. The only solution (unless it's still under warranty) is to remove the flywheel, set it back a degree and tighten it all back up again.

Ok took the exhaust of and found the hole which is driled, thats all clear. Pushed a small piece of wire through. Also put a fimble of petrol through the spark plug hole and gave it a good old tug. Still very stiff compession, which only lasts a small while but then seems to come back. I think what it needs it a good couple of hours in the air, the piston is very black. Just need the wind to die down now!!
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If it only happens sometimes, it sounds like the timing is very slightly too far advanced and it is kicking back, some machines do it more than others. The only solution (unless it's still under warranty) is to remove the flywheel, set it back a degree and tighten it all back up again.
Ok took the exhaust of and found the hole which is driled, thats all clear. Pushed a small piece of wire through. Also put a fimble of petrol through the spark plug hole and gave it a good old tug. Still very stiff compession, which only lasts a small while but then seems to come back. I think what it needs it a good couple of hours in the air, the piston is very black. Just need the wind to die down now!!

I have now decoked head and piston, still getting violent kick backs. So im guesing timing is out by a degree, ok anyone know how to set the timing on a pa 125.

Thanks Clive

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We just fixed a similar problem on a Ros 125 where the timing had moved on the crank as they don't use a keyway. Also head needs to come off to clean out decompresser hole as one hole is vertical from the exhaust and cylinder hole is angled to meet the vertical one.

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Ok, so after an email from andy at skydragons my problem seems to be resolved. Quite simple realy just have to kick start it instead of pull start. Dont ask me why but it does not seem to kick back or have the feel of high compession on kickstart. I used to kick start it anyway , but just had some work done on it (snaped a bolt on flywheel) so thought i would start it by hand. It does not like it ,but loves a good kick up the arse!!

All seems fine , think i need to fly it now.

Thanks for your help guys

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  • 1 year later...

Hoping someone has some news as to why this would happen!

My pa125 has exactly the same problem as described above

just taken the head off ,cleaned piston checked ring, cleaned decompressor hole (wasnt blocked)

then broke the starter cord trying a start (obviously not fixed then ! )

any Ideas other than Timing?

no fuel in motor so not a vapour lock

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Mine was not the timing or squish, it was getting past a stubborn stage..

Found that it was much easier to kickstart than pull start, and it got much easier the more hours i put on it !!

I remember now ..

Only prime the bulb so the fuel only just reaches the carb it use to flood very easy which would cause it to lock out and kick back..

Tip the motor to one side and be gentle on the primer bulb, pretty sure this was the main cause of the problem…

How many hours have you on it have you checked the needle and membranes i replaced mine after about thirty hours !!

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Mine was not the timing or squish, it was getting past a stubborn stage..

Found that it was much easier to kickstart than pull start, and it got much easier the more hours i put on it !!

I remember now ..

Only prime the bulb so the fuel only just reaches the carb it use to flood very easy which would cause it to lock out and kick back..

Tip the motor to one side and be gentle on the primer bulb, pretty sure this was the main cause of the problem…

How many hours have you on it have you checked the needle and membranes i replaced mine after about thirty hours !!

Thanks clive ...yes I guess it has 30 to 40 hrs after a brand new carb was fitted ,the membranes dont look brilliant so will change them , however even with no fuel , no priming ,etc its still very hard to pull over, which was leading me to think along other lines ! off to buy some solder to measure squish, and will be interesting to see if thats spot on

a bit of update... squish measured and its reading 1.04 -1.20

recommended 1.3 - 1.5

so off to get some gasket paper tommorow see if that makes difference

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I have adjusted the Squish with a thicker gasket

but still the same problem !

Can someone tell me if the timing is out , would I not notice a difference between the sparkplug lead on or off ? if there is no spark then there is no advance? or could timing still be the cause.

if not then any other ideas please ?

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