GStwin.com GS500 Message Forum

SO, today at lunch, I hop on the bike to run to an appt. I choke it as always, give it a few revs, take about a minute, and choke it down...seems to be idling fine, getting fuel, so I go. The entrance to the freeway is about 200 feet from the building, so I hop on...merge on over to the carpool lane, and get up to about 75/80. well about a mile in, the motor starts bogging down, I immediately check the fuel valve, switch it to RES, but it doesn't help, the oil pressure light blinks a bit, the bike slows (I have a big Chevy pickup on my ASS), and then I have to pull over on the side of the carpool lane..luckily there was a emergency cross over right there, so I could get over...but I let the bike sit..then cranked it a few times, it turned over, and all seemed normal...I sat there for a good 4.5 minutes letting it run before I took off again.
I'm assuming this was just my mistake, not letting the oil pressure get up to where it needs to, before going that fast? The oil level is fine. Man, it was NOT fun having the bike just quit going 80 mph in the fast lane.
Lesson learned. :oops:

I dunno.... I've done almost the same. As long as  you don't give it too much gas it should be ok.  Don't rev it too high either, if it's cold don't go higher than 5000-6000 rpm

I have never had a problem hopping on the freeway before it has fully warmed up. Maybe because the freeway is a little farther for me.

that sounds like the fuel starvation problem that others have experienced on this board.  You might do a search on 'fuel starvation' and find out more.  It has never happened to me personally, but it has to do with the bike temporarily starving itself for fuel at hwy speeds.  It is said to clear up in a minute or two.

Look at this thread  http://www.gstwins.com/forum/viewtopic.php?t=9309&highlight=fuel+starvation

yeah i always take off before the bike is fully warm, i don't have all day to sit around and let it warm up fully all the time.  i've experienced something like that when i forgot to turn the choke off after the engine was warm.  if the bike warms up, and the choke is still on, then what you experienced might happen, perhaps that was your case?  make sure you turn the choke off after a suitable amount of time.

The oil pressure should have been fine.  You shouldn't get an oil light when taking off after a "short" warmup.  As for the no power thing, it was probably your choke being on and the engine being warmed up.  The only problem I ever have by not giving it a nice long warmup is it will idle REAL low and I have to keep gooseing the gas to keep it going when stopped.  I could probable avoid that by playing with the choke but I don't bother.  I give it a minute or two of warm up, then take off and close off the choke as I leave the driveway.  Runs pretty good too.

whats a warm up time? :dunno: Oil pressure usually builds up quick...like with in 20 seconds of starting I'd say. Even my dad's big diesel truck's oil pressure builds up in less than 30 seconds. In the mornings as I rush to get ready for work I usually only give it one crack to get it started and don't even use the choke. It bogs down a lil because its cold but then its fine.

I usually start it, then give it 15 seconds for every hour it sat cooling (up to 2 minutes max).  It's about 4 blocks to the freeway, and haven't had a problem.  But I usually ride those 4 blocks in 1st/2nd to keep the RPMs between 4k and 5k.

Also, there is a stop light before the freeway, and if I get stopped, I'll put the bike in neutral and hold the throttle to 3k RPM while I wait.  

Which reminds me: can anybody suggest whether the bike will warm-up better if the choke is keeping it at 3k RPM, or the throttle is keeping it at 3k RPM?  It seems to me that it shouldn't really matter, so long as the engine is running.

only once have i had an issue as you discribed, it was due to water in my tank. took abit to work past everything to get into the float bowls.  then it wouldnt rev above 4K before spudering.  Every day i back out, switch on, press the starter, rev rev rev, kickstand up, clutch shift go. just that quick.  all less then 1 min from backing out.

I had just the situation you describe happen once during a 230 mile ride. The bike tried to die(fuel starvation :dunno: ), I shifted down to fifth and backed off a bit. It smoothed out and I left it there for the remaing 25 miles to home. It hasn't done it since, but if it happens again, I'm switching it to PRI position to see what happens. I doubt if it was choke/warmup related either. I let mine idle for 1 minute then ride 3-4 miles with the choke partially on before shutting it completely. Never had a problem. Good luck and try PRI if it happens again. :cheers:

take off the carbs, drop in a 40 pilot andyou will never have warm up longer than 30 seconds ever again.  I used to smoke a cigaetter while i waited for mine to warm up in the morning, now I don't even have time. Moral.... 40 pilots are better for my health.

Jake

I take off with the choke on enough so that it'll idle at about 1200 then take off the choke a couple of minutes in the ride.  Seems to do the trick, no bogging or hesitating.

If the fuel starvation keeps happening at high speeds and nothing else works, make sure the valve on the bottom of the tank is fully on. I was about to tear the entire fuel system apart after this kept happening to me, then I saw the valve was only half-on.  It has to be cranked fully clockwise until it stops.

Quote from: joerockerI give it a minute or two of warm up, then take off and close off the choke as I leave the driveway.  Runs pretty good too.

hmm, me too....  :?

I just close the choke as I pull out of my driveway. Then agian, I go a mile or so at about 40 before I get to highway speeds.  :dunno:

What year is your bike?

I've a 96 and have had the fuel starvation thing happen repeatedly. the first time was about 160mi into a 220+ mile trip, then about every 40 miles thereafter. wierdness to the max. it happened on hard acceleration today IN TOWN, which sort of goes in the face of the "highway only" supposed nature of the problem. I've heard that the problem is the petcock. when it happened today, I switched it to PRI and it fired right back up. maybe it was in my head, but it felt like it ran a bit smoother too.

as for oil pressure, that should build up right away. I've always looked at warm up time as going easy on the engine until the oil has reached operating temperature. before that, it's not lubricating as well.

btw and not to distract from the topic at hand, but is it okay to leave the bike in PRI?

-Riz
:thumb:

I have a somewhat similar issue.  If the engine is cool, I noticed that if I hit the throttle hard, the engine loses power and sputters.  This is sort of a problem for me because I have to go three blocks and then jump on to a road going up hill which drivers travel at very fast speeds.  If I don't wait long enough, well, I could die, and of course, I don't really know how long to wait.

jake42, could you please elaborate on the 40 pilots business, keeping in mind that I'm a n00b.  Maybe that would fix my problems.

Thank you.

Smooth Dave

Quote from: SmoothDaveI have a somewhat similar issue.  If the engine is cool, I noticed that if I hit the throttle hard, the engine loses power and sputters.  This is sort of a problem for me because I have to go three blocks and then jump on to a road going up hill which drivers travel at very fast speeds.  If I don't wait long enough, well, I could die, and of course, I don't really know how long to wait.

jake42, could you please elaborate on the 40 pilots business, keeping in mind that I'm a n00b.  Maybe that would fix my problems.

Thank you.

Smooth Dave

\

Dave,
Do a search on jetting and you'll see that the 40 pilots are recommended to get rid of the long warmups.  I"m pretty sure I'm correct on this, but the pilot jet controls the idle circuit and since these bikes are jetted lean coming from the factory, the 40 pilots will richen the mixture up enough that you don't have to wait forever for warmup.  For example, my bike now  on full cholke will warm up in about 30 seconds.  The only thing i'm not sure of is what effect if any changing pilots only would have on your air/fule mixture.  When I did mine, I rejetteed the pilots and main because i put on pods and a new pipe, so I had to reset the air screws to 3 turns out.  None of it is really hard to do.  You may want to get Srinath or one of the other carb gurus to weigh in on whether or not you need to change the mixture if you're just dropping in pilots.  By the way mine cost a total of 5 bukcs from my local shop.

jake

Quote from: Mike HarmanIf the fuel starvation keeps happening at high speeds and nothing else works, make sure the valve on the bottom of the tank is fully on. [...] It has to be cranked fully clockwise until it stops.

First sentence - GOOD.
Second sentence - NOT so good.

Here is a (kinda small) picture of the tank-mounted petcock from the right side of the bike:


The valve is ON when the slot is in the vertical position (as shown).  If you turn the valve to the "stop" in either direction, the slot will be horizontal and the valve will be OFF.

Any position between vertical and horizontal means that the valve is only partially ON.

Thanks for the feedback everyone. After reading the points, I'd say it was a fuel starvation thing. Now that I think about it, the oil pressure light only came on when the engine died...as it always does. I have a '97 which has a V&H and has already been rejetted-and most mornings I only wait about a minute or two before taking off..just making sure to keep the throttle up a bit when stopped so it doesn't die.... :dunno: so I think I need to check the petcock valve under the fuel tank.