ridgrunr Posted March 18, 2013 Report Share Posted March 18, 2013 (edited) Been doing some jetting to see if I can help end the stalled engine 5's. I've never really ran it full throttle before to check the main jet spark plug color, but have noticed the revs go a little flat right at the top, as if there is a rev limiter. Tried rich, tried lean and it doesn't make any difference. Bike runs great, gut goes flat right at the top of the R's. Anyone expereinced this? Now I'm wondering if other makes have a rev limiter? Edited March 18, 2013 by ridgrunr Quote Link to comment Share on other sites More sharing options...
laser1 Posted March 18, 2013 Report Share Posted March 18, 2013 Have you cleaned your mid box and silencer? Doubt there is a rev limiter on a SY - but im no expert on them. Quote Link to comment Share on other sites More sharing options...
0007 Posted March 18, 2013 Report Share Posted March 18, 2013 (edited) Most 2 strokes don't have a rev limiter If it did have one it would produce an ignition misfire which would then cause an after fire in the muffler Very hard to miss It's probably a characteristic of the pipe design and the ignition timing, in a way, it is a rev limiter but that's how they do it on pretty much all 2 strokes Edited March 18, 2013 by 0007 Quote Link to comment Share on other sites More sharing options...
breagh Posted March 18, 2013 Report Share Posted March 18, 2013 Try it with the mudguard off,the filter set up is quite restrictive. Quote Link to comment Share on other sites More sharing options...
baldilocks Posted March 18, 2013 Report Share Posted March 18, 2013 When I had a 2006 model i thought it had one but i cant tell you for certain. If you have been sitting in a queue for a while and try and clean the motor out before a big climb or step it wont rev out it seems restricted. Yet under load going up a hill it revved higher than any other bike I have owned. I suppose under no load with the clutch in its actually revving higher so its maybe hitting the limiter ? also best bike ever made for steps, rear suspension just soaks them up. Quote Link to comment Share on other sites More sharing options...
ridgrunr Posted March 21, 2013 Author Report Share Posted March 21, 2013 Looks like there isn't a rev limiter. But after trying every jetting possibility I could think of (man I'm becoming an expert at getting to that carb! And yes that carb is crystal clean!) I couldn't find any combination that would get rid of that top end flat spot. Bike runs perfectly everywhere else. So I went on a web search and eventually found a site that explained what could be expected to be found with most intake issues and how to diagnose and correct them. In one, he described my issue perfectly, then said the problem was most likely an intake reed issue, the one thing I hadn't checked. That made sense to me, so I ordered a set of Boyesen Trials specific reeds. http://boyesen.com/power-reeds-358.html. They probably won't make it here in time for the meet this weekend, but should be here in time to get them in for the 5 Miles of Hell ride. I'll let you know. Quote Link to comment Share on other sites More sharing options...
ridgrunr Posted March 30, 2013 Author Report Share Posted March 30, 2013 Well, after trying everything I could think of in an effort to get rid of that top end flat spot, I finally replaced the reeds. I was suprised to discover the stock reeds were fiber and not steel like I was expecting. But, they were chipped. Two of the petals had chips on the top. So I put in the Boyesen Power reeds, and just like that the top end flat spot was gone. Revs quicker and smoother too. Well worth the $39 they cost me. Think I'm all ready for the Five Miles of Hell next week. Now if I could only figure out a way to shed thirty years! Quote Link to comment Share on other sites More sharing options...
bigmike1961 Posted March 31, 2013 Report Share Posted March 31, 2013 http://boyesen.com/p...reeds-358.html. That link didn't work for me Was this what you fitted? http://boyesen.com/vaf/product/list/?category=%3F&make=70&model=1502&option=1513&year=1488 (the first one - on the left?) Quote Link to comment Share on other sites More sharing options...
ridgrunr Posted March 31, 2013 Author Report Share Posted March 31, 2013 Yup, them's the ones, the power reed on the left. Things came in like two days too! Quote Link to comment Share on other sites More sharing options...
copemech Posted April 3, 2013 Report Share Posted April 3, 2013 Good work Ridg! You may fallin love again! Quote Link to comment Share on other sites More sharing options...
axulsuv Posted April 5, 2013 Report Share Posted April 5, 2013 That's a great tip to log in the old memory banks ! And when you figure out the shedding 30 year thing , let me know ! Heck I'd settle fo 20 !! Glenn Quote Link to comment Share on other sites More sharing options...
ridgrunr Posted April 8, 2013 Author Report Share Posted April 8, 2013 (edited) Ok, rode Utah's 5 Miles of Hell yesterday. http://www.utahtrial.../5moh/5moh.html What a great day! Three of us went across, my Scorpa, Chris on his Gaser and Jay on his YZ250. Wondered how the YZ would do, but he did OK. He worked a lot harder than we did on the Trials bikes, but he was prepared, as was his bike! A broken shifter lever on the Gasser was our only issue. The new Boyesen reeds worked great in the SY, but they did make it run a little rich in the mid range and it used a little more gas than usual. I could hear it popping more on the low end too, so I dropped the needle a notch this morning. Other than that, the bike ran great all day. This was the Scorpa's third time to Hell, and it has survived every trip completely unscathed. Can't say that for the three KTM's we met half way across. Guy said he had never crashed his bike so much in one day. You can see the broken bike parts that have paid homage to Hell in the rock carne at the base of the 5MOH sign. I did go down once, in some of that stinking 7 inch deep sand in the bottom of one of the canyons, but it was a nice slow soft tip over, so I just lay there in the sand a caught five winks. Man my thighs are burning today though after riding 18 miles of that stuff, it's actually 9 miles across (we rode it both ways, which the KTM guys could not believe!) So anyway the bike runs great again! Gotta tell yoiu, I'm loving that Scorpa! If you ever want to see what you...and your bike...are made of, I highly recommend that you go to Hell and find out! All five..er nine...miles of it! Edited April 8, 2013 by ridgrunr Quote Link to comment Share on other sites More sharing options...
janwillem Posted May 3, 2013 Report Share Posted May 3, 2013 Thats a great looking bike. And the 5 miles of Hell looks great to! I wish we could do a stint like that in our realy small country. Thanks for the tip i think i will try it on my Scorpa to. I have to agree with you, i only have my 2006 Scorpa for 2 weeks no and i realy fell in love with it. Quote Link to comment Share on other sites More sharing options...
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