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SuzukiSavage.com
/cgi-bin/YaBB.pl General Category >> Rubber Side Down! >> Loss of power climbing hill /cgi-bin/YaBB.pl?num=1566144837 Message started by TTom on 08/18/19 at 09:13:57 |
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Title: Loss of power climbing hill Post by TTom on 08/18/19 at 09:13:57 Hey everyone, Was on a joyride last night and the bike was running great at a steady 50 mph for 15 minutes or so. I eventually started climbed a fairly good grade up a mountainside still at 50 mph in 5th gear and everything was pulling great when all of a sudden I had a drop off in power. As soon as I backed off the throttle to downshift I had some backfiring then engine quit. While still rolling uphill I was able to immediately get it to fire back up and turn around and head back downhill. I climb this hill regularly and have never encountered a problem like this ever. Bike didn’t do it again the whole ride back and rode like nothing ever happened.. Ant thoughts? I was thinking maybe some junk in my gas? Bike was just checked out at shop month ago during inspection. It’s a daily commuter for me so I’ll see if it acts up this week. 2013 w\ about 7800 miles. All stock. |
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Title: Re: Loss of power climbing hill Post by justin_o_guy2 on 08/18/19 at 10:56:09 A one time thing.. Until it's not. You said It fired right back up So Obviously it died. How did it die? Like someone flipped a switch? Chugging and struggling? |
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Title: Re: Loss of power climbing hill Post by TTom on 08/18/19 at 11:53:06 I did mention the engine quit on me in my previous post. I pulled in the clutch, heard some small backfires and as my clutch was pulled in the engine quit. I downshifted, started the engine back up and rode back no problem. |
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Title: Re: Loss of power climbing hill Post by batman on 08/18/19 at 16:22:11 50 mph is barely fast enough to be in 5th gear , and your trying to go up a steep hill? your dogging the motor, try 4th gear . Either that or your float level isn't set right.-( your float is hinged at the rear of the bowl ,going uphill the fuel shifts to the rear and tends to open the float valve sending more fuel into the bowl , which is ok if your in 4th gear at the same speed because the throttle has to be farther open ,which means your using more fuel ,if your in 5th at 50 your not, you might be flooding the bowl and the carb causing the bike to stall . Going downhill in 5th the opposite is true ,less fuel is entering the bowl but your using less ,so the bike doesn't stall.) Try the same hill in 5th gear but start up the hill at 60-65 and keep increasing throttle to maintain that speed to the top , and you'll most likely do just fine ,and it's better for the motor as well.If the speed limit is 50 use 4th ,if you drop to 45 use 3rd. It's not an auto tranny ,it's a MANnual tranny . be the man! :) |
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Title: Re: Loss of power climbing hill Post by ohiomoto on 08/19/19 at 06:32:22 Sounds like you lost fuel. First, get a raptor petcock. Stock petcock sucks. The other possibility is that you lost vacuum and the slide dropped, which would take the bike straight down to a lean idle. Lean because the butterfly valve is still wide open. This happened to me once, but the bike didn't stall. Not sure why it dropped, but my slide was worn and sticky. I replaced it and all is well. I "idle" uphills doing 50 every day on my way home from work BTW. Properly jetted, this bike is a tractor at any RPM. |
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Title: Re: Loss of power climbing hill Post by LANCER on 08/19/19 at 08:21:47 If you have junk in the tank, regardless of source, it can cause interruptions in fuel flow of course, but when it does it is more likely to be continuous vs intermittent. I would go ahead a pull the carb and do a detailed inspection and test of every component in & on the carb. This is the only way to be absolutely sure every piece is intact and fully functional. Bits of stuff that cause trouble are tiny, and usually affect the pilot system, although anything is possible. You can do it in an afternoon. The only tool other than common hand tools needed is a set of jet cleaner wires, made for carb jets and gas welder jet nozzles. Expect about $15-20 for it. |
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Title: Re: Loss of power climbing hill Post by justin_o_guy2 on 08/19/19 at 08:22:30 Fifth gear Uphill Throttle open Vacuum drops. You're lugging the crap out of it. Fifth gear at fifty MPH requires a level road and no appreciable head wind. Or huge rider |
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Title: Re: Loss of power climbing hill Post by batman on 08/19/19 at 08:49:39 Ohiomoto. I "idle" uphills doing 50 every day on my way home from work BTW. Properly jetted, this bike is a tractor at any RPM. [/quote] What steep hills in Cleveland/ Akron ? Your a flatlander ! There's no mountains in north Ohio. JOG and I are right , 50mph in fifth gear is only 3340 rpm ,the bike doesn't even reach peak torque until 3400 rpm , and only about 2/3 or less of it's hp . the bike needs to be in a lower gear, or as JOG said, your lugging the crap out of it. |
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Title: Re: Loss of power climbing hill Post by badwolf on 08/19/19 at 10:38:46 '' 50mph in fifth gear is only 3340 rpm ,the bike doesn't even reach peak torque until 3400 rpm'' I don't want to start a ''rpm war'', BUT, how can you say 60 rpm away from peak torque is lugging? Rember, everyone rides different. Not everyone expects neck snapping acceleration at all times. ( this is a mildly tuned thumper after all ) I run both Kaw pulleys and only turn 2800 rpm at 50. Seldom do I hit 4k, (but I do live in FLAT S. Fla ) I will let it drop to 40 in 5th and roll the gas on and it pulls fine. ( for me ) I am over 90k on this bike now from here to Salt Lake, Buffalo, NY, and a bunch of trips to Western NC, (I know Mo ) I think twice in W Va I had to downshift to 4th for big hills on the Interstate. (4th on my bike is almost like 5th on a stock bike) Lugging to me is when I can feel the seprate power pulses actully jerking the bike. Often that is not running the engine too slow, but applying too much throttle for the load/rpm. Yes if you require feeling the power''now'' every time you twich the throttle by all means keep the rpms up. But a big single does not live by rpms alone. |
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Title: Re: Loss of power climbing hill Post by TTom on 08/19/19 at 10:56:35 Yeah I figured I was pushing it in 5th gear. Probably doesn't help I also put on an extra 20 lbs this summer ;) |
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Title: Re: Loss of power climbing hill Post by batman on 08/19/19 at 11:30:05 Badwolf, tell me your running both kawa pulleys with a STOCK motor, I'm guessing that's not the case, which means your hp is about 27 at 2800rpm , what the stock bike might be doing at 4340 rpm at 65 mph, and you still have to down shift on a really steep grade . Why ? because the pulleys have raised your torque peak close to3500- 3700 rpm, so 2800rpm doesn't cut it. Your talking apples and oranges here. |
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Title: Re: Loss of power climbing hill Post by Gary_in_NJ on 08/19/19 at 11:40:35 The engine's torque peak is independent of the final drive ratio. You can get different results in different gears on a dyno, but that is a function of how a dyno works - not where or how the engine produces power. |
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Title: Re: Loss of power climbing hill Post by batman on 08/19/19 at 11:44:21 Gary your right perhaps I miss spoke , the pulleys slowed the motor's rpm bringing it away from Badwolf 's higher torque peak . |
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Title: Re: Loss of power climbing hill Post by Gary_in_NJ on 08/19/19 at 11:46:44 Compression ratio is fixed |
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Title: Re: Loss of power climbing hill Post by ohiomoto on 08/19/19 at 12:00:45 It's on ;D Hey batman, that hill I go up hits 14% grade. I know that because I ride my road bike up it all of the time. Sure, it's not that steep very long and it's only a few hundred feet of elevations gain, but the tractor like the power of the thumper puts right up that thing. And I'm 250lbs. It's obviously because I have a raptor petcock and my bike is so perfectly jetted! ;D ;D Flatlander my tushy! |
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Title: Re: Loss of power climbing hill Post by justin_o_guy2 on 08/19/19 at 12:40:26 Maybe it was an anomaly. Hit the hill again, same speed, same gear. If it craps out, next time try fourth. A one time thing is really tough to diagnose. I certainly wouldn't try to make mine climb like that. If it'll climb it and not crap out, I guess it was an anomaly.. If that's how you treat it, okay.. |
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Title: Re: Loss of power climbing hill Post by batman on 08/19/19 at 12:53:39 Compression ratio is fixed but only at peak torque speed , it's less before and after. |
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Title: Re: Loss of power climbing hill Post by justin_o_guy2 on 08/19/19 at 13:05:15 67647168646B313D050 wrote:
That's not the first time you've said something I don't understand. Can you offer a Readers Digest level explanation? I always thought the Compression Ratio was fixed and the result of how much of the cylinder volume is left above the compression ring at TDC. |
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Title: Re: Loss of power climbing hill Post by batman on 08/19/19 at 13:05:51 Torque peak happens because the cylinder reaches it's highest load of fuel/air mix. before it reaches that rpm the piston is moving to slow ,as it rises and the intake valve is still open and some of the mix is pushed back in to the intake manifold , after the torque peak the piston is moving to fast to exhaust all the gases from the cylinder thus leaving less room for the incoming fuel charge . either leads to incomplete loading of the fuel mix and the compression ratio is lower. |
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Title: Re: Loss of power climbing hill Post by justin_o_guy2 on 08/19/19 at 13:11:37 Well, you've been surprising me for a long time and you have an established batting average, and I don't understand how a compression ratio changes, so, if you can point me to something to read or if the explanation isn't too involved, if you wouldn't mind, I'd like to understand that. |
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Title: Re: Loss of power climbing hill Post by batman on 08/19/19 at 13:18:37 look above! that's the simple truth, there are other factors involved. |
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Title: Re: Loss of power climbing hill Post by justin_o_guy2 on 08/19/19 at 13:25:52 Thanks, I might have learned something,, I'll read it a couple more times. Thanks |
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Title: Re: Loss of power climbing hill Post by Fast 650 on 08/19/19 at 14:23:43 I think that you guys are mixing mechanical compression ratio and dynamic compression ratio, and that is where JOG is getting confused. JOG is talking about static mechanical compression ratio which doesn't change. Batman is talking dynamic compression ratio, which will change with rpm and valve timing. Just pulling numbers out of the air for an example, if you have a 100cc cylinder volume and compress that into just 10cc, that gives a 10:1 mechanical CR. That would give you about 150 psi then. Dynamic compression takes into account the momentum of the intake air which forces more air into that 100cc cylinder. That effect is most pronounced at peak torque rpm, and you may have 190 psi at that rpm which means that the compression ratio is effectively higher. Make sense now? :) |
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Title: Re: Loss of power climbing hill Post by badwolf on 08/19/19 at 14:30:05 In theory the compression raito is fixed, simple math, BUT, in real life your actual compression can be influenced by many factors way too numerous to list. I run a stock engine, other than a dyna muffler and white spacer mod. I feel peak torque at 3400 rpm does not care what gearing it is turning. 3400 in 5th on my bike is about 60mph. The stock 4100-4200 at 60 is over 70 on my bike. I read once a motorcycle uses about 20 hp to do 60 mph on a level road, no wind. Wind and hills, and streamlining make a impact on this.(as anyone who has ridden a bicycle knows) A Gold Wing pulling a trailer needs more power to do the same speed as a crotch rocket. Everyone rides a little differently. I do not try to ride fast. On the Interstate you will see me normaly in the right lane doing around 65, even if the speed limit is higher. I also avoid commuter traffic, in my experance commuters aren't driving, there ''late'' they ''can't be late'' and never seem to be paying attention to their driving or what is going on around them. On state roads I am running in the low 50's, and when the drivers that have to run ''speed limit plus 8'' get behind me I will try to let them pass. So my high gearing suits my laid-back riding style now that I have retired. I no longer have to top every hill at the speed limit plus. I ride easy and look around trying to enjoy the ride. A long trip does not mean ''I HAVE to ride 2 days to get there.'' A long trip means ''I GET to ride 2 days to get there.'' Next month I am going to Winston Salem, NC from S. Fla by way of the KSL. NOT the most direct route, but hey ''I know Mo'' If I was in a hurry I would ride my Pacific Coast up I 95 and be there in less than half the time. But it's not my Thumper. |
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Title: Re: Loss of power climbing hill Post by badwolf on 08/19/19 at 14:36:14 Fast 650 - I think the confusion is , the compression RAITO never changes, your ACTUAL COMPRESSION changes by how much air/fuel mixture gets into the cylnder. |
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Title: Re: Loss of power climbing hill Post by Fast 650 on 08/19/19 at 14:46:58 Give this man a prize. :) You just explained it better than I did, but we are on the same page with cylinder filling affecting the pressure. |
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Title: Re: Loss of power climbing hill Post by justin_o_guy2 on 08/19/19 at 14:55:36 The Bats explanation was enough for me to come to the above understandings. Thanks to everyone for their time in edumuhcating me. |
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Title: Re: Loss of power climbing hill Post by badwolf on 08/19/19 at 14:59:35 And for those who want to REALLY be confused - http://www.matrixgarage.com/content/why-dynamic-compression-ratio-nearly-useless And remember, torque is a measured number. Horsepower is caluated from that using rpm and a math formula. It was originally defined as 550 foot-pounds per second. Something to do with horses lifting weight out of a well by the steam engine guy so he could sell his tractors to farmers. |
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Title: Re: Loss of power climbing hill Post by justin_o_guy2 on 08/19/19 at 15:16:46 In keeping with most really good threads, I think this one has also gone If I may Off the Rails.. |
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Title: Re: Loss of power climbing hill Post by batman on 08/19/19 at 20:00:16 just for fun: Hp = rpm x torque ----------------- 5250 "compression is fixed but only at peak torque rpm ,it's less before and after" I was talking about both static and dynamic compression in the same sentence . sorry for the confusion. we know the static compression of a stock bike is 8.5 , but it isn't achieved until peak rpm (3400rpm) . the dynamic (real world) compression is as I stated less before and after 3400 rpm, for the reasons I stated and other factors. The fuel efficiency of the average gasoline motor is about 20 % ,that means that about 80% 0f the fuel that goes through the motor doesn't burn, that's because the fuel needs to be finely atomized to mix with air to combust , and because of slow piston speed and velocity the quantity is more important ,because quality is poor.(the reason you have a choke at startup)at speeds below 3400rpm . Above that speed the limiting factor becomes the size of the exhaust valve seat opening and the piston speed . The faster you go the more gases are left behind and the less room for the incoming fuel/ air mix and torque drops off. - |
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Title: Re: Loss of power climbing hill Post by ohiomoto on 08/20/19 at 06:05:42 5552535557554E553A0 wrote:
I had to go back and fix my last post. Hey has anyone heard from TTom, the OP that started the thread that you all took over??? LOL |
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Title: Re: Loss of power climbing hill Post by Dave on 08/20/19 at 06:42:32 So....back to the original problem. I suspect that if the bike has the original vacuum operated petcock, the diaphragm may be getting stiff. On the long climb and open throttle, the amount of vacuum in the intake may not have been sufficient to keep the petcock open and you ran out of fuel in the carb. Try climbing the hill again and see if the bike quits, and if it does turn the petcock to PRI and see if it keeps running. As mentioned previously - you should get the official Yamaha Raptor petcock (it should be around $30 and come in a white box with the Yamaha part number5LP-24500-01). If you find one that is less than $15 and doesn't show the white box - it is a Chinese copy and you should avoid buying it. |
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Title: Re: Loss of power climbing hill Post by batman on 08/21/19 at 06:24:04 Dave ,If your right and he is running the stock petcock , I think you may have it the ball out of the park! ( he could test the stock petcock in RES.) |
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Title: Re: Loss of power climbing hill Post by Dave on 08/21/19 at 07:55:42 2526332A2629737F470 wrote:
The petcock in reserve still uses the diaphragm to open/close the fuel flow (just allows a lower fuel level)......in PRI there is a metal tab that pushes the diaphragm open and allows fuel flow without any engine vacuum. |
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Title: Re: Loss of power climbing hill Post by batman on 08/21/19 at 09:07:14 Yep ment to say pri |
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Title: Re: Loss of power climbing hill Post by TTom on 08/21/19 at 12:04:15 I'm not one of this forums more mechanically inclined individuals. Isn't it a little unusual for a 6 year old bike to have a hardening diaphragm? I haven't been out on it yet on this hill but probably will this weekend. From what I'm reading, I was being a little lazy by not shifting into 4th going up this hill. Not sure if I'll be replacing petcocks anytime soon but am thankful you guys pointed to this as a potential source of trouble. |
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Title: Re: Loss of power climbing hill Post by Gary_in_NJ on 08/21/19 at 12:20:39 TTom, A couple of fact of life when owning a Savage. 1. The Petcock will fail. It can fail in as little as two years. Just because your bike is new-ish, Suzuki's inventory may not be. 2. When the petcock fails, it can present as a number of different failures. As a measure of prudence, why not change it. |
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Title: Re: Loss of power climbing hill Post by justin_o_guy2 on 08/21/19 at 12:22:15 Isn't it a little unusual for a 6 year old bike to have a hardening diaphragm? Not really. There's no pattern of predictability with them. Thing is If you ditch it for a Raptor a variable will be gone and a future failure will be avoided. When the Petcock goes south the symptoms can be confusing. |
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Title: Re: Loss of power climbing hill Post by TTom on 08/21/19 at 12:32:12 Thank you guys. This is all very helpful. It's sounds like a faulty stock petcock is more of a slow death than a quick one. |
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Title: Re: Loss of power climbing hill Post by Dave on 08/21/19 at 12:37:00 474759470A0A330 wrote:
One of the issues that may contribute to the demise of the diaphragm, is the ethanol fuel that the US uses. I am not sure the diaphragm is made from a material that is resistant to ethanol. The fact that your bike quit in a situation that creates low intake vacuum (long steep hill and the requirement for more than normal throttle) put you in a situation where the engine vacuum was not sufficient to open the gradually stiffening diaphragm. The bottom line is this the stock petcock is a problem on the Savage and it can cause problems (engine cutting out, fuel in air box and oil sump, engine running rich, poor fuel mileage).....and you just need to trust us old farts who have been around this bike for a while. |
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Title: Re: Loss of power climbing hill Post by TTom on 08/21/19 at 12:44:33 Too bad this isn't a case of the more you use it, the more flexible it becomes. :) |
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Title: Re: Loss of power climbing hill Post by ohiomoto on 08/22/19 at 08:50:49 Oh, you guys mean that it's possible that it's NOT user error or some sort of alien rpm/compression conspiracy theory??? You mean it could be the stock petcock?? Where have I heard that before?? Oh, that's right in reply #4. haha ;D |
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Title: Re: Loss of power climbing hill Post by batman on 08/22/19 at 11:40:35 That's funny ,I didn't know petcocks had worn slides. |
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