Carb sync gauges to avoid??

[Guest]

Ok, so rather than ask what gauge set is best to sync my carbs with, I'm gonna ask "Is there a set of gauges I should all out hands down avoid?" Not looking to spend a Benji for a tool I might only use twice a decade, but I'd like quality with predictible results-no aerospace accuracy needed. Any proper fitments of the accessories of course! All suggestions greatly appreciated. Thanks in advance.

 

[cowboyup3371]

If you are thinking you'll only use it twice a decade then I am assuming you don't intend to ride much at all? You'll need to use it every time you do a valve adjustment which is every 4000 miles. That could be at least once a year if you do a lot of riding or longer if not. You may also want to do it to troubleshoot issues like what I was going through.

Save yourself the future heartaches and buy a Morgan Carbtune - with the exchange rate today, it's about $100. It's very simple to use and comes with its own case. Get the adjustment tool too you'll be set.

 

[Redman]

I got the Motion Pro.
And after a couple years or more the fluid all dried up.

 

[bwringer]

Yep, the Morgan Carbtune is the bee's knees. The rest aren't worth bothering with.

Some folks have tried making their own. In every case I'm aware of it's mostly a waste of time and a great way to slurp ATF or water into your engine. The money you'll spend on tubing would be better put toward a Carbtune, and the time you'll waste would be better spent earning a few bucks to buy a Carbtune.

And those gawdawful cheap dial gauges you'll find on fleaBay... no. Just no. COMPLETE waste of money, time, and space. Put the $50 into a jar and save up your pennies until you can get a Morgan.

If you're really caught that short (it's a fact of life: motorcycles cost money) perhaps you can join forces with a couple of other local riders. Pretty much every two, three, or four cylinder motorcycle needs synchronizing, so most of your pals with a two-wheeler will have the same needs and might be willing to chip in.

 

[Steve]

I have a few here to choose from:
Mercury 'sticks' with 6 columns.
Motion Pro with the blue fluid.
Suzuki OEM gauge with the balls.
Morgan Carbtune II.

I started with the mercury sticks 40 years ago. I got the 6-column version because I had a KZ1300. Nice, easy to use, accurate, but uses a rather toxic element, which requires EXTREME care during use.

I got the Motion Pro unit about 15 years ago. It was used and empty. I got replacement fluid, found that two of the columns leaked. Attempted a repair, managed to get one of them sealed up, but it required a second purchase of replacement fluid to find out.

I got the Suzuki gauge about 8 or 10 years ago from a member that was selling his. I used it to determine how much the "half a ball difference" was, and really haven't used it since then.

I got the Morgan Carbtune about 5 years ago. Very easy to use, accurate when used correctly, reasonably rugged, but it does require a bit of common sense in its care.

I have used, but do not own (and probably never will), a set of dial gauges. Just way too awkward to use, especially since you have to verify calibration every time you use them.

I have multiple bikes here, so I use the gauges a bit more than most. I also work on bikes for others, so they are used even more. While in my shop, I still prefer the mercury sticks, but if I ever have to travel to work on a bike, it's the Carbtune in my tool box.

Save your pennies, skip a Starbucks or two, you will soon have enough to get your own Carbtune.

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[Guest]

Thank you all for setting me straight Seeing as I only have the one bike the gauges will get little demand. Currently the Carbtune is for around $139 shipped. Ouch!! And I dispise Starbucks
for creating an addicted, self-loathing society that must have indulgence at every 1/4 mile. Home & Family come first; Carbtune and a worthy ride will just have to wait. Besides, Summer is officially over *sigh*.

Thanks again

 

[Steve]

Currently the Carbtune is for around $139 shipped. Ouch!!

I don't know where you are shopping, but I hope they are at least kissing you while they are raping you.

Please share the source that you almost considered.

Order a Carbtune DIRECT. Click HERE, you will see that it is 73 GBP for a Carbtune and carrying case. Click the link on that page for currency conversion, you will see that today, it is $87.5875 USD.

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[fbody_mike]

I just ordered a CarbTune direct. I will call it a Brexit sale, as it was $88 shipped! Can't beat that price. I need to replace my MotionPro mercury sticks as it doesn't have enough mercury to sync my GSF1200S, I have to keep shutting the motor and restarting to get the air out of the tubes. Hopefully the CarbTune is as good as everyone says it is.

 

[Guest]

Dang, Steve-That IS a great price!! I merely pulled up a google search & about three resources popped up all at around $138...most likely amazon come ons. With that I snuffed the idea, thinking the exchange rate was what suffered.. Didn't realize you could order direct! This I think I could swing. Thank You, Steve!! My colon thanks you too ��

 

[fbody_mike]

When you order yours see if they include this special instruction with the emailed invoice.

"DO NOT SUCK CARBTUNE WITH YOUR MOUTH"

I did not have any plans to do this.....then I started to wonder if Morgan put that because I am in California.

 

[Tom R]

I just used my carbtune for the first time last night... worked great at determining that the bench sync got things close enough so I didn't have to do anything but put everything back together - lol - maybe a 1/4" difference from the highest to lowest.
Would have saved me a lot of trouble if they included those instructions with mine.

 

[adalah]

never experienced it. but this is a very interesting discussion to follow

 

[TowPilot]

I like my carbtune but don't like the little plastic connectors. Buy the motion pro brass connectors and then you have a good setup. They make getting to the inside cylinders easy.

 

[Guest]

Well, I took the plunge & ordered one. The exchange ticked up slightly since Steve posted, but still got it out the door at under $90. Now learning that the adapters are nylon/plastic? That's kinda bummersville (all their pics show brass-bit of a mis-lead). They now include the toolpouch thou, so . . . I'll be easy on the adapters I guess. On a side note:

Does anyone know the thread pitch of the vacuum plug screws, or better yet, are they the same as that of the float bowl drain plugs? It'd be nice to dual-purpose the Carbtune adapters for float height checks, and if the threads match that'll pursuede me into buying Z1/Motion Pro brass adapters for sure.

 

[bwringer]

I'm not 100% sure this applies on your bike's VM carbs, but:

On CV carbs these are different diameters; the vacuum plugs are 5mm, normal .80mm pitch. (Again, please verify this on your actual bike. I seem to recall VMs use the same thread, but it's been a while...)

The carb drain plugs are 6mm, but an oddball fine pitch; I can't remember offhand the thread pitch used on these, but I suppose someone will be along soon who does know.


The plastic adapters work fine, but it can be hard to grab hold of them. You can add a short piece of tubing to help reach and thread them in. The brass ones from Motion Pro are longer and somewhat easier to grab, so that's what I typically use.

They're pretty cheap, less than $9 for a set.
https://www.amazon.com/Motion-Pro-08-0013-Carburetor-Adapter/dp/B000OO4PVM

MP also sells brass adapters that you could leave in place; the trouble here is that the crappy rubber caps they supply quickly deteriorate and fall off.

I don't know of a source for rubber caps that can actually last, but you could just add higher-quality tubing (you'd need to use something that can tolerate fuel and heat) and cap the tubing.

 

[Steve]

On CV carbs these are different diameters; the vacuum plugs are 5mm, normal .80mm pitch.

It's the same on all GSes, regardless of carb type.

The carb drain plugs are 6mm, but an oddball fine pitch; I can't remember offhand the thread pitch used on these, but I suppose someone will be along soon who does know.

The bowl drains are M6 x 0.8. That is the standard "fine pitch" for M6. I need to order one of those taps. I have an M6 x 0.5 tap for chasing threads on the pilot screw, but it does not work for the drain screws.

The plastic adapters work fine, but it can be hard to grab hold of them. You can add a short piece of tubing to help reach and thread them in. The brass ones from Motion Pro are longer and somewhat easier to grab, so that's what I typically use.

I have heard that the reason the Carbtune uses the nylon adapters is to minimze the possibility of cross-threading the ports. I got my Carbtune used, and it came without adapters. Fortunately, I have some brass adapters for my mercury sticks, so there ws no problem.

MP also sells brass adapters that you could leave in place; the trouble here is that the crappy rubber caps they supply quickly deteriorate and fall off.

I don't know if they are the same thing, but I got some of those 'permanent' adapters from Z1. I installed them on my bike, then went for a ride. When I stopped for a break, I noticed that it was running a bit rough. I looked at the engine and saw that one of the caps was missing. I had some electrical tape in the trunk, so I covered the port and went to an auto parts store to get a vacuum port cap assortment. The next morning, I started the bike. While it was warming up, it did its usual hiccup back through the carb and I watched another cap disappear. I went through the selection of caps to install the absolutely TIGHTEST fitting ones. They got spit off, too. If your bike absolutely NEVER spits back during warm-up, the permanent adapters might work, but I removed them from my bike about a day after I installed them.

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[Guest]

"The bowl drains are M6 x 0.8. That is the standard "fine pitch" for M6."

I was assuming the drains were M6x0.75 due to another thread related to the plugs...need to confirm as I try sourcing some nipples. Nonetheless, if the adapters don't work there then so be it. Thanks again guys for everything!

 

[Steve]

I’ll check the thread pitch again. :-k

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[Guest]

I based my thoughts on post no.3 of this thread:

https://www.thegsresources.com/_forum/showthread.php?222912-Float-bowl-drain-and-fuel-height-level-adapter

 

[Steve]

OK, I have checked a drain plug. I did not get a picture, but my 0.75 gauge did not fit.

I'm having a bit of difficulty trying to match up a 0.8 gauge because Harbor Freight strikes again.

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