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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> Rough running at idle...I know...petcock, right? /cgi-bin/YaBB.pl?num=1448041567 Message started by stewmills on 11/20/15 at 09:46:07 |
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Title: Rough running at idle...I know...petcock, right? Post by stewmills on 11/20/15 at 09:46:07 2008 LS650. 5400 miles. All mods listed in footer/signature. OK...bike was running ok before but I felt like the stock petcock was causing a sputter now and then so I: a) got a stock petcock rebuild kit and installed it. b) cleaned the carb for good measure (it was super clean already) and installed Dave's stainless allen screws. c) new front brake pads. d) installed my rear pulley shim. Now I know "c" and "d" have nothing to do with this, but I am just splanin' it all anyhow. Yesterday was the first really good ride I did since the maintenance above and on the 8 mile trip to work it ran top notch. Stopped and fueled up half way and then drove the remaining few miles to work. On the way home after a few miles in, I felt like the response to my throttle adjustments around 45-55mph were jerky. The closer I got to home I noticed that if I didn't stay in the throttle pretty good at a stop light the engine would cut out. I babied it home and tried to adjust the air/mix with no impact. Switched the petcock to reserve/prime sveral times just to see if maybe the new petcock innards were stiff and needed a little jogging. Prime seemed to make it not choke out as bad, but still not running all that great, especially at idle. I drained about a cup of fuel from the float bowl drain and it seemed to flow pretty well and clear. Had a few specs of stuff in there but I think it was from me using a cup with some dust in it. Subsequent draining showed a clear, clean cup. I know I need to pull the fuel line off the carb and test the flow directly and as well do the old petcock test to see if in fact the stock petcock is still failing despite the new innards. I am also going to see if the local small engine shop has a vacuum line to replace the stock one for good measure also. Anyhow, aside from knowing what I need to look at as noted above, why would the bike run "ok" at speed but really piss out at idle? If it's not a petcock or fuel flow issue, could it be that some trash snuck past the petcock screen and has jammed up one of the jets? With my new allen bolts I can and will check and clean the jets again for good measure although they were spotless 20 miles ago when I cleaned the carb. I know...I know...get the raptor anyway! |
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Title: Re: Rough running at idle...I know...petcock, righ Post by verslagen1 on 11/20/15 at 10:02:24 well, obviously, you've put the brake pads in upside down. ;D jk. check the screws on the back of the petcock, but I don't think it's the issue. It maybe that you were leaning out before and just had your idle screw adjusted to compensate. and now things are sealed up a little better it's too rich. |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Serowbot on 11/20/15 at 10:12:40 76716072686C696976050 wrote:
Yaahuh... :-?... |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Todd James on 11/20/15 at 10:30:18 Bad Gas ? You fueled it up on the way to work. Maybe you got a heavy dose of ethanol or some water in the gas if the tanker recently dumped a load at the gas station. Other than that, or the petcock, it sounds like a vacuum leak. Perhaps you have a screw loose (on your carburetor). ;D |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Dave on 11/20/15 at 11:42:40 I would do the test where you block off the petcock vacuum line and switch to PRIME....and see if it makes any difference. If it does.....then the petcock might be working weird as you stated. |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Art Webb on 11/20/15 at 11:47:09 How to repair Savage petcock 1 Buy Rator petcock 2 remove stock petcock 3 install raptor petcock 4 stomp stock petcock flat (wear boots, preferably heavy engineer's boots) 5 throw stock petcock as far as you can away from your bike 6 shoot stock petcock, preferably with a slug out of a 12 gauge 7 burn what's left of stock petcock Sorry, just had to ;D |
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Title: Re: Rough running at idle...I know...petcock, righ Post by stewmills on 11/20/15 at 12:13:01 Dave: Yes, will do that test. Todd James: Yes, I thought about that too but the gas came out of the float pretty clean. However, I think I may drain it so I can check the petcock innards and go get some fresh gas. One of the pumps was bagged so I wonder if it was because the tank was getting low and that particular pump "died" first, hence pulling crap from the bottom? Versy: But they were Hello Kitty brake pads from Japan and I put them on with her standing right side up...those Japanese must have printer her picture on there upside down. Serow and Art Webb: http://thewellnessdoer.com/wp-content/uploads/2013/01/child-with-tongue-out.jpeg?2c8187 |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Dave on 11/20/15 at 12:18:20 For a lot of folks the stock vacuum petcock works just fine....and for a long while. The big problem with them is that when they act up - the symptoms are easy to mistake for some other cause like ignition or carb, and sometimes they can fill up the airbox or crankcase with gasoline. Sometimes folks spend a lot of time trying to correct the problem by looking in the wrong area. Failure can also be speeded up by the E10 and reformulated fuels that exist in some parts of the country. I suppose it isn't all that big of a deal....as long as you carry a small rubber plug and a golf tee - so you can disable the vacuum line and set the petcock to PRIME when you are out riding and the petcock decides to fail. That way you can get back home and do a proper repair when needed (install Yamaha Raptor).. |
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Title: Re: Rough running at idle...I know...petcock, righ Post by verslagen1 on 11/20/15 at 13:10:18 Stewie! you dog you... got a little pu$$y on your bike... awesome. ;D |
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Title: Re: Rough running at idle...I know...petcock, righ Post by norm92de on 11/20/15 at 13:21:45 Dave, My son has one of those. Sweet dog, his name is Tachi. :) |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Dave on 11/20/15 at 18:55:37 3534293662693F3E5B0 wrote:
In the photo......looks more like a dog that needs an attitude adjustment! |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Art Webb on 11/22/15 at 08:46:40 I thought my tech advise was spot on Dave said it well, when the stock petcock fails, as it will, the symptons can send you on wild goose chases non vac ptties don't do that :P |
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Title: Re: Rough running at idle...I know...petcock, righ Post by stewmills on 11/27/15 at 10:14:29 ok gang. to diagnose things one at a time i first replaced the vacuum line today. took it a minute to warm up and after a few minutes it seems to be running good now. i am probably over anxious since it was acting up befire, but when i rack the throttle open pretty good in neutral and let go it drops back a bit below idle speed then immediately catches up to a good steady idle. prob did this before and is to be expectd on a manual carb. before it would drop off and shut down, so I guess it was a leaky 7 year old vacuum line. we'll see what the next few rides do but hopefully that was it. |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Dave on 11/27/15 at 11:16:50 2F28392B313530302F5C0 wrote:
The engine will never be able to respond well to this kind of activity....and you shouldn't expect it to. When you open up the throttle and get the engine rpm up, and then instantly close the throttle you are creating a situation that makes the fuel mixture very lean. The fast spinning engine and closed throttle creates a very high vacuum - but the slide has dropped down and closed off the needle jet and main jet...so the only fuel that is getting to the engine is from the pilot jet circuit. The fuel mixture is so lean that the spark plug cannot ignite the mixture, and as the engine coasts down to lower rpm the engine technically is not running. Once the engine speed drops down low enough that the engine vacuum is normal, the fuel/air mixture finally gets back to normal and the spark plug can once again ignite the mixture in the cylinder and the engine starts to run again. Revving the engine up and closing the throttle quickly while the engine is in neutral is really not something that you should do.....the engine doesn't like it. Even when riding you should get in the habit of rolling the throttle on/off in a smooth manner.....cracking the throttle open or shut quickly just isn't a style that the Savage responds well to. |
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Title: Re: Rough running at idle...I know...petcock, righ Post by stewmills on 11/27/15 at 12:46:18 thanks dave. i do typically treat her well and am easy on the throttle action. i was just being nore aggressive than usual trying to see if i could get it to choke out like it was before. sounds like im back to normal...well, the bike anyway... ;D |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Sonny on 11/30/15 at 18:22:53 47545251434444260 wrote:
The important thing is not to mess around. I put my stock petcock in a ziplok bag, filled the bag with epoxy resin and let it harden, wrapped the bag in 3 layers of duct tape, tied it to a brick, then took it to the dam at our nearby lake and dropped the whole thing over the dam into the deepest part of the lake. At midnight. When no one was around. So far, no further problems with that petcock, and the Raptor is working great. :D |
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Title: Re: Rough running at idle...I know...petcock, righ Post by justin_o_guy2 on 12/01/15 at 22:22:44 Note to self Do Not Piss Sonny OFF! |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Sonny on 12/01/15 at 23:23:49 You know, I have thought a fair bit about that OEM vacuum petcock. It's way more complicated than a simple off/on/reserve valve, and why? One reason. So you don't have to remember to turn the gas on and off. In return, you get a system that impersonates every type of carburetor problem when it begins to fail, causing endless confusion about what is wrong with the bike and money and effort spent fiddling with things that aren't broken. It's almost like the designers thought, hey, let's put this infernal thing on there and it will look like we are doing the owner a favor when in fact we are generating a huge amount of parts and maintenance income for the dealers. Let's design it to go bad in 4 or 5 years and let's make the part expensive to boot! No, Art and me are nice guys, we're just teaching a new Savage owner how to think about that steenkin' stock petcock. 8-) |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Sonny on 12/01/15 at 23:34:57 Oh wait -- that was StewMills on the original post! He already knows this stuff good and well! Never MIND! :-[ |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Dave on 12/02/15 at 03:41:57 55494845494A260 wrote:
Just about every new motorcycle has an automatic petcock or a fuel pump, these days......another part of the system that makes your life convenient, and safe. The kick stand safety, clutch safety and automatic petcock are there so you don't have to think "too much", and protect you if you do happen to stop thinking for a moment. Those safety devices probably helps a lot of new riders - for most of us old folks we already have the routine down pretty well as we learned long before those safeties were on motorcycles. The downsides of all the safety devices is that they add some weight and complexity to the bike, and they can fail and be somewhat hard for folks to diagnose on the side of a road. The petcock and sidestand switch are the two most common failures that can really get you looking in the wrong place to solve the problem. I am not sure if the other bikes with vacuum petcocks have as much failure as the Savage does......my Ninja 250 and 250 Super Sherpa both had vacuum petcocks, and the 1972 GT550 Suzuki tank I put on my bike came with a vacuum petcock on it. And when it comes to safety interlocks....the ones on new mowers drives me crazy! My mother's Cub Cadet stops the mower blades whenever you back up, and the interlock on the seat is far too sensitive and when a bump causes you to get a little light on the seat...the interlock stops the cutting blades as it doesn't think you are still sitting down. It takes about 10 feet to get stopped when this happens, then you have to back up and restart the mower deck so you can cut the part that wasn't cut when the blades stopped. (If it was my mower I would have those interlocks (reverse and seat) bypassed before I ever used the darn thing). |
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Title: Re: Rough running at idle...I know...petcock, righ Post by justin_o_guy2 on 12/02/15 at 07:29:23 I recently acquired another mower. It's fast enough, and the driver isn't pushing a pedal to make it go, it's Going, and I rode it through some rough areas where the other mower gets stuck. Dang near threw me off, so, I hooked up the seat switch.. but the old one, you wanna back up, you either Kill the blades Or Push a button, turn the key to Reverse with blades Then put in reverse Or it shut off. Yeah , for about two times.. then, I wired around that crap. |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Sonny on 12/02/15 at 07:42:08 Yep, I have a 10 year old riding mower with all safety features defeated so the thing is usable. And I engage MC kickstand kill switches just often enough to know I am the idiot they put it on there for... |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Art Webb on 12/02/15 at 09:17:04 safety devices to help us not learn to operate a bike properly ;D |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Dave on 12/02/15 at 10:46:28 32212724363131530 wrote:
Well I have turned the clock back on my bike a little bit. Manual Petcock, no clutch safety, and no kickstand switch anymore. That'll teach em not to try and keep me safe against my will! |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Art Webb on 12/04/15 at 11:17:17 I got the manual petty. so far no probs with other devices, so they still exist ;D I'd really like to do more to it, but time and funds disallow |
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Title: Re: Rough running at idle...I know...petcock, righ Post by cheapnewb24 on 12/04/15 at 13:56:28 When I had trouble, it was from fuel starvation resulting from garbage in the screen behind the float valve. If you are having limited fuel delivery, then letting off on the fuel or shutting the engine off and turning it back on should help, but with the vac petcock, this effect is limited since reducing/eliminating the need for fuel will also reduce/eliminate its delivery. I have a manual petcock. The garbage resulted from a filter tube having fallen off. The idea is that the float bowl holds a small reserve of gas. If demand is higher than supply, the bowl will run low, resulting in starvation. After a little while, the bowl will refill. For me, it was enough to get out a few miles before having to pull to the side of the highway... over, and over, and over, and over. :P After a half-dozen, or maybe a dozen times pulling over, I'd manage to limp and crawl the bike to its destination :P. |
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Title: Re: Rough running at idle...I know...petcock, righ Post by cheapnewb24 on 12/04/15 at 14:06:02 2935343935365A0 wrote:
The important thing is not to mess around. I put my stock petcock in a ziplok bag, filled the bag with epoxy resin and let it harden, wrapped the bag in 3 layers of duct tape, tied it to a brick, then took it to the dam at our nearby lake and dropped the whole thing over the dam into the deepest part of the lake. At midnight. When no one was around. So far, no further problems with that petcock, and the Raptor is working great. :D [/quote] Uhhh... Why didn't you just take some torches and melt the thing already! Oh!... I guess that would just spoil all the fun, now wouldn't it ;D Gotta have all those different steps! ;D |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Sonny on 12/04/15 at 15:12:31 [/quote] Uhhh... Why didn't you just take some torches and melt the thing already![/quote] That would have worked fine. I musta been out of acetylene at the time, and my feelings toward the stock petcock were running so high I elected to give it the full Alfred Hitchcock treatment. Half measures will not do with a Savage vacuum petcock. It is pure evil. It will climb back out of a trash can onto the garage floor, you will step on it and destroy your foot. |
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Title: Re: Rough running at idle...I know...petcock, righ Post by cheapnewb24 on 12/04/15 at 15:47:28 ;D |
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Title: Re: Rough running at idle...I know...petcock, righ Post by Art Webb on 12/06/15 at 21:21:51 I is indeed evil beyond the grave and it must not be allowed to return or worse, SPAWN :o |
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