SuzukiSavage.com /cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> New to me S40 ,need to solve rough running issue /cgi-bin/YaBB.pl?num=1498776859 Message started by antmanbee on 06/29/17 at 15:54:19

Title: New to me S40 ,need to solve rough running issue Post by antmanbee on 06/29/17 at 15:54:19 Hi all, I have been reading on this forum for close to a year and finally got an s40, 2005 with 4K miles. Had many bikes since the late 70s, mostly Italian but have been intrigued by a big thumper. So far I am preparing by ordering stuff like a raptor petcock, oil filters, Batterytender Lithium battery. The bike starts, just barely runs and it is very rough and I can not give it gas, wont rev or make any power. It sat for not sure how long since last running, probably a year or so in a garage. Battery is weak even after charging but it cranks fine if I have jumper cables attached to another battery in one of my other bikes. This weekend I will probably have the raptor and replace the petcock and if that does not resolve the problem I will drop the float bowl and clean the carb a bit. I would appreciate any feedback as to other usual or possible causes. I will be changing the oil with rotella t4 this weekend too. Thanks, antmanbee

Title: Re: New to me S40 ,need to solve rough running iss Post by 1st2know on 06/29/17 at 19:01:07 Sounds like you have a good plan. Things to keep in mind: - if you have the battery out, you're only 4 10mm bolts away from removing the battery box, which makes it much easier to either remove or clean the carb. - Place a towel over the starter and transmission as to catch small parts as gravity sucks them out of the carb. I had one fastener that fell through a small hole on the left side and then on to the belt, and I had to remove the front pulley cover to rescue it. - Budget for replacing the carb fasteners(I think there are 8). The stock fasteners are JIS ("Phillips-like") screw heads, and they tend to get rounded easy. If have to go back in to the carb, you'll thank yourself for replacing them with hex-key fasteners.

Title: Re: New to me S40 ,need to solve rough running iss Post by stewmills on 06/30/17 at 07:07:11 Saying this from having done it a lot and knowing it's not that difficult, I would clean the carb regardless to eliminate that as being any part of the problem. No telling what could be in there if it sat from the previous owner. - You may need an impact driver to get the screws loose to open the carb. As noted, they are JIS screws but you can grind the tip of a phillips bit to make it fit these JIS screws a bit better and lessen the chance of stripping them out. As available, replaces with allen screws as 1st2know indicated. - Be careful with the plunger, Don't tear it or poke a hole in it, and when reinstalling in the clean carb make sure there is no grease or fingerprints on the carb body or slide. Little things can cause the slide to stick.  Personally I cleaned mine with WD40 and lightly dried with a lint free cloth. Make sure you put it back in correctly with the little nib in the diaphragm top in the associated nib in the top of the carb where it seats and seals. Once you have a clean carb, fresh new fuel, raptor, we can tell if it is then another issue such as jetting?  Best to do one thing at a time and isolate the issue than doing a laundry list of things at once, but a petcock change and carb cleaning are a must regardless. Lastly, in case you're thinking about it DON'T connect to a car battery with a car running as it can be too much juice for these bikes. Connecting to a non-running car is OK, just don't crank the car up.

Title: Re: New to me S40 ,need to solve rough running iss Post by Dave on 06/30/17 at 07:36:50 As the fuel in the float bowl goes bad/stale/evaporates during storage....the small hole in the pilot jet is the first thing to plug up, and in extreme cases the main can also become clogged/corroded/gunked up. Bringing any bike out of storage should include a complete carb cleaning, and inspection of the rubber parts.  The diaphragm in the TEV valve can become very stiff as it ages, the tip of the float needle can become stiff and cracked, etc.

Title: Re: New to me S40 ,need to solve rough running iss Post by antmanbee on 06/30/17 at 09:34:16 Does someone know off the top of their head what the size of the carb bolts are and how many so I can pick up a set on my way home? My cheap ass jumper cables wont pass enough current to start a car so it is doubtful they could damage anything. But I am using the battery in my unstarted Guzzi that is parked next to the s40 for the jumping. The bike was owned by a woman and it appears that she made no mods at all so it more than likely has stock jetting and the exhaust is stock. I hope the raptor mostly cures the problem as I don't want to get into the carb this weekend if I don't have to. I know I will be into the carb later as I plan to probably add a dyna and switch to a pod.

Title: Re: New to me S40 ,need to solve rough running iss Post by justin_o_guy2 on 06/30/17 at 10:27:09 An 05 with 4,000 miles. Unless someone got it running to sell, bet on the carb being crappy, especially if someone intended to Keep it Alive By starting it occasionally. Every time they started it they filled the bowl, only to let it evaporate and gunk up the innards.

Title: Re: New to me S40 ,need to solve rough running iss Post by stewmills on 06/30/17 at 11:46:19 Courtesy of Dave:

Title: Re: New to me S40 ,need to solve rough running iss Post by batman on 06/30/17 at 12:24:52 clean the junk from around the sparkplug before removal,clean and check the gap .031 to .035

Title: Re: New to me S40 ,need to solve rough running iss Post by antmanbee on 06/30/17 at 14:59:15 Thanks for the picture of the carb. Just what I needed. Are stainless recommended or steel of what spec for the bolts? I'll be sure to blow out the debris from the plug hole.

Title: Re: New to me S40 ,need to solve rough running iss Post by justin_o_guy2 on 06/30/17 at 15:02:56 Stainless Steel Allen head bolts. Use antisieze.

Title: Re: New to me S40 ,need to solve rough running iss Post by Dave on 07/01/17 at 05:57:55 http://suzukisavage.com/cgi-bin/YaBB.pl?num=1488995381

Title: Re: New to me S40 ,need to solve rough running iss Post by piedmontbuckeye on 07/01/17 at 07:55:32 I would suggest purchasing the stainless screws/bolts from McMaster-Carr.  You do have to buy quantities (5 per pack, etc. for example) but the overall cost will probably be less than "package deals."  I had replaced virtually all external screws/bolts on my BMW from them. I have dealt with M-Carr for literally for years and NEVER had an issue! They have a great catalog online and ship to anywhere.

Title: Re: New to me S40 ,need to solve rough running iss Post by antmanbee on 07/01/17 at 08:08:26 I have a fastenal store near by and have got some stainless for my Guzzi from them. I will look over the bike and maybe do some other stainless replacements too besides the carb.

Title: Re: New to me S40 ,need to solve rough running iss Post by antmanbee on 07/01/17 at 09:59:48 Pulled the carb off and dropped the bowl. Pretty gunked up.

Title: Re: New to me S40 ,need to solve rough running iss Post by justin_o_guy2 on 07/01/17 at 10:48:35 Well, There's yer Prawblum! Stolen from Mythbusters.

Title: Re: New to me S40 ,need to solve rough running iss Post by antmanbee on 07/01/17 at 11:31:30 I've rebuilt quite a few carbs but I don't recall one this dirty in the jets and float bowl. The butterfly valve and bore and exterior look like new. What a contrast.

Title: Re: New to me S40 ,need to solve rough running iss Post by antmanbee on 07/01/17 at 16:28:47 Well I got fresh oil and filter (rotella), Raptor petcock and a cleaned carb. It runs better but still not good. I rode it around the block ant it was hiccuping and backfiring quite a bit even all warmed up. I have the airbox out, so no filter, just the rubber air intake attached to the carb. The jets are stock size I am sure. I removed the idle mixture plug and the screw was all the way in. I backed it out a few turns till the bike idled higher and that helped a lot. I will be putting a uni filter on the rubber air intake so the engine intake breathing will be apparently more open than stock. I have a hard time believing that the stock is so restrictive that it would run so poorly with it removed. Tomorrow I will remove the carb again and shim the needle as prescribed by many here and see what that does.

Title: Re: New to me S40 ,need to solve rough running iss Post by justin_o_guy2 on 07/01/17 at 17:28:52 Removed the idle mixture plug and the screw was all the way in. That's new.. don't remember seeing that ever..

Title: Re: New to me S40 ,need to solve rough running iss Post by batman on 07/01/17 at 22:28:02 Without a filter the bike runs really bad,it is jetted lean  from the factory and removing the filter makes it much worse.a cone filter won't be much better you'll have to rejet the carb .

Title: Re: New to me S40 ,need to solve rough running iss Post by antmanbee on 07/02/17 at 05:06:45 I ordered one of the UNI filters. I don't think it will be much different than running without a filter jeting wise. I got this, https://www.amazon.com/gp/product/B000WJGTDG/ref=od_aui_detailpages00?ie=UTF8&psc=1 I will get a short piece of 2" schedule 40 PVC to attach it to the stock rubber intake tube. When I use a pod filter I always use the stock intake tube if possible to smooth the airflow into the carb or throttle body. Similar to a velocity stack.

Title: Re: New to me S40 ,need to solve rough running iss Post by antmanbee on 07/02/17 at 13:01:55 Well I got it running better today. Pulled the carb and took out the white spacer from the top of the needle and ground it down about half. Put it all back together and I could barely get it to run at all. Pulled the carb again and checked the float bowl and it was still clean, but I noticed when I blew it all out with air there was liquid that would keep coming from one of the brass floats near to where it was soldered onto the bracket. So I cleaned, sanded, wire brushed the float where the leak was and tried to get all the gas out of it and then attempted to solder where it was leaking. After soldering I dipped it in a bowl of water and saw no air bubbles, so maybe fixed, time will tell. Adjusted the float level to just slightly over an inch and popped it all back together and onto the bike. Checked the fuel/float level with a clear hose attached to the bottom of the bowl and unscrewed the drain screw. Fuel level looks like it is right at the gasket level. When I re-jet I will probably lower the fuel level a bit more. So it runs decently now but not great, but I will hold off re-jetting till I get it registered and my filter comes in and maybe until I can find a harley muffler. I got other stuff to do on it like replace the 12 year old tires that look great, no cracking or anything as the bike was stored inside. It also has the infamous bit of seeping of oil on the left of the engine where the head joins the block. I will probably get the aluminum plug for the fix but I will see how bad it is first.

Title: Re: New to me S40 ,need to solve rough running iss Post by ohiomoto on 07/03/17 at 05:48:17 I would throw the aribox back on and get it running right before I'd start jetting with that UNI.  If it runs right with the stock airbox, then you know the carb is good.  This will keep you from chasing your tail with the UNI.

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