gs450 - still not running right

[KiwiAlfa156]

The orientation convention is LH RH as if you are sitting on the bike. The other naming convention is Cylinder number 1 is the left most one, sitting on the bike facing forward. In the case of a twin, the RH cylinder is number 2.

So to be clear.

LH (cylinder 1) plug going brown, header is ~350°F
RH (cylinder 2) plug no colour, header is ~250°F

From that I'd say your LH is your good one, you RH is way too cold. It's just above boiling point of water.



I'm picking a clogged pilot jet in the RH carb (or pilot outlet/screw) possibly by-pass orifices.

[bren]

Yes, i'm using the same left = cyl 1 terminology.

now, just to be clear, before I took the carbs apart and dipped them, the left cylinder was cold, and the right one was hot. initially, the cold cylinder had the darker plug and the hot one had no color. i switched some part when i put the carbs back together, and now, the right cylinder is cold. I'm in the process of elimination to find out what part is making the difference. I'm also converging on the pilot jet.

I'm not sure if the cold cylinder is too rich, or if the hot cylinder is too lean. On that video, The bike was still slightly warm, but not like "warm" warm, just above room temperature type of warm - just warm enough to start without choke. and it only ran for about a minute or two at idle, so it wouldn't have time to get fully hot. My feeling is that the hot cylinder is getting too hot too fast, but I am really not sure. The ambient temp today is right around 70F.

[KiwiAlfa156]

Did you remove the jets when you cleaned or just dipped the carbs with the jets in situ?

Exhaust gas is about 350°F so that tallies with you hot pipe.

[bren]

i completely disassembled everything, with the exception of one main jet which i didn't want to disturb because it's a little stripped. I didn't take apart the slides either. apart from that, every jet came out. that list i wrote earlier in the thread is every component that could have gotten switched over upon reassembly.

edit: i'll add that the last time i let it warm up for a little longer, the cold header got up to 350 and the hot one got up to 450 and beyond. i only cut it during the video because it ran away when i flicked the throttle

[Rob S.]

...it ran away when i flicked the throttle

Doesn't that usually indicate an intake air leak?

[bren]

Doesn't that usually indicate an intake air leak?

yes, that's my understanding, or it could indicate a severe imbalance between carbs. but also a leak would lead to a lean condition. the fact that the lean condition switched cylinders leads me to want to rule out any air leaks

[dgates1]

Well first mistake I see from the video is the Morgan Carbtune is designed to work when it is hanging straight. You have it hanging straight but it is upside down. Should be hanging from the top side where the hoses connect. That could skew your balance reading.

Second thought after watching is, do the throttle plates stick at all, or perhaps your throttle cable is sticking?

[oldGSfan]

I find the water-based Berryman's dip less effective than the original. Now I dunk the carb and parts in the Berryman's basket and put the bucket in my large ultrasonic for 10 minutes. They come out amazing. I have had nothing but carb rebuilding success since I started doing this, and a lot of troubles previously.

Of course, an ultrasonic that's big enough to fit the carb would work, it's just more convenient with the extra large one I got for $80 a few years back. I recently used it to unstick a slide on a Keihin that was gunked up with years-old varnish. It took 20 mins, and fell right out.

[bren]

Well first mistake I see from the video is the Morgan Carbtune is designed to work when it is hanging straight. You have it hanging straight but it is upside down. Should be hanging from the top side where the hoses connect. That could skew your balance reading.

Second thought after watching is, do the throttle plates stick at all, or perhaps your throttle cable is sticking?

the booklet it comes with says, if your bike doesn't pull enough vacuum to move the slides with it right side up, you can use it upside down to get the sync right, and just ignore the quantitative reading, to get it in sync without taking measurements. mine wasn't strong enough to lift the slides so i flipped it.

there's actually a hanger on both ends for that zip tie the carbtune comes with, for this purpose.

no, there's nothing sticking. it's perfectly snappy.

[bren]

I find the water-based Berryman's dip less effective than the original. Now I dunk the carb and parts in the Berryman's basket and put the bucket in my large ultrasonic for 10 minutes. They come out amazing. I have had nothing but carb rebuilding success since I started doing this, and a lot of troubles previously.

Of course, an ultrasonic that's big enough to fit the carb would work, it's just more convenient with the extra large one I got for $80 a few years back. I recently used it to unstick a slide on a Keihin that was gunked up with years-old varnish. It took 20 mins, and fell right out.

i've heard people say this online. the EPA stuff is really frustrating. my carbs also have non adjustable needles, and jetting that's right on the brink of being too lean. thanks to EPA "eMiSsIoNs StAnDaRdS"

i'm not sure that i can justify buying and ultrasonic cleaner unless I make a hobby of resurrecting a bunch of old bikes. although 90 bucks at Hobo Freight aint too bad. I might think about it. I'm just getting tired of buying a bunch of stuff at this point!

i've even read about people using berryman's sauce inside of an ultrasonic ... that sounds like it would really do the trick!

[oldGSfan]

i've heard people say this online. the EPA stuff is really frustrating. my carbs also have non adjustable needles, and jetting that's right on the brink of being too lean. thanks to EPA "eMiSsIoNs StAnDaRdS"

i'm not sure that i can justify buying and ultrasonic cleaner unless I make a hobby of resurrecting a bunch of old bikes. although 90 bucks at Hobo Freight aint too bad. I might think about it. I'm just getting tired of buying a bunch of stuff at this point!

i've even read about people using berryman's sauce inside of an ultrasonic ... that sounds like it would really do the trick!

Yes, you can put the sauce directly in the ultrasonic, I just like the simplicity of putting the bucket in the water. The ultrasonic 'cheapo' ones you find from China appear to all be the same design, based on the controls, and there are huge price variations. I found mine for $75 and saw others were > $200 that were exactly the same. I barely missed getting a medical grade one for cheap, dang. But my cheap one has worked well for a few years.

Given that I fix most everything myself and have amassed a huge array of tools that paid for themselves many times over - vs. being ripped off by some 'pro', I occasionally lash out and splurge on something that will make my life easier.

I'm still scratching my head over your issues. I had a GS1100E behaving strangely/badly depending on load and temperature. It was the aftermarket no-name coils, putting stock ones on fixed the issue. But having the problem move to the other cylinder does point to carbs.

[KiwiAlfa156]

Originally posted by bren View Post ...it ran away when i flicked the throttle

Doesn't that usually indicate an intake air leak?

Can do, it's indicative of a lean idle mixture, either due to extra air (leak) or not enough fuel (clogged jet or passages).