Guest Posted October 23, 2008 Share Posted October 23, 2008 Why would the EGT go through the roof?? (unless your mixture is out) I think you read EGT when the post said CHT, Pete. Quote Link to comment Share on other sites More sharing options...
pete_b Posted October 23, 2008 Share Posted October 23, 2008 Why would the EGT go through the roof?? (unless your mixture is out) I think you read EGT when the post said CHT, Pete. Sorry Pete b Quote Link to comment Share on other sites More sharing options...
Guest Posted October 23, 2008 Share Posted October 23, 2008 Just order a blank hub and drill it/get it drilled to fit your motor. The blade root thickness on the GSC won't allow a PCD significantly less than 75mm when using 4 bolt holes at 90 degree intervals. To achieve this the diameter of the blade roots would have to be reduced which would mean a new milling set up. This is not viable as most of GSC's business is to the States where the Top 80, Ros and HE are not so popular but the Black Devil with its 6 bolt 75mm PCD is, so that is what they concentrate on. We have looked into modifying the existing hub but it doesn't give enough material to take the stresses involved. Consequently the only solution would seem to be an adapter plate. I believe Phil may have made one up himself. Quote Link to comment Share on other sites More sharing options...
bathboy Posted October 23, 2008 Share Posted October 23, 2008 The blade root thickness on the GSC won't allow a PCD significantly less than 75mm when using 4 bolt holes at 90 degree intervals. To achieve this the diameter of the blade roots would have to be reduced which would mean a new milling set up. This is not viable as most of GSC's business is to the States where the Top 80, Ros and HE are not so popular but the Black Devil with its 6 bolt 75mm PCD is, so that is what they concentrate on. We have looked into modifying the existing hub but it doesn't give enough material to take the stresses involved. Consequently the only solution would seem to be an adapter plate. I believe Phil may have made one up himself. Could I use the same Black Devil GSC hub for longer two or shorter three bladed props? I'm looking to be able to convert my Parajet 3 blade Compact to a 2 blade Macro and back. The Compact for snug in the car with family for holidays the Macro for some longer distance flying. I hear a rumour they've done that Cheer Paul P.S. Yes, I still want to keep the same car and family! Quote Link to comment Share on other sites More sharing options...
pete_b Posted October 23, 2008 Share Posted October 23, 2008 The blade root thickness on the GSC won't allow a PCD significantly less than 75mm when using 4 bolt holes at 90 degree intervals. To achieve this the diameter of the blade roots would have to be reduced which would mean a new milling set up. This is not viable as most of GSC's business is to the States where the Top 80, Ros and HE are not so popular but the Black Devil with its 6 bolt 75mm PCD is, so that is what they concentrate on. We have looked into modifying the existing hub but it doesn't give enough material to take the stresses involved. Consequently the only solution would seem to be an adapter plate. I believe Phil may have made one up himself. Could I use the same Black Devil GSC hub for longer two or shorter three bladed props? I'm looking to be able to convert my Parajet 3 blade Compact to a 2 blade Macro and back. The Compact for snug in the car with family for holidays the Macro for some longer distance flying. I hear a rumour they've done that Cheer Paul P.S. Yes, I still want to keep the same car and family! The two blade and three blade use different hubs so gat a three blade hub and use on both BUT you would need 6 blades (three short/3 long)instead of five Pete b Quote Link to comment Share on other sites More sharing options...
Guest Posted October 23, 2008 Share Posted October 23, 2008 The machined aluminium hubs are dirt cheap. It would be very cheap to buy a 3 blade prop and ask Rick to supply an additional 2 blade hub. Paul, as Pete says surely you would want different blade lengths for the compact and the macro. The same hub can be used for differing length blades however the blade sets need to be matched so that they balance. Each blade has a number so if you need a single replacement you can ask for an individual replacement once you have given Rick the number. These props are very cheap. I was buying the 2 blade complete set for about £130 delivered to a US hotel which I would then bring back under my duty free allowance last year. No more accepting somebody elses definition of what the right pitch was for my machine; just one prop with perfect pitch. Quote Link to comment Share on other sites More sharing options...
Jacko Posted October 24, 2008 Share Posted October 24, 2008 Have you checked that the fuel is getting to the mixing chamber at high revs - it may be a stuck non return valve in the carb body? Unscrew the H adjuster and gently blow into the hole using a piece of tube. You should be able to tell if it is clear or not. Jacko Quote Link to comment Share on other sites More sharing options...
dantheman Posted October 24, 2008 Share Posted October 24, 2008 Have had the carb totally stripped out and blown it through with compressed air, clean as a whistle. Starts first pull as usual, runs like a dream until WOT. I'm going to wait until I get my old prop back before doing anything else - at least I know the carb is fully overhauled and good for many hours to come. May have to send this prop back to Paul Kilburn, I hope he's ok about that. Quote Link to comment Share on other sites More sharing options...
Guest Posted October 24, 2008 Share Posted October 24, 2008 Well he bloomin' well ought to take it back as 36" pitch is outrageous for an R120. I would have thought 30" was already slightly on the high side. The R80 on the same diameter runs a 22" pitch. Don't do any more carb fiddling until you have a correctly pitch prop fitted. There is nothing wrong with the carb/paramotor, it's the new prop at fault. This problem is far more common than most people think and everyone understandably thinks it's a carburation issue when it isn't. Quote Link to comment Share on other sites More sharing options...
Phil_P Posted October 24, 2008 Share Posted October 24, 2008 An overpitched prop will really hold your revs down. Quote Link to comment Share on other sites More sharing options...
dantheman Posted November 9, 2008 Share Posted November 9, 2008 Just got me a genuine H&E prop from ebay and motor now runs fine so definately a prop pitch issue at least I know my way round two stroke carbs now Quote Link to comment Share on other sites More sharing options...
Guest Posted November 9, 2008 Share Posted November 9, 2008 That is Amazing! It so seemed like the carb man! Amazing! SW Quote Link to comment Share on other sites More sharing options...
dantheman Posted November 11, 2008 Share Posted November 11, 2008 Had a chat with Paul at Manchester Paragliders and it's just the wrong prop for my machine, there was a bit of confusion with the P11 & P12 props and it looks as though I actually need the P11, the P12 is for the H&E R220 hence the difference in pitch and he's updating the website as we speak. Anyway all sorted now and can definately reccomend those props in terms of quality, balance and Paul for price, speed of delivery and customer service. Quote Link to comment Share on other sites More sharing options...
dantheman Posted November 22, 2008 Share Posted November 22, 2008 Just had an email from Pierre at H&E - I asked if you needed to adjust the carb between 115 and 125cm props. Hello Dan, You can run it with a 115cm prop without any problem as long as it is a 45*34R. This propeller should not require any change of carburetion (as far as I know). The only effect is going to be a loss of power of about 3-4 kilos of thrust. You should have at 9500 rpm around 54 kilos of thrust. Thanks and best regards, Pierre J. Diet Quote Link to comment Share on other sites More sharing options...
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