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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> Idle mixture question /cgi-bin/YaBB.pl?num=1596139977 Message started by Keifer on 07/30/20 at 13:12:57 |
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Title: Idle mixture question Post by Keifer on 07/30/20 at 13:12:57 I've been using the starting point of 1.5 turns out as a beginning. I believe I've found the middle of the two 'highs' but I have a question. As the bike warms and the engine gets hot, the idle creeps up. When cold, I have to turn the idle up (so it's not loping) and later during the ride I find I need to turn it down as it's idling too high. Is this a symptom of too lean or rich? Also between shifts, when rolling off the throttle, the revs are very slow to drop. Is this related? Or could that be something else? No backfires, runs well otherwise. |
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Title: Re: Idle mixture question Post by verslagen1 on 07/30/20 at 13:18:55 725C505F5C4B0F0C09390 wrote:
Only time I have that is when the choke is still out. |
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Title: Re: Idle mixture question Post by Ruttly on 07/30/20 at 14:35:13 Idle mixture is best set with a hot engine Idle is best set with a hot engine , kinda high is best 1400-1500 rpm If its loping oil pressure is too low , bad for cam Anything else is jetting or bad petcock or plugged filter(s) |
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Title: Re: Idle mixture question Post by Gary_in_NJ on 07/30/20 at 16:30:06 You don’t set the mixture and idle for the traditional warm-up period that only last a few minutes, you set it after you have ridden the bike for 10-15 minutes. |
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Title: Re: Idle mixture question Post by Keifer on 08/03/20 at 10:21:16 Ok thanks for the replies... I still can't get the revs to drop reasonably after throttle roll-off. They fall very slowly between shifts, I have to just let the clutch out to slow the engine. And I can't get the idle to stop creeping up. It happens whenever I stop at a light after having ridden for a while. Throttle cable is not sticking, the carb has been taken apart and cleaned, no sticking butterfly plate, 155 main, 47.5 pilot, I'm basically at sea level (500-1000ft). Any other ideas? Perhaps I will look at getting a mini tach to help me out here. |
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Title: Re: Idle mixture question Post by Tocsik on 08/03/20 at 11:33:20 Maybe the slide is sticking or a the diaphragm has a hole or isn't seated right. |
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Title: Re: Idle mixture question Post by stewmills on 08/03/20 at 11:46:29 I'm not going to try to give a full diagnosis here as many factors can be at play, but one thing I learned to better understand while working on my Ninja 250 is what is called a 'lean surge'. It seems contradictory that less fuel would cause a surge, but read up a little on it. My point being that a 'surge' or simply a delay of the bike to go from 'speed' to 'idle' quickly and smoothly can sometimes be caused by a lean condition in one of the circuits or the idle mix. I tinkered with this on my Ninja and sure enough as I backed out the idle air/mix and kept blipping the throttle, I eventually turned it out and and enriched the mixture to the sweet spot where it didn't hang and the response was near perfect. But...as you have, make sure that everything on/in your carb is clean, not clogged, and not sticking before you start chasing the carburetor gremlins. This is the guide per the Ninja forum, just as a reference. SOme of our senior members may say this is or is not similar on the Savage so take it with a grain of salt... If the throttle hangs - The idle circuit is still too lean. Loosen the screw down a little more If the throttle drops below idle and takes a moment to return - The idle circuit is too rich. Tighten the screw a little bit. |
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Title: Re: Idle mixture question Post by verslagen1 on 08/03/20 at 11:51:25 787F6E7C66626767780B0 wrote:
carb gremlins... where have I heard that before?... oh don't tell me you still have the stock petcock? |
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Title: Re: Idle mixture question Post by stewmills on 08/03/20 at 13:28:54 746770716E6365676C33020 wrote:
Are you insinuating that there is ANOTHER petcock option besides stock? Never heard of such blasphemy! "Stock Petcock's Matter" |
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Title: Re: Idle mixture question Post by Keifer on 08/03/20 at 16:06:14 Thanks again guys, I will keep at it. Yes I have the raptor petcock ;) I did notice the slide had some of the graphite worn off, but not much. I didn’t want to lube it as I’ve read on here that causes sticking. So I just cleaned it. |
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Title: Re: Idle mixture question Post by eau de sauvage on 08/03/20 at 18:07:03 I have to just let the clutch out to slow the engine. You should be doing that anyway, it's called engine braking, FFIW I rarely use the brakes unless I have to, mostly I use engine braking. I keep an eye out if there are any cars behind me because they won't see any brake lights. I'll often cruise to a stop light and come to almost a complete standstill without using the brakes. |
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Title: Re: Idle mixture question Post by norm92de on 08/03/20 at 19:10:46 You can just caress the brake lever to turn on the light but not use the brake. |
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Title: Re: Idle mixture question Post by ohiomoto on 08/03/20 at 21:13:17 When cold, you should need to run the choke in the halfway position for a few miles to warm it up. Don't mess with your idle to do this and don't let the bike sit there and warm up. Ride it. That is the best way to warm up an engine. A 155 main jet is a little rich for most conditions (IMO) but shouldn't cause any major issues. 6C575B4B5153380 wrote:
This. Start with this. If you or anyone else took the needle out to do the white spacer mod and didn't put the retainer plate in correctly it could be part of the problem. There are two small holes in the plate that need to line up with the holes in the slide. If they don't your throttle will respond very sluggish. Also make sure the return spring and diaphragm are properly seated when you put it back together. You mentioned that you have some "graphite" rubbing off. If your slide is worn, you should consider replacing it. Mine was sticking and I messed around with jetting for a few weeks like a dumbass. When it got a little worse, I couldn't go more than 20 mph so I replaced the slide. It was the best $125 I spent on the bike since I've owned it. If all of that checks out, then start looking at the possible lean surge. |
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Title: Re: Idle mixture question Post by Keifer on 08/04/20 at 05:10:24 4D5F4B485F595B3E0 wrote:
——————— Engine braking imo refers to clutch already out and decelerating in gear. I was referring to between shifts only, it’s akin to ‘rev hang’ that most modern cars with manuals suffer from. For example, on 1>2 shift, the revs will barely come down without clutching out. I have a sneaking suspicion it must be the slide... I was just hoping to avoid replacing it as that’s an expensive part :( |
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