Getting the bike tuned at cyclewerx?

[Erch]

First off, sorry, this isn't a bike meetup thread. I'd normally ask general questions about bike maintenance at gsresources and questions about local shops at GTAM. But this is something that kinda falls between:


I hadn't bothered to do a carb sync on my gs750 since the whole ignition system was out taking a piss. But now that I've gone electronic and got a new pair of coils the thing's actually running happy enough to bother getting right.

Now I've got the timing set, bigger main and pilots and the needle up one notch (mostly because the original notches are so worn I was afraid the e-clips would fall out). I've really just got to get the idle mix, air mix and synced.



So here's the situation: I was on my way home the other day and decided to drop by and ask Tom what he'd charge for a carp sync. He said he'd round up to an hour so $75 and he'd set idle, air and sync. Just for fun though he came out to the bike and listened to it idle, which it was pretty inconsistent at (I had set the throttle to about 1500 to make sure it wouldn't stall out at lights) and he starts fiddling with the air mix, cranks them pretty far out and doesn't touch the fuel mix. Long story short he got it to idle quite nicely in the 900-1200 range.

Problem is, now the bike's taking more choke than I can give it and about 1/4 throttle to start, the throttle response is down and it feels pretty thirsty at the top end. This got me a little worried.


TL;DR: Do I...

-Give Tom at cyclewerx $75 and trust him to do a good job.
-Take the $75 and build my own sync contraption, pretend I know what I'm doing and ballpark the thing until I'm happy and hope I get it right?
-Take it to x/y/z who'll do it cheaper/better than cyclewerx


I'm not looking to take this bike to the dyno, I just want to make sure it's not going to burn out or foul up on me. Considering I'm going to change the pipes at some point too I don't really want to waste too much effort on it.

 

[bobjohnson]

Ill just say, i dont like cyclewerx. Had nothing but bad experiences there. People seem to love it though, and i really do wish i had better experiences cus its like 2 minutes from my house, i could push my bike there if i had to.

I vote for sync the carbs yourself though. I put it off myself for a long time, but i wish i hadnt. Building the tool is super easy (at least the "tubing on stick" method, never done the glass jar style), it takes like 35 minutes and 30 of those minutes are waiting for the air bubbles to come out and whatever liquid you choose to leak down the tubes for an accurate read. Grab a set of adaptors if you need them, motion pro makes them, and they slide into 1/8th (or 1/4, i forget off hand) tube nicely, parker bros can order them for 25 bucks, TO Cycle has them in stock for a bit more. Read a couple tutorials on how to sync carbs and go to town.

Just make sure to use 2 stroke oil and give yourself nice, long lengths of tube. I used the 25 foot roll you can get at home depot, meant for chemicals and 2 stroke oil didnt eat through it. I kinda wish id used 50 foot though just so i could get the tool hung up a bit farther away from the bike. I like using the 2 stroke oil because if you DO screw up, or you get distracted and for some reason the bike revs up, 2 stroke oil isnt going to damage your engine like water or something else will. Worst case scenario you foul a couple plugs.

As for setting the idle, its also pretty easy. Put all your adjustments to stock (itll be in the manual) and see where the bikes at, idle wise. Listen to the cylinders and starting with the first, SLOWLY turn the airmix screws (i do about 1/8th turn, some people say 1/4 works but i dont think thats a fine enough adjustment) to get the highest, smoothest possible idle. Give it 2 or 3 seconds to take effect. Youll really have to listen to the cylinders here but you'll know when you hit the sweet spot, itll sound perfect. If you cant tell at first, turn them a bit in and listen to the change, and then a bit out and listen. One way will definately sound better than the other, and if you turn past the sweet spot itll sound bad again, so you'll know when youve hit it. Repeat with the rest of the cylinders. Then, check the idle. Adjust the idle screw (if theres more than one, adjust both the exact same amount, again, in 1/8th or smaller turns) until you hit the spec idle. With slide carbs you have to twist the throttle a bit between adjustments for the slides to settle back down on the stop screw. If the bikes running badly again after adjusting the idle, dont worry, you didnt screw up, you just have to go back to the airmix screws and start over from the beginning. Sometimes it can take 5 or more tries until you get it perfect. It sounds complicated but really you can perfect this and get it down to like a 5-15 minute operation.

So set the idle first, and then do the sync. As to how to do the sync, itll depend on if you have CV carbs or slide carbs, so look up the applicable tutorial (i only know how to do slide carbs, never had CV carbs until my most recent bike). Just remember, all this stuff is only for fuel delivery at idle. If you want to know how your bikes running at part -> WOT, you'll need to do plug chops or get it on a dyno with an EGA.

Good luck!

 

[Tim]

I've had decent experiences at Cyclewerx, but haven't had tuning done there.

There's nothing Tom could have done to change the behaviour at the top end of the throttle. The air mix screws only play a role in the bottom 1/4 throttle or so.

If you want to give it a shot yourself, I have a set of the EMGO carb sync gauges you can borrow. I honestly don't know how good they are - never really used them.

I bench sync my carbs at the side of the road if things aren't running right With my 2 Mikuni VM carbs it takes 5 minutes. I've done the SOHC4 thing in the past - that's why I've sold all my 4 cylinder bikes and only own twins and thumpers now

Let me know if you want to borrow the gauges. Worth a try on your own before spending money. If Tom guarantees the job and will fiddle with it till it runs well, then $75 isn't a bad deal.