cymaz Posted February 3, 2014 Share Posted February 3, 2014 After not starting my G38 for several months I decided to run it up on Sunday as there was a 12 hour break in the wind and rain. It took an age to start. There was good spark and fuel dripping from the carb. The fuel was not fresh - must admit. Top end was good and held steady, low needle was a pig. It was very very sensitive,1/16 of a turn was too much! And I could not get rid of the mid range 4 stroking on the LSN without ruining the starting and idle. It took an age to start, in the end I had to put a starter to it- that is a serious crime in my book. There is a WT338 Walbro carb fitted with a velocity stack. Now, asking around it may be that the crankcase seals are leaking letting in air. I have ordered some spares from Glens Models and some new carb gaskets and insulator block. Does anyone know how hard it is to change the crankcase seals on a G38?? If it not too difficult then would any other G38 owners like a thread? Quote Link to comment Share on other sites More sharing options...
Ultymate Posted February 3, 2014 Share Posted February 3, 2014 Did you try some fresh fuel in it ? Quote Link to comment Share on other sites More sharing options...
cymaz Posted February 3, 2014 Author Share Posted February 3, 2014 Had some fuel mix in a can that was about 4 months old. Quote Link to comment Share on other sites More sharing options...
Ultymate Posted February 3, 2014 Share Posted February 3, 2014 Unleaded petrol can deteriorate fairly quickly I'd be inclined to try a fresh brew before getting in too deep with repairs. Sometimes first runs/starts of the season can be difficult due to residue oil running down into the spark plug over a lengthy period particularly if the engine is mounted inverted which most petrol jobs are P.S. I'm lucky with my fuel mix as I use it in my chainsaws over the winter so I never have a brew go stale Edited By Ultymate on 03/02/2014 10:35:53 Quote Link to comment Share on other sites More sharing options...
cymaz Posted February 3, 2014 Author Share Posted February 3, 2014 Thankyou. I ran out of time Sunday so more investigation done today. Knowing that the engine doesn't like air leaks I decided to take the carb off Checked the first gasket between the carb and the nylon block..there was a weak spot in the gasket-a tear that had begun to make its way across but not gone all the way. So that is one possibility. Ordered some new gaskets, nylon block,seals and bolts from HERE Look forward to repairing the engine Quote Link to comment Share on other sites More sharing options...
cymaz Posted March 23, 2014 Author Share Posted March 23, 2014 Right update, after replacing all the pipe work, new felt clunk, 2 new carb gaskets, new nylon carb spacer all sealed with copper high temp gasket sealer, it has done the trick . Primed up well,carb choke closed and coughed with ignition on. Opened the choke and two light flicks later sprang right into life. Well pleased. Still chucks out a bit of oil but I'll live with that. I will get a different prop or two for a trial. Thanks for all the help. I used Castrol Power 1 Racing fully synthetic oil. Got 1650-1700 on idle and 7200-7300 WOT. 32:1 Ratio mix. Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted March 23, 2014 Share Posted March 23, 2014 Good reliable motors Zenoah Cymaz glad your sorted Quote Link to comment Share on other sites More sharing options...
cymaz Posted March 23, 2014 Author Share Posted March 23, 2014 Ta, thought I would post the results in case someone else had a Zenoah with a running problem. Quote Link to comment Share on other sites More sharing options...
reg shaw Posted March 23, 2014 Share Posted March 23, 2014 Its chucking out oil because there is too much oil going in. All of my Zenoahs run on 50 to 1mix, on a new one I still use 50 to 1 but don't rev its knackers off for long bursts. What was the clunk Cymaz? If it was a felt job then a lay up with tank empty makes the clunk shed its fibres. These fibres find their way through most filters and block the carb at that round (its about 8mm) gauze filter under the carb side plate. This filter can be removed with care, though the manufacturers say don't apparently. With a pin it can be flicked out and back flushed. I've found this a few times over the years and always (try to) leave fuel on the tanks. Best option by far though is to fly the blighters all year round!! Glad you got it sorted though, Ian. Quote Link to comment Share on other sites More sharing options...
cymaz Posted March 23, 2014 Author Share Posted March 23, 2014 I think I will stick to the recommended 32:1 mix. Only because my new Evolution 33gx uses the same ratio. So I only need one petrol can. Ian, there is a felt clunk. I did clean it out and reset the needle float valve with a gauge plate- it was set wrong. Lazy ain't I Quote Link to comment Share on other sites More sharing options...
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