Just got GS back from Shop and now weirdness is happening...

[00sanchez]

Ok, I just got my 98 gs500e back from the shop (after three weeks). They rebuilt the front forks, rebuilt and synched the carbs, rejetted, redid the seals on my tach (still doesn't work properly) and installed a K&N Lunchbox. I've read this forum for a while, and something sounded odd when I left the shop with the bike. He had said that he upped the size of the jets as much as possible; however, when I looked at the invoice after getting home, the sizes of the jets were 32.5 pilots and 125 mains. I've read the rejet wiki and for what I have, it should be closer to 40 pilot and at least a 140 main with a washer. I'm almost positive there are no washers since he had said there was an extra one on the needle (it was missing the washer on the other needle when I opened the carbs previously).

What my bike currently has done to it performance-wise is the lunchbox filter and a slipon HD sportster exhaust (which I can only speculate). I can post a few pics later.

Anyway, what is happening now is the revs are very slow to come back down to idle after reving it. Also, before the bike is completely warmed up (at least today), it sounds like there is backfiring in the carbs for a while which went away after about 5 minutes of warming up the engine. In first gear only, the bike will give some hesitation on takeoff and will not give much power after about 3-4k rpm. Second gear has great pickup. Lastly, I went for a good 100 mile ride yesterday and late in the trip, it would backfire once after turning the engine off.

So, any ideas I should think of before taking this thing back to the shop and not seeing it until mid summer?

[Paulcet]

I see two options: 
1.  Fix it yourself, which is easier than you think. 

2.  Take it back and argue with the shop.  And it will be an argument.  Unless he can show you the A/F ratio throughout the rev range.

[00sanchez]

See, I want to fix it myself, but last time I removed the carbs, I ended up making things worse. If it is as simple as rejetting up to 40/140 or so, I can do that with no problems; however, if there's a vacuum leak causing the hanging idle or some oddness like that, I'm probably not the guy to go to

From what I understand, hanging revs are caused by lean mixtures or vacuum leaks, but backfires out the exhaust are caused by unburnt fuel, which would mean a rich mixture? Also what causes backfires in the carbs on a cold engine?

And, yeah, I really don't want to have an argument with somebody that, in theory, knows a lot more about motorcycles than I do. I mean, the pilot jet they put in is 32.5 but the stock jet is 37.5? I would imagine that putting the k&n would allow a lot more airflow, which would require more fuel? But, like I said, I have never really worked on a motorcycle successfully, so I'm a bit worried to go back into it.

But, you guys are very specialized in your bike knowledge here, so I will definitely take your word over an indy shop. If you say put in bigger jets, I'll do it. I don't think I can f%$k up that much. If I did do this, or any other suggestions, would I need to resync the carbs?

[dougdoberman]

Yeah, if those numbers are right they've gone DOWN in jet size, which is completely the opposite of where they should have gone. 

I just did the jets in mine after adding the K&N to the stock exhaust.  40 / 140 felt about as close to perfect as I was gonna get without hooking up an A/F mixture meter.  I expect to go up to around 150 on the main when I add the full exhaust later this week.

Your hanging revs could be a number of things.  Find the main thread discussing it and work from there.

Personally, I'd be finding a new shop.  If they sent it out the door in the condition it's in, they shouldn't get any more of your money.  If they're the only ones close, then accept the fact that you've gotta take it further, or get a shop manual and start doing the work yourself.

[Funderb]

he sizes of the jets were 32.5 pilots and 125 mains.

With the lunch box, you should be much larger. you are dangerously lean on the pilot with that size jet, and annoyingly lean on the main.

[craigs449]

The backfiring from the exhaust is most likely a leak somewhere in the exhaust.....Hot exhaust gases mix with cold outside air prematurely and causes backfiring.  I would suspect this since you mentioned some modded sportster can.............Check the header bolts and junction where the can meets the midpipe.

[00sanchez]

Thanks a lot for the advice, guys. I'm going to call the guys back and see if they'll rejet and resync for a discounted price or for free since they messed it up. If not, I'll be going at it alone and will probably need some help

[00sanchez]

Ok, just called the shop. He said he put in what they took out jet wise, which means they didn't even think to compensate for the new filter (going from a drop-in k&n to a lunchbox). I'm completely baffled. Well, if it weren't for you guys and this site, I could have really screwed up my engine driving it around like this.

New questions. I've already driven about 130 miles since getting it back. What kind of damage could I have done, how do I look for it, and would it be safe to drive this up to the shop (about 30 miles away) or should I get a friend to loan me his truck to haul it up there?

Again, thanks a lot, guys.

[Big Rich]

Um.......buy the jets and put them in yourself? Even if you just put in the mains, you'll be doing a favor to your motor.

Where are you located man?

[craigs449]

I don't think you will cause any problems with the 30 mile trip as long as it's not 110 degrees outside!  What idiots to open up the airbox and not up the jetting....this is why I trust no-one (except for a few motor and suspension gurus) to touch my bikes......

[Big Rich]

Forgot to add - you could also put the stock airbox and filter back on as well until your problem is solved.

[00sanchez]

I'm in Northern Indiana near Ft Wayne. And the reason I don't do it myself is just in case it isn't the problem and they find a leak or something. Mostly it's because they have certifications and I don't. Unfortunately, I'm one of those people with no confidence to do something myself unless I can't make it worse. Somehow, some way, I always seems to break things that are mechanical even when following instructions. I mean, I'm no idiot, but working with my hands is my weak point.

If this second round goes poorly with the mechanics, or they charge me for their own mistakes. I'm going to push through and cross my fingers by doing things myself. I've just been without my bike for so long, I'm getting depressed.

If I had somebody looking over my shoulder, I'd love to work on my own bike

[craigs449]

here's your certificate.....Now get to fixing your own damn bike!

[Big Rich]

We aren't trying to bust your chops man. Really. It's just that it's kinda obvious that the shop made a mistake doing something that many people think is an easy job. With the proper tools, a little patience, and the tons of info available here, swapping out some jets is something you can do yourself.

[adidasguy]

..... Unfortunately, I'm one of those people with no confidence to do something myself unless I can't make it worse. Somehow, some way, I always seems to break things that are mechanical even when following instructions. I mean, I'm no idiot, but working with my hands is my weak point.....

Been there. First muffler change and rear set install I had help.
Now I just jump right in after reading all the advice and mistakes others have made.
I never thought I could build up a bike from a bare frame. Sure, I did have motors in need of work then got one that was running and used it. So I didn't have to repair the motor. I did learn to take it out and put it in the other frame. I learned how to run the wiring harness (and have had to re-run some wires). I jumped in and tried.
I rejetted a carb! I did all kinds of things when Trey was acting up.
The key is just do it. Have all the literature: factory service manual, Haynes and Clymer manuals if you can. Each book presents information differently. Have a parts list (you can get printed parts book) so you know what goes where. Take pictures as you disassemble  things. I photographed everything on the parts bike as I stripped it. Now I will compare the pictures tonight to the wiring on Phenix to see if everything is where it should be.

So just get in there and do it.

Soon I will attempt a cylinder honing and new pistons on one of my spare engines. Kind of afraid - but you gotta learn sometime.

If you can, buy a second bike. You have something to ride while you take one apart. You can look at the other bike to see how things go together. (I do that a lot!)

Forks: couple hours at most.
Carbs: a few hours the first time. Buy a spare set for $75 so you have a set to tinker with.
Just changing pilot jets: a few minutes. More time spent is getting the carbs out and back in. I just did 40 pilots on Trey - nothing more. What an improvement!

Spend money on tools and spare parts rather than on shop labor. You'll be way ahead that way. I only go to the shop now for tires. Free install and balancing if you buy the tires there and usually 25% off on tires.

I am amazed that I was able to remove and install an engine by myself. Reading the posts here gave me the background knowledge. I'm still amazed I was able to put it in in 17 minutes and still take pictures and have beer while doing it.

You can do it. You have the certificate to prove it!

PS: And do one thing at a time. I learned that in bowling. If you have a problem - don't change the ball, the approach, the release and your mark all at once. You have no idea when helped or made your bowling worse. With your bike: you changed are filter, jets, exhaust and probably other things all at the same time and now it doesn't run well. Which thing caused the problem? Hard to tell. Change one thing at a time. If it made it worse, you know what went wrong.

[00sanchez]

You guys are the best. I'm going to do it. Ordering the 40 pilot and 140 mains. I'll give some updates when everything blows up

[craigs449]

You guys are the best. I'm going to do it. Ordering the 40 pilot and 140 mains. I'll give some updates when everything blows up

Atta boy    Hang your certificate on your garage wall with pride 

[Funderb]

if you pm me your email address, the suzuki factory service manual could possibly appear in your inbox.

[average]

^ I'll take you up on that! 

[Funderb]

the link is out to you two kids, enjoy. And enjoy my old webpage, its some quality stuff.