May 25, 200521 yr Anyone got any set up info for the sherco 4t yet mine is a lot smoother and more powerfull after the second service (did one at 5 and one at 10 hours, just to be sure) but it still needs no choke on initial start up and will flood if i try it. do i need to lean the mixture,or move the needle setting. or change the pilot jet. it runs ok when warm but seems quite thirsty
May 25, 200521 yr My 4T requires the choke to start and run when cold. Runs fine when warm although can be a sod to start when hot. Maybe too lean on the mixture or the wrong technique for starting when hot? Also mine drinks fuel at an alarming rate, not helped by the distance between 4th and 5th gear!
May 25, 200521 yr Dabster measured my 4T float level and is 18.5, so appears same as 2 stroke, 4T Stock carb' setting...on mine! Slide 45 Pilot 32 Main128 mixture screw 1.5 turns out How does this compare to the 290?
May 25, 200521 yr My 05 290 33 pilot 126 main Slide standard mixture screw near yours, optimax fuel so looks similar, so why no need for choke? Why would it flood? Up or down on the needle?
May 25, 200521 yr Excuse my comment but there cant be much to gain by comparing 2stroke and 4stroke carb settings. How is everyone who has bought one finding the 4T Sherco, there seems to be two distinct camps with th Honda - hate it or love it with very few people in the middle ground. As for reliability - any problems yet, given the problems that have been publisised at the SSDT.
May 26, 200521 yr As the carbs are identical they may well be the same set up from the factory, who would think that a 125 is the same as a 290, not ness the same comparison but they are. Only trying to help the bloke not prescribe carb settings based on a 2 stroke, in case you were not clear.
May 26, 200521 yr They aren't exactly the same. Both are Dell'Orto, but 2stroke bikes use the wellknown PHBL26BS and the new 3.2 4T uses the relatively new VHST28BS (flat slide, bigger bore, emulsion-type pilot jet). This VHST carb series seems to have some problems with the float level, caused by the needle-float set. These problems are erratical, so may be present in a bike an not in other. (You could read more on this in http://www.terra.es/personal9/marlintec/taller , in the VHST section, chapter VI, in Spanish) Furthermore, I know that some tests with Keihin carbs are being developed in the 3.2 4T nowadays. In relation to the SSDT problems, seems to be addressed to the ignition system. A bike also developed the problem in Spain (not much rain) so it seems not to be a problem of wet, but heat on the coils. I'm very confident that in Sherco will soon resolve these problems and we'll have a serious alternative to the 4RT. Cheers, JM.
May 26, 200521 yr Marlintec My 4T exhibits some strange carburation, seeming weak, then rich for no apparent reason. Following your link, the google translation is not perfect but it would appear you have identified a problem with manufacturing of the float needle and housing. Am i reading this right? You solved it by fitting a float needle/seat from a PHBL type? Was it a straight swap?
May 27, 200521 yr RE500 your reading is right. The rich-lean-rich-lean-lean-rich-rich-lean... with no apparent reason is the symptom of a fail in the fuel input to the carb. This could be a clogged line, a non-vented tank, a small floatneedle jet or as in this case, an erratical float level. You may check your float needle and ask to a friend to borrow his PHBL set. it's just a straight swap, yes. BUT... in your bike there is one more thing to check: the heating of carb. A very warm carb also gives the rich-lean-rich-lean-lean-rich-rich-lean... symptom. It may not be a problem in UK... or do it? In relation to this, I remember the same problem in the bike of Eddy Lejeune when he changed from the old 360 to the new RTL engine. After all these years, when Honda bets for fuel injection in a trials (it could be done before in any CRF or CRX)... it is also a 'symptom' to bear in mind. Cheers, JM. Edited May 27, 200521 yr by Marlintec
May 27, 200521 yr In hot conditions it would be easy to fit some of that heat sheild Sherco use on the underside of the rear fender! between the carb and head, like Honda did with the RTL, also could test a peice between the ign coil and head.
May 27, 200521 yr Marlintec Does the PHBL float needle have a spring on top ? Carb doesn't seem to get warm at all, even when the motor is well toasty. Thanks for the suggestions though! Haven't popped the tank off to check the temp of the coil, i'll stick a thermocouple to it and see.
May 27, 200521 yr Sorry, RE500, I don't exactly understand what you mean with ''spring on top''. The top (tip) of this needle is covered with rubber, and the body has a tiny spring within (you cannot see it) that pushes out the T shaped part. Seems that a change on the stamping machinery of Dell'Orto has produced some defective units that were mounted on VHST carbs. You can easily found this needle on any bikeshop, but make sure that is of the same lenght and size. Also, I'd like to know your temperature tests! Ishy, I think there are people that testing the insulation sheets between head and carb, as you note. I don't know if the problem with ignition is on the HT coil or in the mag coils. The bike I referred before was changed all the electrics, and I don't have more news on which was the faulty part.
May 27, 200521 yr Marlintec The needle valve has a bent thin gauge wire fixed to to the top that forms a loop. This hangs onto the float arm/lever. The float arm/lever doesnot have a notch for a T shapped needle valve to fit. Does this make any sense...if not i'll take a picture tonight. Cheers
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