| Author | Message | ||
     Hx214 |
Picked up this S1 last fall. Haven't had it very long and just started riding for the year here. Last fall I rode it a few times and it would get a slight hiccup/shudder at cruising speed. I thought maybe the cold air was messing with the carb so I didn't think much of it...it seemed like in the mornings when it was colder it would shudder more than in the afternoon when the air warmed up. Every once in a while when I shut her down I will get a backfire. Yesterday I took it out for about a 200 mile ride. It fires right up without issues and will warm up without issues. Grab the throttle and there is no hesitation and it takes off. It only seems to be at cruising speeds that I will get the hiccup. It's not really that big of a deal because it runs like a dream all the other times, but something just seems a tad off. It has aftermarket intake and VH exhaust. I did run a can of sea foam through it on the first tank (thinking about running it again) and I only use 93 octane. Plugs seem clean, but not super clean like it is running way to lean or something. Just wondering if this is normal or if I should try to adjust the carb. Any insight would be great! | ||
| Rick_a |
Mine did that stock. See what jets are in the carb. IIRC with a V&H and CV mine was running a 45 low and 195 main, with the needle shimmed a bit. | ||
| Bluzm2 |
Rick, that sounds about right. Depending on the motor, the 195 might be a notch too big. I've got one t-Storm motor that likes a 190 and one that likes a 195. Both have 45 pilots and a .050" shim under the stock needle. | ||
| Skntpig |
Check intake seals for leaks. | ||
| Lager |
What you are describing is a lean condition. It can feel like a surge, or a uneasy feel in the engine. Hiccups can occur, that usually is caused by a POP back thru your intake. Without going into a long post about carbs and how they work? Here is the skinny. Idle jets are used only during idle, they only effect mixture at idle. Main jet sizes are for wide open throttle situations. The rest of the time, the mixture is controlled by the needle. Its taper determines how much fuel is metered between idle and wide open throttle. Notice the slide needle is tapered.Skinny at the bottom, thick at the top. The more throttle imput, the skinny part allows more fuel to flow. To allow for fuel at the same air induction thats controlled by the slide, you either need to change the needle taper,or raise the needle somehow in its holder, which is the slide. Most folks shim the needle upwards due to cost. When you do so, what happens, is at the same same air flow, your allowing more fuel because the needle is riding higher,thus more fuel to pass by creating a higher fuel to air ratio then what the factory decided it needed to pass emission standards. Since you changed exhaust and intake air to flow more freely,you now need more fuel. The above,is all about on how you get it.. If you understand all of this, you have passed Carb 01 class in any of the Motorcycle schools out there. Hope this helps? | ||
| S1owner |
Mine does the same thing it has similar mods had it looked at and was told a diamond head Carb kit will fix it. Has to do with air intake and performance. | ||
| Hx214 |
Thanks Guys! Lager thanks for the description. I have messed with carbs in the past with a little bit of luck. I have rebuilt a few bikes for a few people and I had a little Ninja 250 that someone had installed pod filters on that I had to shim the needles for to keep from bogging... I'm not a pro at it, but I get what you are saying and I appreciate the help! Update on the bike though.... It has been in the high 70's low 80's the last few times I have ridden. The bike has run like a dream and hasn't givin me any issues like I had the day I described in the first post. I had one isolated issue when I went into a valley around dusk and I could feel the air temp get much cooler very quickly and the bike "hiccuped" again... but only once... we pulled out of the little dip and the air temp raised and it ran fine the rest of the trip. I have had trucks in the past do similar things when gaskets start to go. Anytime it would rain a bit, I had a truck with a bad head gasket that would shudder and stall out. I'm wondering if it may be an intake gasket issue like skntpig mentioned. I will get a backfire still about once every 5 starts.... The bike runs like a dream otherwise, and I think I am just going to keep riding it as is unless I start to get issues again...Close to 700 miles this week end on her and that isolated issue was all I had.... so I think I'll just let it go and enjoy the ride for now! Thanks guys, I'll keep you posted! |
