dadof2 Posted March 25, 2017 Report Share Posted March 25, 2017 In general do not use avgas in a trials engine. It has additives an characteristics a trials engine does not need and in some cases may be detrimental to the running of a trials engine. For same reasons avoid high octane race gas. Unleaded 95 to 98 Octane should be fine even if it contains ethanol. Ethanol reduces power but so little you won.t notice. Ethanol does not affect running on the 4RT so long as its not left in the tank too long. The 4RT ECU can't "sort things out" because it has neither knock nor Lambda sensors. Leaded fuel should not be used because modern spark plugs are not designed to withstand lead. 3 Quote Link to comment Share on other sites More sharing options...
heffergm Posted March 26, 2017 Report Share Posted March 26, 2017 (edited) Doesn't the 4rt have a big 'No Lead/Pb' sticker on the tank? VP110 is leaded, as is Avgas (100LL). Edited March 26, 2017 by heffergm 1 Quote Link to comment Share on other sites More sharing options...
paul7 Posted March 26, 2017 Report Share Posted March 26, 2017 31 minutes ago, heffergm said: Doesn't the 4rt have a big 'No Lead/Pb' sticker on the tank? VP110 is leaded, as is Avgas (100LL). yep, also, manual says unleaded 91 0ctane or higher. Quote Link to comment Share on other sites More sharing options...
copemech Posted March 27, 2017 Report Share Posted March 27, 2017 On 3/25/2017 at 6:53 PM, dadof2 said: In general do not use avgas in a trials engine. It has additives an characteristics a trials engine does not need and in some cases may be detrimental to the running of a trials engine. For same reasons avoid high octane race gas. Unleaded 95 to 98 Octane should be fine even if it contains ethanol. Ethanol reduces power but so little you won.t notice. Ethanol does not affect running on the 4RT so long as its not left in the tank too long. Leaded fuel should not be used because modern spark plugs are not designed to withstand lead. It never ceases to amaze me how some of this information is derived. Quote Link to comment Share on other sites More sharing options...
heffergm Posted March 27, 2017 Report Share Posted March 27, 2017 If by 'derived' you mean 'made up', I'm with you 1 Quote Link to comment Share on other sites More sharing options...
djr_austin Posted March 31, 2017 Author Report Share Posted March 31, 2017 On 3/25/2017 at 11:50 AM, fxstbi said: djr_austin, I live just east of Austin and I remember talking with you at last months trials in city park. I have a Beta 4t and a Montesa and I run both on avgas. They run great and I don't have any complaints running it. I do know the you can get 93 with no ethanol in Austin, a friend of mine runs it in his 300 RT and gets it somewhere in Austin. Avgas is available at most any small airport, I get mine in Smithville for 3.95 a gallon. Right on. Ask your friend where he gets it. I'm back at the pump getting 93 with 10% ethanol and will gladly switch - 93, unleaded, 0%, gas station, in Austin - peachy! Thanks! Quote Link to comment Share on other sites More sharing options...
djr_austin Posted March 31, 2017 Author Report Share Posted March 31, 2017 On 3/25/2017 at 6:03 PM, bbk said: I was told on Avation fuel they mix something for high altitude to keep fuel from gelling or something like that i used in my sweet bike at the time was told i shouldn't .VP fuel staion carry 101 octane at the pump. Alot of motorcycle dealers carry race fuel in there shops too. But getting back to your problem doesnt sound like its the type of fuel. What year is the bike? whats the plug look like? how about the tail pipe clean or sooty? I did have an after market muffler on mine that the packing came loose and caused the bike to do as your describing come to think of it. Its a 2017 4RT - pipe / plug fine - only ran two tanks through it - dropped the race gas and its back purring like a pussy :-) Quote Link to comment Share on other sites More sharing options...
sportsawyer Posted March 31, 2017 Report Share Posted March 31, 2017 To find ethanol free gas in the USA & Canada, see: http://pure-gas.org/ 1 Quote Link to comment Share on other sites More sharing options...
guys Posted March 31, 2017 Report Share Posted March 31, 2017 On 25-3-2017 at 3:30 PM, pschrauber said: In my personal experience I like Aspen gas very much invented for forest machinery and based on Alcylate instead on oil. It burns without soot and without smell can be stored for years comes with 95, 98 or 101 octane but it is expensive. For a clean exhaust and engine, your health and the environment a real good fuel. Yep. I use the Aspen 4 (95) fuel regularly, and my 4RT runs fine with it. (It's also very useful in generators and other machines that aren't used regularly, as it won't deteriorate over time) 1 Quote Link to comment Share on other sites More sharing options...
fxstbi Posted April 1, 2017 Report Share Posted April 1, 2017 On 3/30/2017 at 7:48 PM, djr_austin said: Right on. Ask your friend where he gets it. I'm back at the pump getting 93 with 10% ethanol and will gladly switch - 93, unleaded, 0%, gas station, in Austin - peachy! Thanks! As stated above go to puregas.org, Texas and start searching the cities nearest you. I would suggest you call first to make sure they have it. I was incorrect about my friend getting his gas in Austin, he got it in Fredericksburg. He got two five gallon metal cans and drove there and picked it up. 1:20 minutes away from Austin. Quote Link to comment Share on other sites More sharing options...
dadof2 Posted April 2, 2017 Report Share Posted April 2, 2017 On 27/03/2017 at 5:21 AM, copemech said: It never ceases to amaze me how some of this information is derived. No need for yours or heffgms sarcasm, I spent many years in the oil / chemicals industry and several more where research into and manufacture of biofuels was carried out. What I posted is common knowledge in these places. I do not know the exact situation in the USA but in the UK the composition of pump fuels both petrol and diesel is varied between winter and summer, the adjustments to avgas to allow for low temperatures and pressures is far greater. Aero engines are designed for steady speed running and so is the fuel. No point in using higher octane race gas unless your compression ratio has been increased to benefit and appropriate adjustments made to ignition timing. Stick it in a standard engine and you will loose performance and waste money and possibly overheat the exhaust components. Lead fouling Insulator nose covered in places with brown/yellow glazing, which can have a greenish color. Cause: Lead additives in fuel. Glazing results from high engine loading after extended part-load operation. Effects: At high loads, the glazing becomes conductive and causes misfiring. Remedy: Fit new spark plugs since cleaning the old one is pointless. 1. 2. 3. 4. Pronounced lead fouling Insulator nose covered in places with thick brown/yellow glazing, which can have a greenish color. Cause: Lead additives in fuel. Glazing results from high engine loading after extended partload operation. Effects: At high loads the glazing becomes conductive and causes misfiring. Remedy: Fit new spark plug The above advise is from Bosch. Lead fouling resistance is no longer a criteria in spark plug manufacture and even less extreme results than the above greatly shorten plug life. Hence as others have posted the "no leaded fuel" stickers on their bikes. 5 Quote Link to comment Share on other sites More sharing options...
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