Yet again my bike doesnt want to act right. I was riding to work today and was at full throttle on the highway and topped out at 75-80 mph and it took a good 5 minutes to get to 80 and the popping is now back. Ugh this bike has been a headache i really dont want to take it to a shop but its starting to look like i may need to.
did a valve check 4k miles ago im going to do another one hopefully that is the issue.
What does it do if you try to ride those speeds in 5th gear? Do the problems start at the same RPM, or do they start around the same MPH, or completely different?
more details...your description is way to um... vague
what gear?
what RPM?
jetting?
pipe?
did you let budduh touch the carbs? :icon_rolleyes:
I had similar problem..turned out to be tear in carb diaphragm
it was topping out at 6000 rpm 6th gear
Manoj
I have the same problem on the interstates going up hills. Bike will be cruising at 75 at 6,000 RPM in 6th gear, than will hit the hill and it will just slowly start to decelerate (with full throttle). Usually by the top of the hill I'm at 65. It's intermittent though. Some guys told me to check the ignition coils/spark plugs. I will see if new plugs do the trick.
Sorry for the lack of info. I was very angry at the time of posting cause i thought i had fixed the problem. I may have caused it myself by putting a inline fuel filter on the bike which might be the cause of my problem. Lets see, i was in 6th gear at about 6k rpms and it doesn't go much higher. Fuel throttle in 5th gear bumps the rpms up more of course but still have the lack in power and tops out at about 80. I replaced my fuel line due to the fact that i accidentally ruined my old one putting the inline filter on. Now i read that its gravity fed and maybe the cause of my issues. I'm going to try to top it off today and see if i get better performance due the the extra gas weight. If no change ill pull the filter back off, though i already spotted crud in the filter after just one day of use...
If you noticed some gunk in the filter, does your tank have any rust in it? Some of that may of ended up in the carb's and could be giving you some performance issues. Are the plugs in good shape? Might want to check the float height. If set to low it could be lean at top end. Have you gone through the carb's lately?
i just replaced the plug, and cleaned the carbs and jets. I have to get some hose to check the float height.
The plugs you took out. Were they white looking(lean condition), black (fouled) or a nice shade of grey.
plugs showed no unusual combustion. I remembered that i didn't engage my gear all the way a few times when i was having fun in the twisties and over revved past 11k id say a good 4-5 times since my last valve adjustment. The best way to describe what is happening is this. Its like trying to ride without letting the bike warm up and for some reason the bike ALWAYS misses without a pop at 45 mph no matter what gear that i am in. I hope that helps some cause i think ive check everything else out besides carb syncing and valve clearance...
It's amazing what a good carb synching will do...
Does it hesitate (too lean)?
Or, surge (too rich)?
How many miles since the last valve adjustment?
my bike has been experiencing fuel starving past 80/85...it splutters to 100
I recently changed the fuel line,used 1/4 inch ..is this the recommended size for GS
and installed inline fuel filter on both fuel and reserve line
would any of these changes cause fuel starvation other than petcock
and which direction the arrow of the filter(Autozone ) should be facing
Manoj
it hesitates. It seems too lean. Someone that went riding with me suggested i sync the carbs as well. Do you think this is the problem? I wouldnt hurt to check. Wheres a place to get a decent carb syncing tool btw? Its been 5-6k miles since last valve adjustment i made a mistake before heh. Bad memory i have it written down for a reason lol
ok i think ive been making a huge mistake this whole time. The large screw between the carbs is only to adjust the idle and not the fuel air ratio correct? Then i have not messed with the air/fuel in the carbs at all and i feel like a moron if thats the issue. That is if my bike is running lean... If someone could point out where the screws are, i think i have a idea but i dont want to mess with them if they are not. I apologize to everyone thats been helping me.
That knob only affects the idol. The mixture screws are under a brass cap on the underside of the carbs.
any tips on removing the brass cap?
paraphrased from the wiki: drill it, work a screw into it and pull it out.
http://www.angelfire.com/mt2/mikesgs500/rejetting/
pictures! =]
they are removed, everything back together warming up at the moment... Now for adjusting. =D
havingf the worsdt time trying to adjust these where they are
you need one of those little nobby screwdrivers that are only like 3 inches long.
you know the cheap screwdrivers with the exchangeable tips? use just the tip, thats what I did, and it worked fine
I messed with it for a good hour lastnight. I screwed them both in all the way then 3 turns out, still popped. Then some fine adjusting and i still had popping so im not 100% sure whats going on but im going to get a carb sync tool today and some tube to test the floats.
Wish I could have responded yesterday.
The most important thing to do every 4000 miles is to check the valves, as these will affect the carb synchronization.
1. Check valves
2. Set mixture screws
3. Synch carbs
Synching the carbs before you do a valve adjustment, means you will have to do a carb synch AFTER the valve adjustment.
ok thanks, this will be my first time tearing into the valves i paid a stealership to do my valves last time. this should be a experience
.038 doesnt fit under any of my lobes... i think they need some adjusting
have no idea how to get the shims out without a shim tool.
Quote from: Jlittle on April 27, 2010, 01:04:51 PM
have no idea how to get the shims out without a shim tool.
you can unbolt the cam bearing caps and lift the cams up. just make sure to measure everything first so you know what clearance you need to get to. then lift the cams up, get the shims out and measure them. once you get the shim thickness, go up or down sizes depending on the clearance you need. good luck!
But be careful not to allow the chain to move across any teeth or you may bend a valve.
Before unbolting cam caps, make sure to turn the motor to Top Dead Center (TDC) and look at the cam markings so you can line up the cams with the crank when you bolt them back up. And, be careful unbolting the camcaps so you don't bend a camshaft.
my shim sizes are 262, 268, 268, 280. What would the shims sizes down be?
They're available in .05 increments.
So:
2.60 2.65 2.65 2.75
Or, if you want more clearance:
2.55 2.60 2.60 2.75
i think mine are smaller than they are labeled. I got some from the local cycle shop for free and they were a step down and still couldnt get a feeler under it so maybe it was worse. I will measure them tomorrow, ive been bickering with the bike for over 5 hours now and am going home. lol Thanks for all the help guys. I dont know how yall do this every 4k miles hahaha.
just keep at it friend. im not sure mine are spot on either, but i messed with it for at least an hour.
You should measure the shim thickness with a caliper, don't go by what it's labeled as.
guess what guys... its done and everything looks good to go after 2 more trips to the bike shop. Putting it back together now. Then i guess fuel/air tinkering?
Quote from: Jlittle on April 28, 2010, 11:54:55 AM
guess what guys... its done and everything looks good to go after 2 more trips to the bike shop. Putting it back together now. Then i guess fuel/air tinkering?
COGRATS! haha
im still working on the pilot mix screws and float heights. stuck at work though so cant quite get to the good stuff.
Thanks, it feel 1000x better than i did this morning before comming in to work on it. ugh lets hope i didnt mess anything up in the process lol! Good luck on the jets, ill be rejetting here in about a month or so.
cleaning and rejetting is easy. it's the adjustment that's difficult. the whole process is slightly subjective. so go with what you feel is good. =]
im warming my bike up to adjust the air/fuel now and its poping quiet a bit just warming up. I have it set to 3 turns out. Is it in to lean it out to richin it up?
Considering the screws are mixture screws, they allow both air and fuel. But, the more you turn them out, the richer the mixture.
Popping - The valves are all within spec? Float height set properly?
How is the throttle response?
the valves are now, i pulled the plugs and they are a bit wet which means a little rich which doesnt make sense. Im gonna take it for a run around the building to see whats up.
just took it for a spin around the block, didnt get up to highway speed but i can def tell the difference after the valve adjustment. The response is a little laggy, and just pulled the plugs and they went from being wet to a little white.
Throttle position determines which jet is supplying the gas mixture.
(http://justkdx.dirtrider.net/images/graph.jpg)
Here's some good general carb info:
http://www.xs11.com/xs11-info/tech-tips/maintenance/carburators/68-tuning-carbs-by-reading-spark-plugsthrottle-chop.html (http://www.xs11.com/xs11-info/tech-tips/maintenance/carburators/68-tuning-carbs-by-reading-spark-plugsthrottle-chop.html)
Lagging under load...if that means that it bogs while under acceleration, it's too rich. If it hesitates, it's too lean. This also, assumes that you are riding at or above 4000-4500rpm, anything below that it will lag anyway.
I should have been more specific in my question: How is the throttle response in neutral? If you can whack open the throttle and it does not hesitate to send the rpms up, then your carburetion down low is good. If it hesitates, it's too lean.
it is below 4500 so im gonna assume its normal. Im gonna ride home tonight to test it all out and we'll see if the popping at 45mph 5000 rpms still happens. Thanks for all the help guys.
Well I took her home lastnight. Massive improment in the feel and I heard a weird noise then realized that it was what the motor used to sound like when I got it lol. It still pops loudly on occasion during takeoff. It dimishes greatly after its been riden for a little but still there. I'm currently 3 and a quarter turns out on the air fuel screw.
If you've been riding with the valve clearances too tight for a while I'd suggest doing a compression test. You may have a leaky valve.