gs500 saga of endless repairs

[sikiriki]

Hello to you all,

Lurker since I bought gs500 2 months ago, member since today.

So to begin with the saga, first to say THANK YOU    for all the info I gained and will obtain I am sure.

Now a little bit of history. Some two months ago I was in a position to buy a motorcycle, searching I came across a 700$ craigslist gs500 2002 with some 24000miles under its wheels.

I got this warm feeling of joy, that only old cheap motorcycle can give you. I bought the thing.

I'll try to keep it simple and easy to read.

1) Forks.

Front wheel going slightly to the right, I tried retightening forks in triples thinking maybe they have just lided in them a little. Not.

Bought eBay forks from 2005 gs500 mounted them in old tripples, all is strait.

Bought sonic springs 0.85, When taking out old springs I found them to be exactly the same dimensions as my new springs
Left fork cap popped out stronger when removing old spring
While mounting my new So.Sp. I noticed that there is less space in left fork, so I needed different length tubes to set the preload to the same 3/4"

Difference is unbelievable. I did not changed the oil. Just took old springs out. I am lazy.

There is less dive. I have not checked the sag, I am lazy.

Front now "talks to me", i can feel what is going on with the wheel, and I noticed that rear shock is awfull, soft and bouncy.

I have put less preload than there was with old springs.

I guess something is strange but I love how front is now, I will play with oil and preload later. But basically as far as my driving goes this is perfect.

Any thoughts on different lengths of spacer, needed for forks. I thought they will be the same.

old forks


old spring and spacer up. sonic and longer spacer in right fork leg, down.

[sikiriki]

So, since I have obviously bought my self a set of similar springs, just set the preload righter than pour soul before me we go to item no.

2) Engine

   700$ in usa for 2002 gs500 means a lot of rust and a pool of oil under the engine, no starter to start the bike, but a hill in San Francisco that is used instead.

3 weeks later and there is new starter clutch in the bike, old assembly ate the 3 bolts that hold the clutch to rotor, and with my strong  thumb i broke off the magnet from rotor, so new rotor in everything bolted, threadlocked and driven for 2000miles or so. No problemo there.

But, there is a lot of particles having party inside the engine.
Being a good owner that I am I decided to check the head, valves etc. Not like the previous heartless owner

I found tight exhaust valves and set them properly, except right ex. I went from 2.65mm to 2.35mm shim, still tight. Can't  even turn the bucket by hand. Ordered 2.15mm and searching for bmw gs650f shim that goes to 2.00mm and will fit gs500 bucket. compression is good, checked by thumb in the sparkplug hole method. By good I mean still there, but I like to think it is good. I say it is good 1220 times a day, and so it is true

Now, I have taken ru2970 and mounted it. Cleaned the carbs (not good, I think), balanced them by my mighty eye and put 20/65/142.5 jets in.

A lot of playing with float levels, and idle mix screw leads me to believe that 20 pilot jets are just too big. It pops trough exhaust up to some 3k rpm from where it works perfectly. Since I got it it worked good above 3k rpm. below however. no power. i believe pilot circuit is clogged on right carb. sparkplug is whiter and when I start the bike right cilinder is colder, if warmed up above 3k rpm it heats up same as left:D  but there is that ex valve?!?!?

I have found deep groove on left ex camshaft lobe, but the side that is opposite to peak (part that pushes the valve), journals have markings, and It is basically not a happy head.

Few questions. Does anyone know of shims smaller than 2.00 for gs500, non grinded? short search revealed klr, gs650f and some rotax machines hawing same shim sizes.

I will probably  buy ex. cam. and journals but after I confirm I can use the head with that damn valve. Anyone has any offers?

Pilot screws all the way in and engine still working even with floats set high(low fuel level) mean to big pilots?

I have set the timing using manual and beergarage photos. All the markings on camshaft sprockets aligned, 18th link to intake cam etc. and I end up with a slight retardation of timing. Around 2 degrees on camshaft. I have popping now trough carbs. slight. trough cali. emission stuff on carbs. If I go advance on camshafts, it will be around 3-5 degrees. I thought less difference from ideal is better. Am I that wrong?

I know I did too much stuff at once, I know first thing is to set the valves and go from there. 2.15mm Shim is in the mail, and I am driving  the thing every day. popping and driving people around me crazy. K&n ru2970 is definitely too loud, but it makes the bike go happily.

Now I am going to set the floats to 14mm, and put 17.5 pilot in. As I am deeply in setting this bike up, confusion is ever present and I appreciate any thoughts.

In the end, I will end up with some parts that I will sell cheap or give, somebody can learn something from all this, and I will end up with a finely tuned little bike. I say that 1220 times a day

thank you.

[Phil B]

Wow... for all the work that you've done so far, and sounding like all the work to come, it sounds like you paid too much, $700 for that bike!

But I have to say, I admire your wrenching spirit

[sikiriki]

Well, yes I did  but no biggie. c' est la vie. It's an old machine and serves me well. I did around 1700miles in about a month. So it has my sympathies. It wants to live.

[BockinBboy]

The symptoms you describe such as the popping and white plugs, are a lean condition.  You are all over the bike, and you need to start and finish with one thing at a time.  I know you know this, but maybe you need to hear it from someone else. (so there it is). 

To start off treating the lean diagnosis, you need to start from the beginning and work your way to the end.  Start with your fuel tank.  Make sure adequate gas is leaving the tank (fresh fuel is a must!).  Tank petcock all the way on?  Then go to the frame petcock.  Make sure all the gas that came from the tank is getting through the frame petcock (Try running the bike on Prime, then switch to On. Does the problem change at all in either position?).  Then go to the carbs... 

There is plenty on the forum of this process and what should be done before others.  If you don't go in order and finish each one, your possible fixes will get you farther from solving your problem.

It sounds like you have the skill set to get this bike going like a treat, just don't get ahead of yourself.

Good Luck!

As a side note: Does the K&N RU-2970 come with a restrictor? If it does, put it in if it its not on there already!

- Bboy

[bombsquad83]

I believe that's the "lunchbox" filter, so no restrictor.  Definitely needs a rejet when using that filter.

[sikiriki]

thanx again,

yes, ru2970 no restrictor. as far as I have noticed it is as there is no filter at all. fuel lines to carbs are ok. prolonged high rpm even with larger jets and lower fuel level in the bowls is ok. There is something wrong with the pilot circuit- i just have a feeling .

first thing is first. i vill pull carbs down put 17.5 pilot jet and set idle mix screws between 1.5 and 2.5 and set floats to little more than 14mm  I believe it will be significant improvement. will get back with the results. thorough cleaning I'm postponing for when i set the valve, that is my main concern.


And camshaft timing. should I advance it? I notice no popping now(carb popping), but I have been just riding it, and that k&n is just loud as hejj.

one last thought before I go. Do you guys believe ru2970 makes lean condition even when jetted properly in sudden WOT situations. being so free flowing?

[sikiriki]

ok, can I say success before I test it.

i have pulled the carbs apart jet again. found hair in float bowl. took 2 little screws that point toward engine intake out. it says 160 on them. is it right. set the floats to 15mm, that is the value bike is happiest with and put 17.5 idle jets.

Bike now starts easier, mix screws are 2 turns out. will set them at 2.5- 3, and I will set them properly once I set the valves right, and balance carbs. For now it is good.

i hear popping, but there seems to be misunderstanding, I had loud explosions before, coming out the exhaust. Now it is just popping sound. Waaay smoother power. both cylinders heating more evenly now. i think I just need to set the mix screws properly.

So here it is. 17.5/65/142.5 with lunchbox and stock exhaust for me. I'll confirm it later, when I set it up and do some miles.

I did some thinking about what I asked earlier, and I believe yes. Lunchbox makes mix lean if you turn the throttle open suddenly. it is the point of the carbs, to run between rich and lean, and make the machine go, and when you put something like ru2970, you upset the balance:)

but I think I like it more and more. If you want to run it slowly and silently you can, and if you want to go, it gives you feedback of how much throttle engine can take to accelerate fully. It makes machine more direct.

well enough of thinking outloud.

I still need advice about timing. should i advance the timing or keep it retarded. difference is one link on camchain. It would be more advanced than retarded, compared to ideal.

thnx.

[weedahoe]

just curious, where are you located?

[Janx101]

his second post mentions San Francisco .. but that may be the origin of the bike only?

[sikiriki]

I'm in San Francisco.  Tested the bike, although better, it is still bad. no power until 3.5k but now only until itheats up. still cold on right cyl. whn fired up. When wormed up, it gains power down low and goes crazy with rpm, idle screw is useless.

Is it possible that the only thing that keeps it alive is its wide aircooled tolerances, and it gains some space when everything is warmed up. def. need to wait for that shim now. hopefully 0.2mm drop will open it up.

it's a tough little machine, I can say that much.

[sikiriki]

Shim arrived, I installed it and there is clearance. .076mm with 2.15mm shim wooo hooo fcuk yeah

I know this, but one should NEVER! try to set up carbs 'till everything is right with the bike.

Immediately   bike sounded different. I was basically running it on one cyl. back with 20 pilot in it. Around 2.5 turns of idle mix.

I still have popping trough carbs. No popping trough exhaust. It blows trough cali emission holes on carbs.

Is it cam timing? I really need some opinion on this. I checked it again and all is by the book. it is slightly retarded, but it is soooo small.
I will advance it, but in around 2k miles when I check the valves again.
Can it be something else? I really have no energy to pull everything apart again.

Just to write it again: I bought the bike and drove it for 1500mi. checked the valves and all of them were tight, right ex. couldn't even move the bucket. shim was 2.65. 500 miles with 2.35 shim, and now 2.15 gives it .08clearance.  I am amazed, more than 2000miles of TIGHT! valve

Fcuking granite these
machines 

so happy now 

all the best to you riding world



 

[bombsquad83]

I'm confused.  You say that you did it by the book, but the timing is slightly retarded.  So which one is it?  I'm sure Adidasguy has some pictures of how it should look.  He had a similar issue on one of his bikes with the timing chain.  If you are talking about the timing chain, this affects more than what you would normally call "timing".  Timing is when the spark plug fires in the cycle.  If the chain is off, you are changing the timing of the valves moving with the piston.  You always want the timing chain to be "by the book".

Glad you got it running!

[sikiriki]

Sorry for bad explanation, it is camshaft timing. I aligned markings on pickup (r-t on left pickup) mearkings on exhaust cam should be 2 at 12 o,clock and 1 parallel with head gasket or 3 o'clock. 18 pins on chain and than intake cam. When I do it that way. Marikin no 2 on ex cam is some 2 degrees to the left. If I would to use next link it would be some 2-3 degrees to the right, hence advanced. When I took it out It was advanced. I needed to take it out, couldnt move buckets how tight it was.

I am happy with the performance, only thing is that popping trough intake, when it happens  it drops rpm when idling, and I guess it will break carb. diaphragms.

It is a tiny amount of retardation. But I can't explain it any other way. And it happened when i did cam timing 

Intake valves are set at 0.04mm. Tight but ok.

Never messed with ignition timing, and it looks to be not tempered with.

[bombsquad83]

Are you checking the timing chain with the tensioner tight?  Maybe a picture is in order...

[sikiriki]

When assembly takes place no. I try to make part of the camchain that is in front of the engine tight as possible. I honestly do not see how it would be possible to fiddle with cams while tensioner is on. I check it with everything assembled though. Double check it. Tensioner in place. I assembled everything now. Can't take pics now.

This one is from beergarage and is more advanced than mine is retarded, as far as I can see

http://beergarage.com/imgs/GS/Timing/92.jpg

[sikiriki]

It looks the same as mine actually. Mine is set one link back.it seems more right to do so. Now it pops 

[sikiriki]

hello people.

I have a set of forks (pictures in the beginning of thread). some stiffer springs. same dimensions like my sonic 0.85. some parts of starter clutch (clutch star, rollers, pins and 2 springs, big gear with bronze bush.) rotor with broken magnet and bolt bodies inside bolt holes. sheared.

I am looking for custom valve shim. 2.10mm. fork bridge. stronger. not oem. and katana 600 spring.

willing to put some cash. trade. etc

[BockinBboy]

Make sure you post over in the For Sale/For Trade Section of the forum. 

There actually is a member who had a bunch of stronger fork braces made.  It seems there may be a couple left.
http://gstwins.com/gsboard/index.php?topic=57028.0

Post for the shim over there too.  Someone may be able to trade you or you can buy one outright there.

I would post a WTB for a katana shock over there, too... but being as they are a popular upgrade and usually get sold quickly, you might be suited to just look on ebay for that.

- Bboy

[mass-hole]

Don't worry, even when you do fix the major things, it will still require fairly constant attention. my bike is bone stock except for springs and an R6 rear shock and its always something.

I spent last winter doing a full tear down on my bike. I took it apart piece by piece, cleaned some of the stuff you couldnt get to otherwise. Cleaned out all the suspension bearings and regreased, re torqued every bolt to factory spec when rebuilding. It was quite fun and the bike did ride better after.