I've been through about 50 threads on similar topics, but have not found the info that I'm looking for.
I want to be able to start my bike in the first second or two of pressing the starter button. Currently it takes up to ten seconds, and sometimes a couple tries at 10 seconds each before it will turn over.
It's a 1996 GS500E, Carbs are spotless with 40 pilots, 140 mains, Dynojet needle on clip #2. I have a K&N lunchbox filter, and have removed all the carb emission stuff (it's a California bike). I live at sea level in Southern California, and it is usually between 50 and 90 degrees with a little variance throughout the year. It doesn't really matter on outside temperature on how it starts either. It can be a 50 degree icy morning and it will start the same as an 80 degree afternoon.
I just replaced the battery, which helped it considerably from before where it would barely start (I ended up having to bump start it for two weeks before I could get another battery). The spark plugs are about 3 months old and look good (not fouled at all). No vacuum leaks in any of the boots, or vacuum lines. Float heights are spot on. Bike runs great once started. I've got the warm up time down from 15 minutes to about 30-45 seconds with all the carb work and tune ups that I've done, but just can not get the bike to start like it should. It has about 45,000 miles on it now.
The only thing that I can think of is the valves might need to be adjusted. I haven't checked them yet, but the bike runs so great that I really don't think it's the valves. The previous owner said that he just had the valves adjusted a couple months before I bought it from him, so it's only had maybe 1,000 miles put on it since they were (supposedly) done.
Any help on identifying the problem, or help tracking it down would be awesome.
Sounds like a choke problem?
Does the choke open/close smoothly (i.e. is the choke cable broken or binding)? The cable may need to be lubricated. Alternatively, there may be a blockage in the choke passages in the carbs?
Not that I know of. I'll check it again, but it seems to work as it should. It only starts with the choke, and I gradually open it up as it warms up. If I open too much then it would die, so I'm assuming it works. And yes, it is moving the plunger thing in and out.
How can your bike warm up in <1 minute ? I understand it might not stall, but the oil and everything except the tires takes a while for me. The tires I'd say take 5-10 minutes, and I'm not even thinking of them.
Sooooo, mine starts first hit, usually 1/2 a second to a full 1 1/2 seconds of starter from cold in the morning. I'm about to tear apart the carbs, re-jet, adjust the valves and seafoam it, so it should be complete shaZam! by the time I'm done ;)
45K??? thats a lot.......I would start with a compression test on both cylinders, then check the valve clearances, no guarantee they were done correctly, then a plug chop at low, mid and high revs to get an idea of the jetting.
Ok, maybe not completely warmed up, but to the point that I can ride away without the choke on, and without it feeling cold at all.
Yeah it would probably be a good idea to run a compression test, too. The bike runs smooth and feels really strong, and pulls hard from 4k and up, so I'm sure there's nothing wrong with the compression, but it would be good to rule that out.
And may I ask what a plug chop is? I've done a few different tests with pulling the plugs after I rejetted, but I've never heard of a 'plug chop'
A plug chop test is a way of checking the mixture strength by examining the condition of the spark plugs. Its done at low, medium and high revs, to do it properly you need to kill the engine and pull the clutch in before letting the engine speed drop, otherwise the plug will only indicate the condition of the mixture on tickover.
This is about the best explaination I can find....... Look under Procedures
http://faq.f650.com/FAQs/SparkPlugFAQ.htm#Plug%20Chop
Great info on the plug chop. I didn't know about killing the engine at a certain place to see the mixture at that point. I don't think that would have anything to do with start-up, but that'll be great for tuning later on.
Am I right to think that it might be the valves causing a hard start-up, even though it runs great otherwise? I'll tear into the engine this Saturday and check that the clearances are in spec, but what else should I check out if that comes back ok?
I want to fix it this Saturday if I can, it's the first and last free Saturday I'll have for 18 years. My wife is going to have our baby girl within this next month and I want to get this fixed or it will never get done.
Quote from: quiktaco on February 07, 2008, 04:14:35 PM
Great info on the plug chop. I didn't know about killing the engine at a certain place to see the mixture at that point. I don't think that would have anything to do with start-up, but that'll be great for tuning later on.
Am I right to think that it might be the valves causing a hard start-up, even though it runs great otherwise? I'll tear into the engine this Saturday and check that the clearances are in spec, but what else should I check out if that comes back ok?
I want to fix it this Saturday if I can, it's the first and last free Saturday I'll have for 18 years. My wife is going to have our baby girl within this next month and I want to get this fixed or it will never get done.
WOOHOO ! Congrats man ! Kids are great ! They take care of all your excesses:
Sleep, cash, food, cash, time, thoughts, quiet days, food, cash, time, sex life (I hear those are fun, but don't remember), gs rides that are long enough to let you think "I'm bored, think I'll go home now." etc
Don't worry, she'll let you out for a ride if you look longingly at your bike enough. At least mine did. Mine actually refuses to allow me to sell our gs until I have another, you know, so I can stay sane.
Make sure and get your girl on your bike as soon as you're trusted with her outside. Pictures pictures pictures. Then, when that old bike is rusty in a shed, she can find the pics and make you clean it up and take her for a ride ;)
I think at 48k you have to expect some engine wear and slow starting is a good indicator of low compression, hence the concern. Also the fact its been re-jetted could cause problems with cold-starts if it has not been done correctly. Poor fuel flow, clogged air-filter, low spark strength or incorrect timing could also be a factor......sorry I cant be more specific, fault diagnosis from a distance is difficult.
Suzuki quote the following figures for Cylinder compression.
In normal condition 142 to 199 psi with a lower service limit of 114psi and a difference between cylinders of no greater than 28psi.
There is plenty of info regarding valve clearances on this site.
Thanks ohgood about my little one, I'm very excited.
Thanks sledge for the other info to check. I'll try to pick up a compression tester this Saturday also and see if that's in spec. What would I need to do if it weren't? Does that mean that it's time for an engine rebuild?
If you find the compression figures on the low side, squirt some engine oil into the cylinder through the plug-hole then do the test again, if the figure stays the same it indicates a problem with the top end i.e. poorly seating valves. If the figure improves slightly it indicates a wear in the cylinder and/or rings....as I said before, at 48k you have to expect some wear.
If the problem does turn out to be down to engine wear it would probably be easier and cheaper to source and fit a good condition used engine.
Thanks for the tips, sounds easy enough to test. Might just be easier and cheaper to run it into the ground then get a new bike if it's bad engine wear. It feels strong, so I don't expect it to get much worse while I have it. Thanks for the tips. What kind of oil would i use and how much. What would I expect once I start it up again? Just blue smoke from the burn off?
:laugh: at 45K I would've been glad mine started at all.
Anyway clean carbs and get compression test. You got DJ sheite, you're f^(ked. Cant change much ... lift or drop the needle is about it. BTW you prolly are lean, so check your floats, turn oout the air screws 1/2 turn at a time. If that dont work till you get to 5 turns out, raise your needle 1 clip.
Cool.
Srinath.
Cool, thanks Srinath. I know about the DJ crap. I opened up the carbs to change it to 40 pilots and 140 mains, and saw that it had been rejetted with DJ stuff. I put them in anyways, except for the needle. The dealer didn't have any in stock, so I left that. Seems to have been working out though. It's just the starting it up that's the problem. Carbs are spotless, and I'll be doing the compression test on Saturday if I can get my hands on one. Why do you think I'm lean? Because of the 140's with the lunchbox filter? Do you think it should be 142.5's or 145's? I never could find anything definitive about which to use. The matrix was slightly unclear with only the lunchbox also.
what is a lunchbox filter????
Quote from: TobySuzuki on February 07, 2008, 09:00:49 PM
what is a lunchbox filter????
K&N RU-2970
http://store.knfilters.com/search/product.aspx?Prod=RU-2970
Give it the old finger in the hole compression test with a cold engine, it's possible to not have compression seal when cold and to have it a minute or so after starting and warming. Valve clearances increase quickly as the engine warms. It's a good quick check of valve clearances, if you have cold seal and they don't get noisy after it warms up they can't be too bad.
Pull the plugs and tie the clutch lever to the grip to complete the starter circuit. Cover a plug hole firmly with a finger and crank the engine. Finger should be blown away from the hole with a loud pop. Both cylinder pops should sound about the same. Works for me, I've never bothered with a compression gage on a bike.
I don't abuse my bikes like Srinath does so passing 45k miles is hardly noticed here. :laugh: Put 80k miles on my 97 GS and son JP ran it to about 90k and then put in low milage used engine because of high oil consumption commuting on the freeway. Have about 57k miles now on my 02 GS and it still runs like new, should be good for another couple years before I start looking for a Savage. :thumb:
Thanks gsJack, sounds like an easy way to test it. Thanks for the confidence about getting high mileage on these things also. I'm sure mine will last quite a while.
I don't know what was different about this morning other than I had changed my handlebars to lower profile ones, and I had ridden yesterday, but when I went to turn it on, I turned it to prime for about 30 seconds, had the choke on, and I touched the starter, and it fired up in a tenth of a second. It was almost like I had been riding, shut it off, then tried to fire it up again right away. It was beautiful. What could have changed since before that would cause this? Maybe the choke cable is looser now with the lower bars? Maybe the float bowls aren't totally full and turning it to prime filled them, or maybe just riding it yesterday made it really easy today. I can't figure it out, and I want to make sure I know why it was so easy today, so I can keep it that way. Any ideas?
Anyone got any ideas what could have caused this? I've also noticed that my clutch is looser...engages about 1 inch further out than it used to since I got the new bars. Could that have something to do with it?
Quote from: quiktaco on February 12, 2008, 05:25:21 PMmy clutch is looser...engages about 1 inch further out than it used to since I got the new bars. Could that have something to do with it?
I doubt the adjustment of your clutch would have any bearing. Maybe it has something to do with the way the choke assembly was re-mounted? (http://bbburma.net/Smilies/headscratch.gif)