Running rich, I need some advice, please

[gs450sjip]

Yes and no. I agree it indicates a lean condition. What procedure was used to set the idle mixture screws? The highest rpm method listed on BikeCliff's site is for VM carbs, not CV carbs.

KOOLAID KID,

I just backed them out 2-turns after seating them lightly. They were not on the bike yet. There is no point messing with them until I get the air leak corrected. I suspect the right carb clamp is stripped, I could not tighten it nearly as tight as the others. I'll check after work today. GS450SJIP

[koolaid_kid]

I asked because I had the same issue on my GPz. I first checked for air leaks, had none, then discovered that the Fast Idle method was at fault. I figured out how to set them correctly and now they are perfect. I wrote a procedure up on how to set them correctly if you are interested.

[gs450sjip]

I asked because I had the same issue on my GPz. I first checked for air leaks, had none, then discovered that the Fast Idle method was at fault. I figured out how to set them correctly and now they are perfect. I wrote a procedure up on how to set them correctly if you are interested.

KOOLAID KID,

I am all ears !! Yes, I need some guidance here, all my other bikes are BSA's, the Amal carbs are quite simple compared to these Mikuni CV types.

my email is: jipjap@netzero.com

thanks, gs450sjip

[koolaid_kid]

Here is the thread
I asked BassCliff to post it on his site, but he has not gotten around to it yet.

Amals, geez. I remember a friend of mine tickling them on his Bonneville 650 back in 1969. Hehe.

[gs450sjip]

hjfisk,

Yes, I agree, it is a possibility. I will check for leaks, It did not rev as before, seemed sluggish without power. I did hear a odd , very slight, popping or spitting sound on occasion. It was never there before, so I think I'll loosen all clamps, try to reposition the carbs, then retighten them.
Thanks, GS450SJIP

Gents,

I discovered an air leak on the right carb boot right at the carb to boot joint. Spraying carb cleaner changed engine speed noticeably. I replaced a split one months ago, now this one is not sealing. So, I just placed an order for a new one. The saga continues, but at least it's starting to make sense. gs450sjip stay tuned......

[hjfisk]

Gents,

I discovered an air leak on the right carb boot right at the carb to boot joint. Spraying carb cleaner changed engine speed noticeably. I replaced a split one months ago, now this one is not sealing. So, I just placed an order for a new one. The saga continues, but at least it's starting to make sense. gs450sjip stay tuned......

That will cause a hanging idle.

[gs450sjip]

That will cause a hanging idle.

Latest update Gents,

I installed a new carb pipe and o-ring on the offending side. Surprisingly, there was no change, still sucks air in on the carb to boot joint on the outside edge of the carb. After examining the tight fit of these pieces, I wonder. Could it be leaking under the aluminum cap on the end of the throttle shaft? I know there is a seal of sorts in there, this is on the carb body I replaced, so I don't know the history of it. Still a hanging idle. Next test will be to put a hose over the casting on the throttle shaft, after removing the cap. Shoot carb cleaner in the hose to see if the leak is in the shaft seal or not. Personally, I don't see how it can leak at the boot to carb neck joint. It is soft, pliable, and tight fitting.

Advice appreciated, gs450sjip

[gs450sjip]

That will cause a hanging idle.

Gents,
While I'm waiting for the throttle shaft seals to arrive, I have a related question:
Are there supposed to be internal seals on the bottom of the choke plunger? I ask because I don't recall seeing anything there, some photos show a small black area surrounding the protruding shaft on the bottom. Is this the cause of the richness I experience?

Thanks, gs450sjip

[pete]

If you have lots of patience, go through my engine rebuild photos on Photobucket and see how mine compare with yours.

http://s594.photobucket.com/albums/t...ine%20Rebuild/

I don't know what's going on with Photobucket but lately I just keep getting connection errors and timeouts and it's ridiculously painful to even view photos I've got there let alone upload new stuff.

They also appear to have re-ordered all my photos so you're just going to have to sift through... don't have time to go and find the individual ones for you I'm sorry.

[gs450sjip]

If you have lots of patience, go through my engine rebuild photos on Photobucket and see how mine compare with yours.

http://s594.photobucket.com/albums/tt26/starpoint73/GS450/Engine%20Rebuild/

I don't know what's going on with Photobucket but lately I just keep getting connection errors and timeouts and it's ridiculously painful to even view photos I've got there let alone upload new stuff.

They also appear to have re-ordered all my photos so you're just going to have to sift through... don't have time to go and find the individual ones for you I'm sorry.

Pete,
I have reviewed your build earlier. I studied it well, thanks. I checked the chokes , they are sealing well. After replacing the throttle shaft seals, I am out of ideas. I hope this does it. Stay tuned....gs450sjip

[pete]

Good stuff, my fingers are crossed for you!

[gs450sjip]

Good stuff, my fingers are crossed for you!

Pete and all,

Here is the latest scenario:
Replaced the throttle shaft seals, set the pilot mix screws at 2 1/2 turns out, floats are set to 27mm. A small amount of Permatex was applied to the bead area on the carb neck before installing. One airbox boot was tattered so I replaced it with a good one. There are no air leaks now, I checked all over with carb cleaner while running, it is air tight. The choke pistons are sealing well, the linkage is not holding them open. That's the good.
It starts on a 38 degree F morning with no choke at all, immediately goes to 3800 RPM and stays there for a couple minutes them slowly drops to a normal idle speed of say 1200-1500 or so, but wants to die. When throttle is applied it hesitates, it does not run smoothly, it is still on the rich side, the plugs are black after running at 3800 rpm for 4 minutes. This is a very low throttle position (just off idle). It still wont idle on it's own, though I never really got it to operating temperature yet. It was difficult to restart unless I waited for a time, and had to use WOT to get it to fire. It has spark and fuel at this time.
There were two changes since the last running: it was made richer by turning the mix screws out 1/2 turn from 2-turns. The throttle seals and/or carb boot do not suck air.
I'm leaning toward turning the mix screws in to 1 turn out to see if there is a positive change.
I welcome any thoughts , ideas, advice.....Thanks, gs450sjip

[gs450sjip]

Pete,

Please clarify the pilot jets on your bike. Were they originally with or without the side holes? I think some call them air bleeds. When you say too rich until you put the stock back in. I need cleared up on that, please. gs450sjip

Pete, Koolaid Kid and others,

I've done this for a year now, and I have gotten the details mixed up a couple times. Here's the latest:

The original pilot jets did NOT have the holes on the side, the ones in there now, DO have the holes. They are both 17.5 size. It runs rich..period. The exhaust burns your eyes.
I do NOT need a choke to start it in 38 degree weather. It runs fast immediately for two minutes, then slowly drops to 1200-1500 rpm, but tries to stall. When throttle is applied it stutters, runs rough, sounds terrible. I did hear it "sound healthy" in earlier tests. It requires WOT to restart. All symptoms are "rich". The fuel level is at the lowest level within spec, the floats, float, the needle and seats are new Mikuni. Everything is where it should be, except for maybe the pilot jets...I swapped them earlier, with no discernible difference, but that was before all the other issues were corrected. The mixture screws are at 1/2 turn out. There are no air leaks anywhere.
Where do I go from here? Well, change to the original pilot jets without the holes, if that don't work...I have a "For Sale" sign...

Thanks for the guidance...gs450sjip

[BigD_83]

I've been rereading this thread, and I noticed that (in this thread) there has been no talk of what's happening in the ignition system. I do know (from another thread) that you said you replaced the entire system with a Dynatek.

Question: did that include new coils or just the ignitor?

What kind of voltage are you currently getting at the coils? Has this changed since you acquired the motorcycle?

The pilot jets you have, are they both unmolested (i.e. not drilled out)?

Hopefully switching back to the hole-free jets will work for you. If not, it sounds to me like your problem MAY lie outside the carburetor.

[pete]

Sorry, I thought at some point you'd gone back to the stock pilots... and yes you should definitely do that, or get the other style in a smaller size.