trickedcarbine Posted September 13, 2015 Report Share Posted September 13, 2015 Get 23-24cc domes if you wanna be on pump. You bought and paid for 110. Why go muddying it up with 91 blend? Just run it straight for now and pay the few bucks for the right domes for what you want. Quote Link to comment Share on other sites More sharing options...
pablopab50 Posted September 13, 2015 Author Report Share Posted September 13, 2015 Get 23-24cc domes if you wanna be on pump. You bought and paid for 110. Why go muddying it up with 91 blend? Just run it straight for now and pay the few bucks for the right domes for what you want. I was running pump 91 and some octane booster on my stock cylinder with 160 PSI. Which dome would go down to 160 with a 68 bore? Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted September 13, 2015 Report Share Posted September 13, 2015 < giving up. 2 Quote Link to comment Share on other sites More sharing options...
pablopab50 Posted September 13, 2015 Author Report Share Posted September 13, 2015 < giving up. Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted September 13, 2015 Report Share Posted September 13, 2015 You are being handed a solution, yet keep looking for some kind of loophole. If you don't know, yet ask people who do, why dance around what needs to be done? Why half ass it? Why spend thousands of dollars to risk ruining it when a few changes could make all the difference between an average running motor that comes apart all the time, or having a motor that runs at the top of it's level and is reliable? You're asking folks for answers, but you are just gonna do what you feel is right any way. You wanna buy 22cc domes. What will that put your compression at? Will it be what you need I to be? What kind of compression do you need a cub with even mild exhaust work to show on a gauge to be able to safely run 91 with or with out any timing? Even when you get that gauge to show the magic 150 psi on a cub, is your uncorrected compression ratio appropriate for such low octane? Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted September 13, 2015 Report Share Posted September 13, 2015 If you can figure out the answers to the second half of that, you will know exactly what you need to do. Quote Link to comment Share on other sites More sharing options...
Dunatic619 Posted September 13, 2015 Report Share Posted September 13, 2015 @ Tricked: best explanation of pre-detonation I've ever read! @OP: Cubs are a different beast than stock cylinder engines. Either wait for domes, or run the race, straight, until domes arrive. I understand wanting to run the quad on the cheapest petrol possible, but sometimes doing things the cheap way end up costing more in the long run. Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted September 13, 2015 Report Share Posted September 13, 2015 Pre detonation isn't a fucking word! Quote Link to comment Share on other sites More sharing options...
pablopab50 Posted September 13, 2015 Author Report Share Posted September 13, 2015 You are being handed a solution, yet keep looking for some kind of loophole. If you don't know, yet ask people who do, why dance around what needs to be done? Why half ass it? Why spend thousands of dollars to risk ruining it when a few changes could make all the difference between an average running motor that comes apart all the time, or having a motor that runs at the top of it's level and is reliable? You're asking folks for answers, but you are just gonna do what you feel is right any way. You wanna buy 22cc domes. What will that put your compression at? Will it be what you need I to be? What kind of compression do you need a cub with even mild exhaust work to show on a gauge to be able to safely run 91 with or with out any timing? Even when you get that gauge to show the magic 150 psi on a cub, is your uncorrected compression ratio appropriate for such low octane? Yes you are right. I might just run pure race gas untill I get bigger domes. You remind me of my buddy who had huge piston slap and just redone the rings instead of having the cylinders rebored. He went cheap way and it blew a month later. Jeff at F.A.S.T. told me with 22s I could run pump. Again let's say I reach 160 PSI. I could still add some octane booster to raise it up to 100 right? I just read that every motor are different and a 160 PSI on a stocker is different than on a cub. So your 150 PSI magic number kind of makes sense. But isn't 150 PSI on a big motor such as the cub really low? Am I being a bitch or a poor ass boy and should I just open my damn wallet and spend the extra hundreds the cub needs in gas? Is it okay to run pump gas on a cub first of all? lol... If you saw the pictures in the second or third page of this thread, you can see it's ported. So, do the cylinders as they are require higher octane gas to perform well? I also just don't want to have to replace the rings 2 times per season. I'm not into drag like I mentioned previously and I don't care if I loose 10 HP. The motor probably already have at least 80 horses. Gotta love the struggle of built 2 strokes Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted September 13, 2015 Report Share Posted September 13, 2015 Octane booster doesn't work! 1 Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted September 13, 2015 Report Share Posted September 13, 2015 Yes you are right. I might just run pure race gas untill I get bigger domes. You remind me of my buddy who had huge piston slap and just redone the rings instead of having the cylinders rebored. He went cheap way and it blew a month later. Jeff at F.A.S.T. told me with 22s I could run pump. Again let's say I reach 160 PSI. I could still add some octane booster to raise it up to 100 right? (Why are you wanting to put booster in the thing. It's junk. Not good for a two stroke. If you want to buy the right domes for pump, why not make sure they are for pump and not for pump and "booster"?) I just read that every motor are different and a 160 PSI on a stocker is different than on a cub. So your 150 PSI magic number kind of makes sense. But isn't 150 PSI on a big motor such as the cub really low? (150psi cranking compression just kind of a rough gauge to see where a motor falls. Typically you need to calculate a motor's actual compression to know fuel type but cranking can get you close. But mind you this, when you have a cub cylinder the exhaust is typically letting a lot of volume by so the number will look low on a gauge when you kick it. Now actually fire the motor and the piston is moving fast enough to trap most of that volume and compressing far more then a gauge shows. And no, that wouldn't be low. There are a lot of drag cubs on alky only showing 160-165 psi when you kick them. They're like 13:1ish motors. There are even cubs that show 150 on a gauge but still need lots of octane as the exhaust is kinda gnarly) Am I being a bitch or a poor ass boy and should I just open my damn wallet and spend the extra hundreds the cub needs in gas? Is it okay to run pump gas on a cub first of all? lol... If you saw the pictures in the second or third page of this thread, you can see it's ported. So, do the cylinders as they are require higher octane gas to perform well? I also just don't want to have to replace the rings 2 times per season. I'm not into drag like I mentioned previously and I don't care if I loose 10 HP. The motor probably already have at least 80 horses. Gotta love the struggle of built 2 strokes (If you aren't worried about losing a touch of performance, make the dome change for a solid reliable compression range with out wanting to add some 10 dollar gimmick in the gas.) Quote Link to comment Share on other sites More sharing options...
sleeper06 Posted September 13, 2015 Report Share Posted September 13, 2015 At the end of the day most race fuels are chemically diffrent than fuels outta the pump and most of us arnt chemists , I'm with tricked use straight 110 on that set up. Throw a 24 cc dome in it run 91 all day but give up 6-8hp or pay a lil more for fuel Quote Link to comment Share on other sites More sharing options...
Dunatic619 Posted September 13, 2015 Report Share Posted September 13, 2015 Pre detonation isn't a fucking word!. I didn't type that. Dos Equis did! Quote Link to comment Share on other sites More sharing options...
pablopab50 Posted September 13, 2015 Author Report Share Posted September 13, 2015 At the end of the day most race fuels are chemically diffrent than fuels outta the pump and most of us arnt chemists , I'm with tricked use straight 110 on that set up. Throw a 24 cc dome in it run 91 all day but give up 6-8hp or pay a lil more for fuel Correct. I wouldn't say a little more lol. I paid my 5US gal for like 115 CAD tax included which is like 90 USD. Here 5US gal at the 91 pump would be about 20 USD. With a cub it's a complete tank each ride... So it's pricey as hell. Quote Link to comment Share on other sites More sharing options...
pablopab50 Posted September 13, 2015 Author Report Share Posted September 13, 2015 So you guys recommend either 23cc or 24cc Quote Link to comment Share on other sites More sharing options...
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