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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> 2007 Suzuki S40 - Low RPM engine bogging. /cgi-bin/YaBB.pl?num=1529605596 Message started by Crashmk1 on 06/21/18 at 11:26:36 |
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Title: 2007 Suzuki S40 - Low RPM engine bogging. Post by Crashmk1 on 06/21/18 at 11:26:36 So, as stated in the title , I recently purchased a 2007 Suzuki S40 as my second motorcycle. A short background - I've only been riding for about 3 weeks, and I had purchased a 1988 Yamaha Radian 600. It was a great bike, but it had a lot of oil leakage, and electrical issues. So, I sold it, and found a great deal on the S40 that I purchased this yesterday. According to the previous owner, at some point, the owner before them had tried to do some sort of exhaust pipe modification, and had messed with the carb in the process. I'm not very mechanically savvy, so I reckon this is my time to learn with a small, and relatively simplistic engine. While riding the bike (specifically 1st and 2nd), at low RPM, the engine will tend to bog down, though it gets a little better after the bike has had lots of time to warm up. So, all this being said, my main question is am I in the right thinking that this more than likely has to do with something in the carb/exhaust area? Or is there something else I should be looking into first? |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Serowbot on 06/21/18 at 12:12:08 How low is the RPM?... it shouldn't be below 1,000rpm or the top end will starve for oil. Has the muffler been opened up completely?... How loud is it?... An open pipe will run like krapola... |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Crashmk1 on 06/21/18 at 13:36:27 I'm talking like, low cruising RPM. Probably in the 2-3k range, if I had to guess. As far as the muffler goes, it sounds relatively stock. I'm not entirely sure what all was done to it during the said "modification". |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by verslagen1 on 06/21/18 at 13:57:09 2-3k rpm seems to be normal easy going accel. 1st off, check the petcock there's a thread for that in the tech section. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by batman on 06/21/18 at 14:01:50 Like all new owners ,you should look into the carb,what size jets do you have,is it clean,has it had the spacer mod, is the float level set right ,what is your location (elevation above sea level ) are there any holes drilled in the rear of the stock muffler? these are questions only you can answer,but info we need to have to advise you. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Crashmk1 on 06/21/18 at 17:06:07 To reiterate, I'm not super mechanically savvy. The original question was essentially just, does it seem like it would be a carb issue, knowing that the carb and exhausts have been messed with before. Most of this is information that I don't really know how to check. I'd probably be best off just taking it to a shop for now, until I know what I'm looking for. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by stewmills on 06/21/18 at 18:20:05 Don't waste your money on a shop. These are EASY things to investigate. If you can make an effort to answer the questions, we can save you a lot of money and probably have the bike running better than the shop because the people here are experts at these bikes, shops aren't. It is likely a carb issue or carb and exhaust. If you don't think you will ever have the will to let us walk you through opening up the carb, the answers to your questions are not able to be provided because that's where all the answers are. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Dave on 06/21/18 at 19:04:08 Where do you live? Maybe a local member can ride your bike and see if it runs like it should....or needs help. And maybe your local member would be willing to help. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Crashmk1 on 06/21/18 at 19:25:53 I'm definitely willing to learn. I just don't want to do more harm than good, as this is currently my only means of travel. I sold my SUV this week, because I'm going to be moving to Florida from Ohio in about 3 weeks. I'll be driving the Uhaul, in which I'm going to load the bike, and my fiance will be driving her smaller SUV, and we don't have an extra person to drive the other vehicle for us. So the bike will be my only means of getting around for a bit. The other main issue is, with the move, I don't have a ton of extra cash to dump into parts and whatnot, and my tool selection is functional, but probably not super adequate either. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by batman on 06/21/18 at 19:31:59 Labor is $80 an hour here in N.Y. at a dealer ,and they don't often work on them ,being "starter"bikes they are often sold to second owners and never see a shop . When you take it in they lay it off to there greenest employee ,and this is the person that doesn't know the bike any better than you ,who be doing the wrenching (and he might not care). Use this site and buy a Clymer manual ,and you'll learn how to fix/tune the bike,(better than the shop) and save tons of money.It may be that you need to adjust the fuel mix screw.(read through the Tech Section). |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by stewmills on 06/21/18 at 21:16:38 Can you stop in Auburn AL on your way to FL? A few hours here in my shop and we can tackle this and teach you. Serious offer. My home shop for free...not a shop with fees :) |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by justin_o_guy2 on 06/21/18 at 22:46:28 be driving the Uhaul, in which I'm going to load the bike, and Plenty of YouTube videos showing people fall off of ramps. Either be certain or have help. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Crashmk1 on 06/21/18 at 22:54:22 I certainly appreciate that offer! Unfortunately, the bike will have to be the first thing loaded, and the rest of our current 3 Bedroom house will have to be loaded around it. I have, however, already ordered the Clymer manual, so I will do some reading, and more research online. As for loading the bike, I will have a few friends available to help. Thankfully, these are light machines, so it shouldn't give me too much trouble. Worst case scenario, I have to ride the bike in, and filming will be forbidden, haha. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Crashmk1 on 06/21/18 at 23:58:36 Okay. So, through all of the research I've done this evening, I'm thinking that the cause of the issues may just simply boil down to air/fuel mixture being too rich. Symptoms: -bluing of the chrome header pipes -bogging down of lower rpms -occasional backfiring when applying clutch, or letting off of the gas I'm not saying that it is for sure, but could this be just as simple as adjusting the fuel screw to run slightly more lean? I figure it could be worth a shot, before tearing things apart anyway. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Dave on 06/22/18 at 03:54:17 0E3F2C3E2520267C4D0 wrote:
OK.....so you are currently in Oho. Can you perhaps mention a City? (Or are you on the run or in a witness protection program?) |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by batman on 06/22/18 at 06:02:29 Generally bluing of the pipe on these bikes are caused by running to lean,not to rich. the bike runs lean from the factory,to pass emissions tests ,that's why we tune the fuel screw and replace the needle spacer with 2-3(depends on elevation) #4 steel washers to raise the needle . this allows the bike to run more smooth/powerful( and remarkable difference ) and tends to decrease/stop most backfires. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Crashmk1 on 06/22/18 at 07:45:28 Ah, yeah, my bad. I'm currently living in Findlay, Ohio. Just south of Toledo. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Crashmk1 on 06/22/18 at 07:55:41 Okay, I read somewhere that the pipes could blue from either running too rich, or too lean. Can't trust everything you read on the internet. The pipes could have gone blue at any point. They were already blued when I got the bike, but I figured it might be worth mentioning. So could the symptoms also just be the cause of running too lean? |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by stewmills on 06/22/18 at 08:37:56 6F5E4D5F4441471D2C0 wrote:
Most likely blueing or bronzing of the header pipe is because of being too lean. The additional fuel, as contradictory as is may seem, helps for a cooler combustion. So, being lean from the factory means a hotter combustion hence the blueing or scorching of the header. More fuel (which the EPA tries to restrict by plugging the air/mix screw and making the carb lean from the factory) means cooler combustion and less chance of blueing. What we/you don't know as you stated, is how long it has been like this and did or did/not the previous owner make any carb adjustments or change jets. The only way to know is getting in the carb, looking at the jet sizes and needle setting, and then go from there. Heck, you may find that it just needs a good carb cleaning and that alone may provide some resolve. It could be simply a sticky slide. But if the carb is all stock you will likely reap some rewards by doing the needle spacer (white spacer) mod which richens up the throttle area where you are getting the bogging. HOWEVER, you could find that the previous owner raised the needle too much or put in an oversized jet causing an overly rich mixture. One give-away of an overly rich mixture is (at regular running temperature) is if you are getting any sootiness out of the muffler when you get into the throttle. You can also look back at the rear brake lever area behind the muffler and see if there is excessive soot back there. If not, you're probably just dealing with the classic factory lean issue. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Crashmk1 on 06/22/18 at 09:03:51 I double checked the rear brake area, and it seems perfectly clean. No additional soot there. So, it may just be running lean? If so, what does that mean? Just a screw adjustment, or will I still need to tear into the carb? I do plan on giving it a good cleaning at some point, but as stated before, this is my only means of transportation for at least the next 3-4 weeks, and I don't want to open it up myself and mess something up. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by stewmills on 06/22/18 at 10:01:55 Yeah, most likely a lean issue them. Well, you can try to do the air/mix screw adjustment on the right side of the carb with it on the bike but that probably isn't going to do you any good because the air/mix screw only impacts the mixture at idle. Once you get into the throttle about 1/8 turn or more you're operating in the area that the needle controls, and that seems to be where your issue is. If you don't want to risk it, maybe try running some sea foam through the next tank of gas. Also, as silly as it sounds, make sure you have good fresh fuel. If the previous owner let it sit and you are still running on his tank of gas, the ethanol in today's gas goes stale and you will get poor running of it's been sitting in the tank for several months. At the end of it all, you really need to get into the carb at some point and know for certain what you have going on in there. Truthfully, once you do it the first time and get the fear out of the way, you can drop, clean, and replace a carb in an hour or less. The only thing in there to be careful with is the 'rubber' diaphragm. As long as you don't tear it (it is quite durable) then the rest is just cast metal and brass jets aside from the plastic float. I never did it before I got my S40, and now I can do it blindfolded if I had to, thanks to the folks here :) |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Crashmk1 on 06/22/18 at 11:00:37 Added a photo to show the bluing. Gotcha. They very well could have let it sit for awhile. I mean, I was a little worried when I bought the bike to begin with. As of right now it only has about 4,200 miles, as an '07. So I expected the worst when I went to go see it, and ride it. Aside from the low rpm sputters, the bike runs and rides great. It belonged to an older couple, and the wife used it to commute to work. Their reason for selling was that apparently, someone had pulled out and cut her off, so she was scared of it at that point. I didn't think to ask how long ago that was. The bike was freshly washed when I went to go see it, so I'm guessing it may have had some dust from setting. Very well could be bad gas, I suppose. Would that cause any of the issues that I'm experiencing? The fuel doesn't particularly smell stale, but it could be hard to tell. I'm trying to reach out the previous owners currently to see what information they can give me. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by stewmills on 06/22/18 at 15:19:53 Nice bike. Identical to mine. Looks well taken care of. Stale gas can cause it to run not so perfect, but if they never got in the carb then it just needs the needle spacer mod. That bike is way too nice and clean to not be able to be fine tuned very easily. Can you tell if they removed the brass plug covering the air mix screw on the right side of the carb. If no, likely they were never in the carb as that’s usually the first thing that is done. If you aren’t sure, see tech section images, or take a closeup pic of the right side of the carb and post here. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Crashmk1 on 06/22/18 at 15:29:58 Yeah, the brass plug was removed, and left off. They gave it to me when I bought the bike. I toyed with it a little today, but I didn't really get any results from the air mix screw. We've had some heavy storms here today, so I haven't been able to mess with it all that much. First thing I'm going to try to do, once it dries up a bit, is get the mix screw back to factory settings, and go from there. Although, I think you were on the right track. After riding it, and getting a better feel for what RPM range it was sputtering in, it seems like it's going to be more in the main jet. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by NucleaRR on 06/22/18 at 15:59:09 Just noticing from the picture this bike has a Dyna muffler on it. This is a common mod on this site. Having the Dyna on there leads me to think the previous owner probably messed with the carb or did the white spacer mod. I, like others have stated, think checking the carb is in order. Basically to verify the jet sizes. You will also need to change these once you get to Florida because the elevation will affect your jet size and air/mix. See Lancers thread in the Market Place for jet kits. One question I have is, do you know if the petcock is stock? Mine, a 2005 had similar bog issues and would cut out at low speeds because of the failed gasket in the petcock. One other simple thing is idle RPMs, the PO of my bike had the idle screw turned too low which also contributed to the cut outs. Though at speed this shouldn’t be a problem for you. I only mention it because it will affect tuning the air mix screw and proper jetting. Definitely try to fix this yourself. You’ll have a better understanding of the bike and will be able to fix and diagnose issues if she ever leaves you stranded on the side of the road. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Crashmk1 on 06/22/18 at 17:47:03 The carb was definitely messed with at some point. I just haven't opened it to find out what all has been done. It appears that the petcock is stock on mine. I'll probably do the raptor mod, once I get a chance to. As for the sea level, where I'm currently located is around 800', in Florida, we will be in the 100' range. And so that means if I change the jets, I'll just have the change them again? Or is it just a tuning thing? |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by stewmills on 06/23/18 at 00:54:36 Hard to say what to do regarding jetting until you know what's in there. If you are lean at 800', you will be even leaner at 100'. Lower elevation equals denser air which equals more parts air per volume. So, there is even more air at 100' mixing with your same fuel volume. Until you know what's going on in that carb, everything is just an educated guess. This whole thing could not even be jet related if you found out that you have bad gas, a sticky petcock diaphragm, sticking carb slide, etc. First order of business should the easiest, fresh gas. Then try to run on prime to see if it is a sticky petcock. If prime makes it better, it is a petcock or a leak in the petcock vacuum line. After that, you just gotta get in the carb. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Crashmk1 on 06/23/18 at 06:38:06 I contacted the previous owners to confirm that it hadn't been setting. Last time it was ridden was about a month ago, and it had a fresh tank of gas the day that I picked it up. Can also confirm that running it on prime doesn't affect anything. Still wants to jump and stutter while accelerating. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by stewmills on 06/23/18 at 08:23:04 Cool, then it needs the needle raised first, test that, then consider jets. For reference, I am at ~600ft and have rejetted to 152 and 52.5 with the needle raised a couple of washers worth, and I’m running very smooth. Every bike can have its own minute quirks, but I bet if you were close to these settings in FL you will get the bik esmoothed out. Too bad you can’t stop by... :-/ |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by batman on 06/23/18 at 08:58:12 You have a need to read ! Before you do anything to the carb ,be aware that all the screws are not philliphead, they are JIS (Japanese industrial standard) . Philliphead screwdrivers are to pointed to fit all the way down into the slots in the screws and can strip the slots in the heads of the screws.( the worst being the soft and tiny brass screws ,you need to remove when doing the spacer mod) philliphead can be used if the tips are filed /ground to a blunter angle to allow full insertion into the slots . You should go to the Technical Section -and read about carb jetting, and the spacer mod, and how to tune your fuel screw. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by Crashmk1 on 06/23/18 at 13:15:27 Thanks Batman! I read the thread about it. I'm just wondering if it's something that I should wait to do (it's about 3 weeks until the move). I don't want to have to re-jet again once I get there. |
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Title: Re: 2007 Suzuki S40 - Low RPM engine bogging. Post by batman on 06/23/18 at 19:57:05 Well you could save some time and money ,if you can live with the bike the way it's running,for next few weeks. The stock jets 52,5 pilot 147 main are lean for anyone but those living at about 4000 ft (the Rockies) for your elevations @ 800ft - OHIO- I would say 52.5p-150 m -3 washers for the spacer, FLA @ 100ft-55 p- 152.5/155m - 2washers for the spacer, and retune the fuel screw after any /all changes.Your pipe isn't turning very blue ,the PO may well have put in larger jets when he changed to the Dyna muffler, this would provide a good idle and fairly strong running at 3/4 to wide open throttle ,but he might not been aware of the need to do the spacer mod ,which adds fuel at the speeds your feeling the sag (part throttle ( 1/4 to 3/4) /normal driving speeds- were your throttle spends most of it's time). |
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