Walkerjet F200 overheating

[acroal]

Help needed with Walkerjet F200 please.

Ok here's my problem - I have a walkerjet with a fly engines f200. It has burnt out 2 sets of piston rings in as many flights. I replaced the original cylinder and piston with new ones obtained direct from fly engines, these now look unserviceable. ( however I still have the old ones which look salvageable with a bit of polishing)

After some research I have found that the engine has the old cylinder head on it - the one which was causing overheating problems with so many F200's

The carb is the walbro 37c and the needles were set at 1 turn on the Lo and 1.5 turns on the Hi.

The mix was a 33/1 on Castrol semi synth motorbike oil.

Due to my size I had no need the cane the throttle to acheive a comfortable climb out.

The engine ran fine on the ground, it had 1-2 hours worth of gentle running in and was warmed up well before flying.

So here's my questions:

Is it worth buying the new oversize cylinder head? Will this more than likely sort the problem?

Would it be better to source a different engine? If so where from?

Has anyone got any other ideas as to why it is overheating?

Cheers

Alex

[aquatix]

My Walkerjet F200 (original cylinder head type) ran perfectly on 97-99 Octane fuel with 2% full synthetic oil - no overheating.

Are you using the 3 blade carbon prop or something else ? Prop design & pitch can effect the cooling airflow around the engine.

An air leak into the crank case could cause overheating, as could an exhaust leak, incorrect ignition timing or incorrect piston / ring clearance (tolerance).

Is there any wear to the Nicasil cylinder coating ?

Have you contacted Patricie at Walkerjet with photo's of the problem ? I found them very helpful (albeit slow with delivery) and parts were very cheap.

If you post some photo's I can compare them with the ones I took of my rebuil.d

[Farmer_Dave]

Help needed with Walkerjet F200 please.

Would it be better to source a different engine?

You're not the only person to have trouble with this engine. Gabe Cassidy might be able to help you. I sold mine whilst it had low hours (35) on the advice of a friend. Let me know if you need Gabe's email.

Some might say, if you need that much power, you'd be better off with a Simonini 200. I'd agree.

[padeakin]

The larger head will make a slight difference but I don't think it will solve the problem, if you still have the engine in pieces, check the cylinder ports, I once had an F200 that kept overheating, I took it to a specialist 2 Stroke engine re-builder, he told me the ports were not rounded off, and were catching the piston rings, he suggested I smooth them off with emery paper, I tried to do this but the Nikasol coating was too hard, so I told Patricie at Walkerjet and they sent me a new cylinder, the problem was solved.

A few years ago there was a problem when they first changed to digital ignition, the ignition advanced too much when on full revs this caused the engine to get too hot. A few of these were sold, when Walkerjet discovered the problem they offered too replace with the standard ignition, until they solved the problem, it is possible that you have one of these with the problem ignition system, how old is the motor?

I think you should send all information to Patricie at Walkerjet, and ask for their advice and help, they will know about all these problems, they are very helpful, but take a very long time to respond, it may take months to get the problem sorted, so if you can afford it buy another engine.

Paul D

[padeakin]

One option would be to ask Fly Engines if you can send it to them, to be rebuilt and fully tested

Paul

[acroal]

Hi Guys,

Thanks for the replies.

I'll try to get some pics posted as the engine is still in bits for the second time.

A bit of background here - I am in the process of maybe buying the motor off a friend - he bought it in July 09 and never flew it because of inexperience. He asked me to test fly it for him, which I did until it overheated. He got despondent with it and asked me if I wanted to buy it. I said I would after i had found the problem and had a good few flights on it. After stripping the engine I found that the piston and cylinder were marked (they will polish out tho) and the piston rings had failed.

I emailed Patricie and ordered a new piston, cylinder and complete gasket set. The engine was rebuilt and ground tests went fine. The second flight went pretty much like the first and the engine died after 15 minutes or so.

I am very tempted to fit a different engine as I don't need half of what the f200 can provide ( I had a RAD MXL a few years ago and had many good flights on it albeit it was a pain to get off the ground and the climb out was slow) - Flat Top Dave I think you mis - read that part!!

What other engines will fit that frame? - I have good engineering contacts for any mods that might be needed.

@ Paul - I don't know enough about the history of the engine to know what ignition system it has. All I know is the frame is in perfect condition and the engine looks like it hasn't done many hours - maybe the previous owner saw these problems coming.

Cheers

Alex

[Mariner]

I have had 2 Walkerjet F 200 since 2009. Still flying my second one. Never had anything wrong with them. Never fuel lower than 99 Octane and never oil different from Motul 800 2t 100%synthetic.