Hi Guys,
I've been lurking on this forum for a while since buying a 1998 GS500 a few months ago. I've found the forum invaluable so far and have fixed many common-ish problems based on past posts, so thanks!
Anyway this one seems to be specific to my bike so here goes:
The bike came to me with a drilled out stock exhaust and individual "pod" filters. No jetting changes had been made, but I used the information here to set that right and got the bike roadworthy.
I had a problem with WOT though - the bike would sort of "hammer" or "stutter" almost like it was running out of fuel, and nothing I checked/changed would help. Finally on a whim I blocked off one of the holes on each of the carb slides and this did largely solve the problem.
Everything I find on here regarding slide restrictors relates to the pro's and con's of Dynojet needles – I'm 90% sure my needles are stock so the question is:
Are my pod filters causing my slides to flutter badly or is it possible that there is some other issue that needs addressing?
BTW pods filters are my only option – I've tried refitting a stock air-box but the PO grafted on an SV650 back end, seat and tank so now it wont fit.
Thanks Guys
Chris
Well, ive had problems with pod filers, myself in plenty og gs' past. I ended up using a k&n lunchbox. might be an option if whatever is suggested here doesn't work?
Have you tried running the bike on Prime when this occurs? It has been suggested that the fuel demand for a rejetted gs500 with pods is too much for the vacuum to keep up with on the high end (WOT). This was especially noted with the pre 01 bikes. Many folks go so far as to remove the vacuum petcock and replace with a pingel petcock or similar... though that's not really necessary, as switching to prime is truly just as effective of a solution if this is indeed what you are experiencing.
As yama pointed out, a lunchbox filter may be another 'tight fit' option for you for easier tuning, as many members have tried and true setups that work with known jets.. but this may just eliminate the variable of your intake, and you could still be left with the same problem at WOT if it is the vacuum starving the carbs in the first place. :dunno_black:
- Bboy
Quote from: BockinBboy on October 02, 2013, 05:41:25 AM
Have you tried running the bike on Prime when this occurs? It has been suggested that the fuel demand for a rejetted gs500 with pods is too much for the vacuum to keep up with on the high end (WOT). This was especially noted with the pre 01 bikes. Many folks go so far as to remove the vacuum petcock and replace with a pingel petcock or similar... though that's not really necessary, as switching to prime is truly just as effective of a solution if this is indeed what you are experiencing.
As yama pointed out, a lunchbox filter may be another 'tight fit' option for you for easier tuning, as many members have tried and true setups that work with known jets.. but this may just eliminate the variable of your intake, and you could still be left with the same problem at WOT if it is the vacuum starving the carbs in the first place. :dunno_black:
- Bboy
Good points ^^^^
Thanks Yama - I never really considered trying a K&N lunchbox as it just looked like two pod filters stuck together (well sort of...). But if it's worked for others...
Bboys comments on the petcock have got me thinking... I can't run it on prime as such (SV650 tank - no reserve, no prime, just the vacuum petcock) but I'm guessing I can take out the diagram and cap off the vacuum line for the same effect, plus it probably wouldn't hurt to clean it out anyway as the bike had been sitting.
Lets see how it goes...
Thanks,
Chris
may have to rejet my friend. BUT fwiw, the lunchbox, ive not had a problem with once a rejet was done. ( also when I cored my exhaust. requiring a rejet) but it was worth it. pod filters ive not liked tbh to me theyre as picky as a bad ex GF. everything has to be perfect. if one lil thing is SLIGHTLY off, it runs poorly.
Quote from: Sirhc on October 02, 2013, 08:17:10 PM
Thanks Yama - I never really considered trying a K&N lunchbox as it just looked like two pod filters stuck together (well sort of...). But if it's worked for others...
Bboys comments on the petcock have got me thinking... I can't run it on prime as such (SV650 tank - no reserve, no prime, just the vacuum petcock) but I'm guessing I can take out the diagram and cap off the vacuum line for the same effect, plus it probably wouldn't hurt to clean it out anyway as the bike had been sitting.
Lets see how it goes...
Thanks,
Chris
I had twin pods on the GS - FZR1000, GSXR750 (92-95 I think) etc etc fit and work great. Not any reason to go to RU 2970 IMHO.
SV tank ? pics please.
Cool.
Buddha.
Ok so it's not the petcock (tried direct feed with no improvement) and it's no a tank breather issue (ran it with open cap - no difference).
Took the carbs apart to check the diaphragms aren't worn/split/whatever, and can't see any issues. While I was in there I re-read the jetting info and decided to enrich the needle another clip which as far as I can tell is equivalent to 2x washers.
Bike seems to ride better, which is making me wonder if I was running super lean – couldn't see any reason why I would be lean at first, but then I realised that the pod filters are supposed to be oiled (Duh!) so now I'm thinking that I'm running waaayyy lean and that installing slide restrictors was just masking the problem. Does that sound likely?
Obviously I'm gonna get the filter oiled either was and I'll see if it helps...
Now I have another problem though – in going over the carbs again I noticed that the brass fitting/pipe that go's up inside the float assembly has a hairline crack running about 2/3rds down the side. Both carbs are the same and although tiny it's not a scratch - they are definitely cracked.
What is this part called? What effect would the crack have? and can it be replaced?
Here you go Buddha I've attached a pic of the bike so you can see the SV650 tank and plastics - Not sure if I like it or not - I think the rear end needs raising for it to look right...
[attachment deleted by admin]
How did u mount the tank and seat...any special tabs or cutting/welding needed....looove the seat
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Oh yea that is pretty cool.
Cool.
Buddha.
Hey Golly,
Couldn't say for certain - it was done by a previous owner, but by the looks of they have cut the original subframe off and welded on an sv650 one. I cant say for sure (never had a close look at an unmodified GS) but it looks like the subframe included the rear mount for the tank (it hinges up from the rear). The exhaust also looks to have been cut and re-welded at a slightly different angle to put it inline with the SV650 Exhaust mount.
BTW looks like my issue was a combination of cracked intake rubbers and un-oiled pod filters causing a super lean condition - still not running 100% but its 95% there. Feeling that new spark plugs, HT leads, and final jetting tweeks will sort the rest.
Still haven't figured out if the cracked carb part is an issue or not - gonna start a new thread to see if anyone knows :dunno_black:
TBH maybe that is what my problem was when i tried pods Eh?, (lack of oiled elements lol) if it were that simple id have been aggrivated. but this was in 2003 lol.