rocketron Posted April 18, 2006 Report Share Posted April 18, 2006 Hi all I am the proud owner of a new 06 Scorpa,I had an 02 one for a year and I just love em but have a carburation prob with my new one.... Bike starts ok,sounds dead flat on the choke and have to get the choke off fast as it will bog the engine but once choke is in she is fine.After ten mins or so it seems fuel starved,pinks a bit,then goes really dead as if no fuel getting in.If I can manage to keep it going it seems to clear and runs well for rest of the day.Have had carb off,no problems in there,have tried running with tank breather off,no better! I am running on Hi Octane fuel,100:1 Castrol 747 and am totally mystified by this problem.It only seems to happen once per outing.It is definitely not water in the carb or air filter as i did all the carb checking etc.. before washing the bike. Any ideas? What is best setting for mixture screw? This is first time I've used 747 oil at 100:1 mix.As it is a new engine I hope it isnt partially seizing? Ta for any ideas!! Ron Quote Link to comment Share on other sites More sharing options...
neonsurge Posted April 18, 2006 Report Share Posted April 18, 2006 100:1 sounds awfully lean, especially when you're still running in the engine. Dunno what's recommended for the TYZ engine but it's usual to run you mixture more like 60:1 when new, moving to 75-80:1 when everything's properly bedded in. Quote Link to comment Share on other sites More sharing options...
jools Posted April 18, 2006 Report Share Posted April 18, 2006 It does the exact same on my 06 when starting so it presume thats normal? and have had the same problem as you but found it to be a jitsie airfilter that i ran, found it would sound like it was starving then die. ran it with the normal airfilter and has'nt done it. run it on 80ml oil to 5litres of optimax.... other than that dunno. Quote Link to comment Share on other sites More sharing options...
boofont Posted April 18, 2006 Report Share Posted April 18, 2006 I run 75:1 with 747, normal unleaded petrol. No probs from my 03. Quote Link to comment Share on other sites More sharing options...
martinm Posted April 18, 2006 Report Share Posted April 18, 2006 100:1 sounds awfully lean, especially when you're still running in the engine. Dunno what's recommended for the TYZ engine but it's usual to run you mixture more like 60:1 when new, moving to 75-80:1 when everything's properly bedded in. <{POST_SNAPBACK}> Not wishing to be picky here, but theroetically 100:1 will make a bike run rich not lean!!!! Reason being that........ lean or rich mixture refers to the air/fuel mixture not petrol/oil ratio. A high petrol to oil ratio (eg 100:1) flows through the carb quicker than a more viscous (say 50:1) mixture. Therefore the bike is getting more fuel than air so runs rich. What the oil does is lubricate the top end, and to answer the post, I would think the motor is running way too hot. Stick some more oil in the mix before it wrecks the top end. Lesson over Martin Quote Link to comment Share on other sites More sharing options...
348mate Posted April 18, 2006 Report Share Posted April 18, 2006 Reason being that........ lean or rich mixture refers to the air/fuel mixture not petrol/oil ratio. I will second the above . Also 100/1 too little oil for any 2 st. in my humble opinion. S.m. Quote Link to comment Share on other sites More sharing options...
rocketron Posted April 18, 2006 Author Report Share Posted April 18, 2006 Yep guys,kind of agree.First step is to change premix to around 75:1.I was running the 100:1 mix in my old Scorpa with no bother but it was a well bedded in engine.The odd thing is that the 06 bike runs fine once it gets over the fuel starvation thing,but that could just be the barrel heating up slower than the piston and rings.... What you all running in terms of mixture screw settings? 1 3/4 turns out?? Ta again Ron Quote Link to comment Share on other sites More sharing options...
scorpa-usa Posted April 19, 2006 Report Share Posted April 19, 2006 80:1 should be the correct amount of oil. If everything is stock on your bike and your sure the carb is absolutely clean then I would be concerned about the bike running too hot. Symtoms of pinging and stress to keep running described may indicate a hot engine which may be caused by a poor thermo switch or lack of coolant. Quote Link to comment Share on other sites More sharing options...
downunder Posted April 19, 2006 Report Share Posted April 19, 2006 Hi Guys I don't know about the fuel starving bit but my new 06 likes a good clear out once it is off the choke. It always starts on the second kick from cold with full choke, then I open the choke and tickle the throttle for a bit to keep it running until warm. If you open the throttle before it has started to warm up it will die instantly. On the other hand, if you leave the choke on too long you can bet your grandma's undies that it will fuel up and run like a lawn mower until cleared out. I'm running a 140 main jet so it is leaner than stock but it still likes to get a good rev out through the gears to clear any excess fuel out of the bottom end. The mixture screw has me beat on this bike though.... it seems to run ok anywhere between 1/2 a turn and about 4 turns out??????? Now that the motor has had a few hours I have gone down from 50:1 to 70:1 Motul 800 but I might still try a leaner main sometime in the future. This info may not be too much use to you as I am riding the "SY250 Racing" not the UK model that comes with a tow hitch for plowing fields Quote Link to comment Share on other sites More sharing options...
jools Posted April 19, 2006 Report Share Posted April 19, 2006 try phoning Birketts coz they are very helpful, or take it back to dealer because the bike 99.99999% spot on from the factory. does sound like its getting hot. Quote Link to comment Share on other sites More sharing options...
bikerdude2006fr Posted April 19, 2006 Report Share Posted April 19, 2006 Hmmmm the dying souinds like what the scorpa 4t that my club lends me does! it will be riding fine, i will go and so something then let of the engine just so its ticking over, round a turn or something and sometimes the engine just dies wil the clutch fully in ect!! its wierd, thats with a scorpa 125 4t long ride i think it is, and 05 i believe Quote Link to comment Share on other sites More sharing options...
downunder Posted April 20, 2006 Report Share Posted April 20, 2006 Bikerdude My TY-S175 was a bit like that until I changed the main and pilot jets (see Birketts webpage for details) the other thing with the little 4t's is they run really strange when you are getting low on fuel, even though there seems to be enough in the tank they tend to cough and splutter well before they actually run out of gas. The other thing that makes them do funny things is having the wrong float level setting (I think Birketts have that covered to) Quote Link to comment Share on other sites More sharing options...
bikerdude2006fr Posted April 20, 2006 Report Share Posted April 20, 2006 (edited) Damn thats a bit much for me(not to much motorbike mechanics experience) to be looking into for a bike thet i borrow Wouldnt want to be doing things like that to it Oh well if you hear it going you just have to give the throttle a blip so i just have to be ready Edited April 20, 2006 by bikerdude2006fr Quote Link to comment Share on other sites More sharing options...
bikerdude2006fr Posted May 6, 2006 Report Share Posted May 6, 2006 Hmmmm the dying souinds like what the scorpa 4t that my club lends me does! it will be riding fine, i will go and so something then let of the engine just so its ticking over, round a turn or something and sometimes the engine just dies wil the clutch fully in ect!! its wierd, thats with a scorpa 125 4t long ride i think it is, and 05 i believe <{POST_SNAPBACK}> YAY!! Found my problem The choke cable was/is just getting pulled a very small bit when the bars are turned all the way to the right! I think its because the breather has been routed under the cables so is restricting space. So next time i got it im gonna reroute the breather :)Then hopefully my problem will be solved Quote Link to comment Share on other sites More sharing options...
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