Intro, idle and other questions

Batan · July 09, 2008, 04:08:05 PM

Hi everybody. My wife and me just finished a motorcycle course and are starting to get into motorcycling. I went for a first official ride today on a GS500F I bought as my second first bike, LOL. Second first because I got two as there is two of us. A couple of months ago I bought an 82 CB750F, but have not ridden it yet as I was waiting for the course. Not too many used GS500s around Vancouver(Canada) area as they are the bee's knees of beginner bikes and usually sell quick and are often overpriced. So, I bought the 'F' and continued search, my plan was to get a GS500 eventually and I lucked out a couple of days ago which was great because we just happened to finish the course last week. This way I can ride the F when we're both riding and GS when I'm alone as it is a lot lighter then the Honda. Anyway, here are bpth bikes:

Not the best shot(cell) above, but here's a good one of the F:

Anyway, the PO put $1800 into the GS500 within last few months(have bills) as it needed various gasket done and other stuff. I see a charge for "cylinder block machining" but no rings which makes me think they machined it for head gasket to seal well. Tank was done as well. Apparently they went through carbs as well although there is no indication on the bills. Doesn't matter, one thing that happens now is, the RPMs don't want to drop. They hover around 3500rpm and sometimes will drop to idle after few seconds at the light but just sometimes. It's a PITA to ride it that way as it acts like it's got cruise control that would not shut off.
As for choke, I don't know if this is normal but if the knob is tuned all the way in "on" position, it will kill the engine, hot or cold. However, 2/3 or 3/4 of the way in the choke seems to function although after a couple of minutes, if I want the RPMs to go higher then 2k, I have to give it some throttle with the choke on. In that case they will climb to 3kish and stay there. So, all in all, choke seems to be functioning but let me know if any of this is abnormal. As I don't have the owners manual, I have a few questions:

what should the idle be at?
what should the chain tension be?
Of course any input on the RPMs not dropping is very welcome. I did find that couple of threads on it but not much info other then to set idle after 15 minutes of riding. Thanks everybody!

ben2go · July 09, 2008, 04:18:05 PM

Idle should be 1200 rpm.

Chain slack .75 to 1 inch or 20mm to 35mm.I think that's the correct metric slack.

Batan · July 09, 2008, 04:24:13 PM

Quote from: ben2go on July 09, 2008, 04:18:05 PM
Idle should be 1200 rpm.

Chain slack .75 to 1 inch or 20mm to 35mm.I think that's the correct metric slack.

Thanks. Well, idle seems to be set right. I went downstairs again as the bike was still warm to check the idle. And BTW, the bike is a 1994 as I seem to have failed to mention that.

GeeP · July 09, 2008, 04:31:32 PM

Looks good! Nice Honda CB too!

BUT! You MUST ditch those archaic pedally thingies, they're taking up waaay too much valuable motorcycle space in your garage.

Batan · July 09, 2008, 04:36:09 PM

Quote from: GeeP on July 09, 2008, 04:31:32 PM
Looks good! Nice Honda CB too!

BUT! You MUST ditch those archaic pedally thingies, they're taking up waaay too much valuable motorcycle space in your garage.

LMAO...good one. it's the underground parking in my building.

Another question, is it normal for floating disc to make noise when going over bumps at low speed? It's a bit annoying, sounds similar to when the front pads on a car are miossing anti-rattle clips.

commuterdude · July 09, 2008, 04:56:40 PM

Nice GS....THAT IS A BADASS HONDA! DAYUM!

Batan · July 09, 2008, 05:14:08 PM

Quote from: commuterdude on July 09, 2008, 04:56:40 PM
Nice GS....THAT IS A BADASS HONDA! DAYUM!

Thanks.

I managed to find some threads on the idle(hovering idle) issue. Is there any links to an online manual? As I mentioned, I don't have one so I've got no specs on anything. Over at CB forum, they have it available in PDF for the CB750F, LOL.

GeeP · July 09, 2008, 06:02:29 PM

As far as the RPM not dropping, the choke not only enriches the mixture, but increases the engine speed as well. If it isn't all the way in the "off" position, it will increase the engine speed. If you still have a problem, you might try pushing in the choke plunger rail on the carbs to make sure it is seated fully. Somtimes they stick.

GStwins member Prafeston had the manual available online last winter. I don't know if he's still doing that or not. I'll try to remember to IM him the next time I see him online and ask.

My GS makes a clack or clunk or something going over hard bumps, always has. I never really have bothered to look for the cause, as it is well maintained. I suspect it is simply a resonant frequency of the forks.

Batan · July 09, 2008, 06:34:32 PM

Quote from: GeeP on July 09, 2008, 06:02:29 PM
As far as the RPM not dropping, the choke not only enriches the mixture, but increases the engine speed as well. If it isn't all the way in the "off" position, it will increase the engine speed. If you still have a problem, you might try pushing in the choke plunger rail on the carbs to make sure it is seated fully. Somtimes they stick.

GStwins member Prafeston had the manual available online last winter. I don't know if he's still doing that or not. I'll try to remember to IM him the next time I see him online and ask.

My GS makes a clack or clunk or something going over hard bumps, always has. I never really have bothered to look for the cause, as it is well maintained. I suspect it is simply a resonant frequency of the forks.

Thanks, manual would help.
As for the noise, I'm pretty sure it's the floating brake disc. I checked around and it seems like it's relatively normal for rivets to have more slack overtime. For example, here's a similar thing on a GSXR:
http://www.youtube.com/watch?v=_K-4pQvEiag&feature=related

I will have to check the choke and throttle cables as well as spray some WD40 and see if I;ve got any leaks ...

Batan · July 11, 2008, 05:54:51 PM

Ok, well I tinkered with it a bit today, not a whole lot as my wife wanted to go for a ride but did try to check a couple of things. From what I can see, I think the choke does go in and out properly when it comes to carb side. However, it does not work as well as on my Honda, needs help from the accelerator to bring the RPMs up and it's more of an on/off then anything else. Meaning, I can't seem to regulate the cold idle much, the choke keeps it at 3-4k and it's either that or normal idle speed.
I also sprayed WD40 on and around the carbs to try to locate if there is a vacuum leak but did not find any.
Warm idle is to spec, I adjusted it yesterday afternoon and juding form my wife tells me, as I did not ride it today, it might have shaved off some of the annoying idle hovering but it's still present.

Man, the carbs and intake boots on the CB are a lot easier to access.

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Intro, idle and other questions