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cylinder and head for walkerjet paramotor


lee_d
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I seem to remember that when i had a Walkerjet that the Fly 200 engine did experiance a heat problem and that an upgraded bigger head was called for sadly my engine detonated within a 2 hours of new so never got that far.

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Lee, the good news is that parts for the Walkerjet F200 are MUCH cheaper than most other motors. Prices in 2010 were (Euros) €162 for cylinder block, €54 for the head, €60 for complete piston set (with pin, rings etc) and €9 for full gasket set.

Bad news is it might take a few weeks for delivery - speak to Patricie at Walkerjet - although not perfect English she was very helpful.

I never had the slightest problem with overheating, using the earlier (smaller) cylinder head. The piston and everything was like new when I did a service rebuild. It is a brilliant engine with tons of power and much lighter than the equivalent Simonini. The silencer could be improved though as I found it a bit noisy.

If you are doing a rebuild you might want to use a dremel or similar to carefully smooth out any rough casting from the ports, and polish up the inside of the cylinder head. The cylinder itself is Nicasil coated so don't touch that.

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  • 1 month later...

Hi Guys

I also have a walkerjet 200 with a fly 200 engine which i bought with a blowen piston and cylinder. I have tried to contact patrica in walkerjet by email but with no sucess have you got a valid phone number fo them is there anywhere else i can buy the parts i need . this engine has done this twice on the previous owner i dont think he has changed the head to a bigger one . have you any idea as to what could be causing this . Would really apprecaite any feed back to cure this problem .

Regards

Iain

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Hi Iain,

Don't give up on Walkerjet as they are always a bit slow to respond, but genuine & helpful when you do get through to them. They had a stand at St. Hilaire last year with lots of motors on display.

If you need the parts quickly you could contact Andy at Skydragons.co.uk, or order them from Airfer, Pap, PXP or any other manufacturer that uses the F200 engine.

As for the root cause, the most likely is a lean mixture, either from carb or an air leak into the crank case somewhere (probably the base gasket). Otherwise it could be the ignition advance timing set incorrectly.

Can't remember how many hours mine had done when I last serviced it but the piston, barrel & cylinder head were still like new & unmarked, with massive amounts of power for me (105kg) - and that was with the original, smaller round cylinder head.

Alan

5733640d378a1_Walkerjetservice(4).jpg.46

5733640d3aeaa_Walkerjetservice(12).jpg.0

5733640d3e6c2_Walkerjetservice(20).jpg.a

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Hi Alan

Thanks for the help i have been in contact with fly engines to price the parts because i still cant get walkerjet but i have attached a few pics of the engine i have broken it down and i would love to hear your view as to what may have caused this problem . All the damage seems to be on the exhaust side of the piston and cylinder ,Im not sure but anyone that understands two stroke engines will know this means something hope you can help

regards

Iain

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5733640da3b90_fly200engine041.jpg.8aa820

5733640da6c14_fly200engine044.jpg.006d1f

5733640dacd4e_fly200engine045.jpg.336e7c

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You need to find out what has broken up and got dragged through the exhaust port, rings? or maybe a bearing breaking up?

I recently fitted a new piston only to find out it was 4mm longer at the base and was hitting the crank case so had to strip it back down and have it removed from the bottom of the piston,

check the new piston is the same size as the old one

Pete

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It certainly looks like your lower ring is missing - probably broken up and caused all the scoring to piston and cylinder... Hard to guess the cause without knowing how fastidious the previous owner was with the rebuild, ie if he checked all the tolerances first and followed the strict warm-up / break-in procedure.

I would suggest changing the crank bearings and reed valves as well now it is disassembled, then once you fit a new cylinder & piston assembly you should have essentially a brand new engine again.

When I rebuilt mine I filed a tiny lip around the exhaust port to remove the knife edge around the inlet (a potential source of overheating) and smoothed off the rough casting in the ports with a dremmel type tool. Give the piston and cylinder head chamber a good polish with Autosol or similar. Remember to keep everything thoroughly clean & lubricated during re-assembly, and check all clearances and everything moves freely before you fire it up.

Order a few spare cylinder and head gaskets so you can inspect at regular intervals (they cost buttons and it is only a half hour job to do even when the engine is all fitted in the frame). Carbon deposits can cause localised overheating so best to remove them.

Don't forget the F200 engine squeezes out an equivalent power of 135Hp / litre - similar to a top race kart engine which would be rebuilt after a few races ..... :o

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Hi lads

It definately seem to be the lower ring that broke on the exhaust side but this has happened after 5 hours run in and 3hours flying time according to the guy i bought it off. The engine first give up the ghost 15hours from new so im told then he rebuilt it and it happened again and then i bought it off him because he was fed up by this time. So it not wear and tear its either wrong mix or adjustment the first time or something like that and maybe a bad rebuilt the second time or could it be something wrong in the engine from the factory when new ??? Either way i dont want it to happen again so trying to gather as much info as possiable .

Iain

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Check the piston is the right way round .. sounds daft but some are handed.

The other common thing is if any porting work on the exhaust has been done the port has been enlarged too much and allowing the ring to expand into it as it passes that kills rings and pistons pretty fast.

Or if there has been a previous blow up not getting the bore properly clean of debris. Speaking of debris the bottom end of yours will have bits in it . A good wash out with paraffin should sort it but to be totally sure you would need to strip it and renew the bearings just in case.

Hope im not teaching you to suck eggs.

Cheers Col...

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Strip it right down and clean/replace as necessary. or it could/will happen again.

It wont take long when you do it and you will have peace of mind that you know it is all in A1 condition.

OR just stick it back together and when ever you fly it you will be worrying that it might go bang at any minute rather than enjoying the flight!!

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  • 1 month later...

macauto 123123 have you figured out you problem yet. im telling ya theres a good chance you got a crank case leak. over here in n,b canada and i felt like chopping up my walker jet untill i learned how important it is not to have ANY LEAK AT ALL in a crank. it makes the motor heat up, and heat is the number 1 piston,cylinder and ring destroyer. im telling ya it took me 3 motor jobs to figure this out.

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  • 4 months later...

Hi Bobby as you can see i havent been on here in quite a while havent got anything sorted out yet i cant get fly engine to repley to my calls or emails but im very keen to check out your idea of crank leaks sound excitly what could be wrong how do i carry out this test do i build up the engine with new parts and turn the engine over by hand while having soaked the crank gasket in soapy water to see if it blows bubbles is there enough of back compression the the block to tests the seals are am i way off the mark. very intrested to know

regards

iain

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Hi Iain,

I had the same problem as in your photos with the F200 engine, I showed it to someone that specialised in reconditioning 2 stroke engines, he told me the exhaust port was not properly rounded and the piston ring was catching on the sharp edge. He suggested I could round it off with a a grinding stone on a rotary tool like a Dremel. I told Fly engines and they send me a new cylinder and the problem was solved.

Paul Deakin

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Hi Paul

The photo's were from my rebuild - which did not have a problem. :wink:

I used a standard half-round file to take the sharp edge off the exhaust port (less chance of damaging the cylinder coating) and the dremel to smooth out the casting in the exhaust port.

Going to look at my Simonini Evo this week and see if that will benefit from any porting / gas flow work.

+420 776 555 509 was the number I used to call Patricie at Walkerjet for cheap spares for the F200 engine. Email: info@walkerjet.cz

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:oops: Sorry Paul - my internet is playing up and I missed those .......

Hoping my Simonini isn't suffering the same fate, or a broken oil control ring. Have to remove and clean the plug before each flight as it gets totally drowned in oil. Didn't get this on my F200. Does anyone else suffer this on motors with the spark plug on the bottom ?

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:oops: Sorry Paul - my internet is playing up and I missed those .......

Hoping my Simonini isn't suffering the same fate, or a broken oil control ring. Have to remove and clean the plug before each flight as it gets totally drowned in oil. Didn't get this on my F200. Does anyone else suffer this on motors with the spark plug on the bottom ?

Too much oil in the mix

Too cold a plug being used

Fuel leaking in to cylinder when not used petrol evaporating leaving just the oil

No oil control ring on a two stroke as it has no oil in it

Pete

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Too much oil in the mix

Too cold a plug being used

Fuel leaking in to cylinder when not used petrol evaporating leaving just the oil

Oil mix is always precise with syringe, and to manufacturers spec. Plug is also correct spec and no sooty deposits or other signs that it is running too cold if removed after flight (and no problems running after warm-up, or flooding when starting).

Agree that it is just oil, after the petrol has evaporated - but it seems an excessive amount to drain down from crank case into combustion head. Fuel mix isn't leaking in from carb, and it only causes problems if the engine isn't run for more than 2 days (which means it needs draining and the plug cleaning before most flights at this time of year ....) :x

I guess it's spanner time for a detailed inspection ..... :lol:

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Too much oil in the mix

Too cold a plug being used

Fuel leaking in to cylinder when not used petrol evaporating leaving just the oil

Oil mix is always precise with syringe, and to manufacturers spec. Plug is also correct spec and no sooty deposits or other signs that it is running too cold if removed after flight (and no problems running after warm-up, or flooding when starting).

Agree that it is just oil, after the petrol has evaporated - but it seems an excessive amount to drain down from crank case into combustion head. Fuel mix isn't leaking in from carb, and it only causes problems if the engine isn't run for more than 2 days (which means it needs draining and the plug cleaning before most flights at this time of year ....) :x

I guess it's spanner time for a detailed inspection ..... :lol:

When you've finished flying for the day can you run the carb dry? it maybe when you put your motor in a warmer environment the pressure change in the tank is forcing fuel through the carb in to the engine.

What ratio are you running at 30-1? I run mine at 50-1 with fully synthetic and no problems.

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Too much oil in the mix

Too cold a plug being used

Fuel leaking in to cylinder when not used petrol evaporating leaving just the oil

Oil mix is always precise with syringe, and to manufacturers spec. Plug is also correct spec and no sooty deposits or other signs that it is running too cold if removed after flight (and no problems running after warm-up, or flooding when starting).

Agree that it is just oil, after the petrol has evaporated - but it seems an excessive amount to drain down from crank case into combustion head. Fuel mix isn't leaking in from carb, and it only causes problems if the engine isn't run for more than 2 days (which means it needs draining and the plug cleaning before most flights at this time of year ....) :x

I guess it's spanner time for a detailed inspection ..... :lol:

Hi Aquatix,

I was having similar issues with mine so I fitted a try break in the fuel line just before the carb so that no excess fuel is there. And also running it dry after disconnecting the dry break.

Barry

When you've finished flying for the day can you run the carb dry? it maybe when you put your motor in a warmer environment the pressure change in the tank is forcing fuel through the carb in to the engine.

What ratio are you running at 30-1? I run mine at 50-1 with fully synthetic and no problems.

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