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Main Area => General GS500 Discussion => Topic started by: fox22182 on December 15, 2007, 01:19:10 PM

Title: need some engine help
Post by: fox22182 on December 15, 2007, 01:19:10 PM
So my bike a '95 GS500 with a V&H pipe I think possibly needs a rejet. After looking at the guide I can't tell if it's running too lean or rich. I bought the bike with the mods already done to it so I can't tell when/if the bike was ever rejetted. The airfilter is stock as far as I know and the bike has 28,xxx miles on it.

The biggest problem I have is that when I open it up some it staggers in acceleration unless I really open it up to get moving. It's like the throttle dips down then snaps back open and gets very frustrating. Some things I have noticed, the bike runs better warm but doesnt not fix the issue. I get bad gas mileage but I assume thats because I take lots of short trips and I'm having to leave the choke on for a while. The bike takes a while to warm up.

So basically I'm looking to reclaim my engine back, plz help!
Title: Re: need some engine help
Post by: ohgood on December 15, 2007, 02:46:04 PM
The rejetting matrix is a nice ballpark to work from. take a peek, but don't consider it gospel.

Help the folks that _know_ jets by describing when and how it coughs. For instance, does it stumble when you SNAP pin the throttle, or only when you slowly go to WOT ?

Poor fuel economy could be your style, jetting, air filter, or dragging a goldwing behind you ;)

THere are alot of factors. Give the gurus a while to respond, you'll find nice answers. :)
Title: Re: need some engine help
Post by: fox22182 on December 15, 2007, 04:08:54 PM
okay lets see. for example i was riding to dinner last night, about 78 degrees out, the engine was warmed up for about 3 min. I got on a big road and when to get it up to speed giving it I'd say 40%-50% throttle and the RPM's go from about 3k down to about 2k then I give it more throttle and it goes up to about 4k and continues to climb normally. I just really hate how it lags at first before snapping up, its like the powerband dips down before going back up.

as for the rejetting matrix, I've looked at it before but for a V&H system (not sure but I think its a full system) there are no rejet recommendations for a stock airfilter or a K&N dropin which would be another possibility or what I have as far as jets go now. I'd like to steer clear of rejetting for as long as possible being that I live in an apartment and maintenance is harder then if I had a garage. But I'll do what I have to do to fix this problem.
Title: Re: need some engine help
Post by: beRto on December 15, 2007, 04:16:36 PM
In my opinion, you should get the bike working with the stock jetting before you start messing with that and introducing new variables. The stock jetting may not be perfect, but it shouldn't cause bogging or similar problems. I suspect you have some other issue.

*edit* sorry, didn't realize you'd replaced the exhaust... rejet may indeed be in order; my bad  :oops: :cry:

p.s. nice bike! Mine's a '95 too.  :)
Title: Re: need some engine help
Post by: kml.krk on December 15, 2007, 07:23:05 PM
I think you're running lean IF the bike has not been rejetted. With V&H exhaust, which is open exhaust, you have too much air flowing thru the carbs and too little fuel. US stock bikes are running a bit lean from factory (at least the naked version), so by installing the V&H exhaust without rejetting the PO made your bike even leaner than it was.

cheers
KaMeL
Title: Re: need some engine help
Post by: fox22182 on December 15, 2007, 08:33:10 PM
that was my suspicion. Damn lol, I'm scarred to have to rejet. Looks overly complicated. I have the tools and could probably manage but I'd be afraid I couldn't get everything put back together right.

If I have to rejet and I put the K&N drop in, any idea what I should rejet to? anything else I should check while I have the carbs out?
Title: Re: need some engine help
Post by: yamahonkawazuki on December 16, 2007, 01:35:05 AM
its as simple as sex  ;) basically involves some screwing :laugh:
Title: Re: need some engine help
Post by: fox22182 on December 16, 2007, 10:01:55 PM
any idea what I should rejet to? I'm in the dark here.
Title: Re: need some engine help
Post by: kml.krk on December 17, 2007, 02:54:29 PM
try this post:  http://gstwins.com/gsboard/index.php?topic=39124.0;topicseen

should help
Title: Re: need some engine help
Post by: nastynate6695 on December 17, 2007, 06:17:31 PM
try to go with the lunchbox filter instead of the drop in.  littlle bit better i believe 
Title: Re: need some engine help
Post by: fox22182 on December 18, 2007, 05:48:50 PM
kml your link was to this topic.... not sure what you meant to link.....


doesn't the lunchbox filter make your bike louder? the V&H makes it loud enough, I live in an apt complex and I know my neighbors are already hesitant about the noise I make when I leave for work at 7 so I really don't want to make it louder.
Title: Re: need some engine help
Post by: spc on December 18, 2007, 06:22:19 PM
Adding a lunchbox filter is not going to make your bike notably louder from any distance.
Hit the Wiki, check the jet matrix and use that as a starting point.
Title: Re: need some engine help
Post by: nastynate6695 on December 18, 2007, 06:24:20 PM
it shouldnt be louder..IT makes it easier for the engine to suck the air in.  The lunch box bolts right onto the carbs where as the drop in welll.....drops into place..  The airbox and the airfilter hole are right underneath the seat whereas the the lunchbox pulls it more in from the sides..But who knows i never tried to test the noise difference..besides  if the neighbors complain just tell them to wait untill you get your harley ....then see what the definition of loud is..
Title: Re: need some engine help
Post by: kml.krk on December 18, 2007, 07:01:33 PM
Quote from: fox22182 on December 18, 2007, 05:48:50 PM
kml your link was to this topic.... not sure what you meant to link.....


doesn't the lunchbox filter make your bike louder? the V&H makes it loud enough, I live in an apt complex and I know my neighbors are already hesitant about the noise I make when I leave for work at 7 so I really don't want to make it louder.
sorry bout that! I meant this topic: http://gstwins.com/gsboard/index.php?topic=35237

I think that lunchbox makes your bike louder but not "outside"... people you're passing by will not notice the difference but you will. The intake noise is louder but performance is greatly improved, so lunchbox is worth considering. And it's cheaper than drop in.
cheers
KaMeL