curt531 Posted October 27, 2011 Report Share Posted October 27, 2011 Has anybody changed the jetting from std,can't seem to get mine to run clean, done all the checks,air filter,crank seals etc, but it still runs very rich, I am running a semi synthetic oil at 70:1 at the moment,was running a full syn oil, tried that at 80:1 & 100:1 but still really rich, that's when I changed to a semi, what are you guys using ? Quote Link to comment Share on other sites More sharing options...
copemech Posted October 28, 2011 Report Share Posted October 28, 2011 Has anybody changed the jetting from std,can't seem to get mine to run clean, done all the checks,air filter,crank seals etc, but it still runs very rich, I am running a semi synthetic oil at 70:1 at the moment,was running a full syn oil, tried that at 80:1 & 100:1 but still really rich, that's when I changed to a semi, what are you guys using ? Which carb is onit? Quote Link to comment Share on other sites More sharing options...
curt531 Posted October 28, 2011 Author Report Share Posted October 28, 2011 The bike is a std 2011 290,only thing I have done is fit a 1mm head spacer.The carb is a Dellorto. Quote Link to comment Share on other sites More sharing options...
copemech Posted October 29, 2011 Report Share Posted October 29, 2011 The bike is a std 2011 290,only thing I have done is fit a 1mm head spacer.The carb is a Dellorto. As I recall that bike (290)still came with the Dellorto VHST 28, as compared to the PHBL(round slide)on the 250. I have not owned one of these carbs, yet it is said that they are very sensitive to float level settings to within 0.5mm +- from the factory setting. I think it takes some real patience to make this carb work really well, and I would highly reccomend you give Chris Pearson at Splatshop UK a ring to discuss your best options here. Depending upon your requirements, you may be better off with a standard PHBL that tends to be less jikky in it's running, or there are other options. Quote Link to comment Share on other sites More sharing options...
curt531 Posted October 29, 2011 Author Report Share Posted October 29, 2011 As I recall that bike (290)still came with the Dellorto VHST 28, as compared to the PHBL(round slide)on the 250. I have not owned one of these carbs, yet it is said that they are very sensitive to float level settings to within 0.5mm +- from the factory setting. I think it takes some real patience to make this carb work really well, and I would highly reccomend you give Chris Pearson at Splatshop UK a ring to discuss your best options here. Depending upon your requirements, you may be better off with a standard PHBL that tends to be less jikky in it's running, or there are other options. Thanks for that, i was thinking of swapping it for a keihin that the 2012 come with as std, but don't want to go to those lengths if I can get this one to work Quote Link to comment Share on other sites More sharing options...
copemech Posted October 30, 2011 Report Share Posted October 30, 2011 Thanks for that, i was thinking of swapping it for a keihin that the 2012 come with as std, but don't want to go to those lengths if I can get this one to work As you have added the 1mm head spacer, you are obviously not concerned with ultimate performance of the bike, I would suspect you an average rider more wanting a good bike, yet a bit more mellow. This is where picking up a good std PHBL26 may be just fine for your use, or even an OKO (kiehin copy)26 which has proven sweet for some. Do tell yur thoughts on the 1mm spacer, as itseems there is little feedback on this. Seems most, historically, have reduced the timing a tad to settle things, all to taste! Quote Link to comment Share on other sites More sharing options...
curt531 Posted October 30, 2011 Author Report Share Posted October 30, 2011 Stripped the carb to check jetting, seems the last owner has made some changes going by the std setup in the manual. Std jet in the book are , main #128 pilot #33 needle clip 2ond + 1 clip 0.5 ( this is the exact wording in the manuel, not clear to me . ) float hight 21mm. ( not sure of the exact point you measure ) My findings are, main #126, pilot #36 needle 3rd clip ( middle with the small spacer washer on top ) float hight 19mm ( if measuring from the "o" ring face on the carb body to the tip of the levers with the carb up side down is the right place to measure ? ) The last owner did tell me he had an S3 head on it but took it off to sell it, he also said he had not changed anything ! On the subject of head spacers the one I fitted works really well,it just takes the sharpness away when you open the gas, it has no adverse affects on the mid & top end power that I can tell, rode a trial on it last week end & it was definatly easier to ride on the real slow stuff,just dulling the power in a suttle way. It's not night & day different but anything that makes riding the bike easier is good in my opinion. Quote Link to comment Share on other sites More sharing options...
splatshop Posted November 1, 2011 Report Share Posted November 1, 2011 Hi Please have a read through this, I think it will help. https://www.splatshop.co.uk/2010-2011-sherco-preparation Usually they tend to run lean though so you may find that it is your head spacer causing the bike to run rich and you may have to lean the mixture off, your pilot jet is a bit bigger than standard as they originally came with a S33, check to see if yours has a S or a U type Jet as if it is a U36 that sounds about right, see here for more details: http://www.splatshop.co.uk/dellorto-vhst-pilot-jets.html Quote Link to comment Share on other sites More sharing options...
nigel dabster Posted November 2, 2011 Report Share Posted November 2, 2011 A kehien worked much better than a dellorto on my 2011. Quote Link to comment Share on other sites More sharing options...
curt531 Posted November 2, 2011 Author Report Share Posted November 2, 2011 Hi Please have a read through this, I think it will help. https://www.splatshop.co.uk/2010-2011-sherco-preparation Usually they tend to run lean though so you may find that it is your head spacer causing the bike to run rich and you may have to lean the mixture off, your pilot jet is a bit bigger than standard as they originally came with a S33, check to see if yours has a S or a U type Jet as if it is a U36 that sounds about right, see here for more details: http://www.splatshop.co.uk/dellorto-vhst-pilot-jets.html Thanks very much for the help today, hopefully this will sort out the problem. cheers Paul Quote Link to comment Share on other sites More sharing options...
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