Carb questions
#1
Carb questions
I recently purchased a 1990 Tour Glide with 27k miles. It is very stock.
It is running rich and has fouled the plugs. I can change the plugs, but would like to address why it is running rich. My first question is, do I need to adjust the mixture screw? It still has the plug covering it and it makes me wonder how it would be out of adjustment. Does it just need a good cleaning to get it back to where it needs to be?
I had it backfire through the carb and burned a hole in the air filter and melted some of the plastic back plate. This seems very dangerous to me. How common is this and is it related to the rich mixture? Couldn't this ignite the oil that makes its way into the air cleaner assembly?
Leads to my last question... When I removed the plastic air cleaner back plate I expected the two bolts holding the plate to the heads to be banjo bolts. They are not, they are solid. Doesn't this need to let the crankcase breath? The bolts looks stock. Anyone else have solid bolts?
Thanks!
It is running rich and has fouled the plugs. I can change the plugs, but would like to address why it is running rich. My first question is, do I need to adjust the mixture screw? It still has the plug covering it and it makes me wonder how it would be out of adjustment. Does it just need a good cleaning to get it back to where it needs to be?
I had it backfire through the carb and burned a hole in the air filter and melted some of the plastic back plate. This seems very dangerous to me. How common is this and is it related to the rich mixture? Couldn't this ignite the oil that makes its way into the air cleaner assembly?
Leads to my last question... When I removed the plastic air cleaner back plate I expected the two bolts holding the plate to the heads to be banjo bolts. They are not, they are solid. Doesn't this need to let the crankcase breath? The bolts looks stock. Anyone else have solid bolts?
Thanks!
#2
Join Date: Jan 2011
Location: Haslet Texas
Posts: 21,008
Likes: 0
Received 4,361 Likes
on
1,953 Posts
I recently purchased a 1990 Tour Glide with 27k miles. It is very stock.
It is running rich and has fouled the plugs. I can change the plugs, but would like to address why it is running rich. My first question is, do I need to adjust the mixture screw? It still has the plug covering it and it makes me wonder how it would be out of adjustment. Does it just need a good cleaning to get it back to where it needs to be?
I had it backfire through the carb and burned a hole in the air filter and melted some of the plastic back plate. This seems very dangerous to me. How common is this and is it related to the rich mixture? Couldn't this ignite the oil that makes its way into the air cleaner assembly?
Leads to my last question... When I removed the plastic air cleaner back plate I expected the two bolts holding the plate to the heads to be banjo bolts. They are not, they are solid. Doesn't this need to let the crankcase breath? The bolts looks stock. Anyone else have solid bolts?
Thanks!
It is running rich and has fouled the plugs. I can change the plugs, but would like to address why it is running rich. My first question is, do I need to adjust the mixture screw? It still has the plug covering it and it makes me wonder how it would be out of adjustment. Does it just need a good cleaning to get it back to where it needs to be?
I had it backfire through the carb and burned a hole in the air filter and melted some of the plastic back plate. This seems very dangerous to me. How common is this and is it related to the rich mixture? Couldn't this ignite the oil that makes its way into the air cleaner assembly?
Leads to my last question... When I removed the plastic air cleaner back plate I expected the two bolts holding the plate to the heads to be banjo bolts. They are not, they are solid. Doesn't this need to let the crankcase breath? The bolts looks stock. Anyone else have solid bolts?
Thanks!
What jets are in it? They may be too big.
Is it a CV carb?
On a '90 it should be a bottom breather so you shouldn't have any oil in air cleaner.
Also with a bottom breather the bolts going into the heads will be solid because it vents down below.
#3
Your bike is what is referred to as a "bottom breather." The breather is at the bottom, towards the middle from the oil pump, as God intended it to be. Yes, the bolts are solid and not banjo because that's not the breather. Oh, and just to cover it for when you will eventually ask, yes, it is normal for oil to puke out the breather if you let the bike sit for several weeks to months.
Now, for your carb issue, first check for intake leaks. Next throw away that POS carb and put a S&S or a CV on there and you will solve the majority of your problems. Or if you insist on keeping the Keihin POS, rebuild it and you can get it to run poorly to fair (if you're really good.)
Now, for your carb issue, first check for intake leaks. Next throw away that POS carb and put a S&S or a CV on there and you will solve the majority of your problems. Or if you insist on keeping the Keihin POS, rebuild it and you can get it to run poorly to fair (if you're really good.)
#4
Thank you for the quick replies! Glad to hear that someone didn't just plug up the breather holes!
How can I tell what carb I currently have? I believe it is a CV.
And a follow up question: when the plastic melted, there were little black chunks on the inside of the air filter. Should I be concerned that these particles could have gotten into the carb and the engine?
Thanks again.
How can I tell what carb I currently have? I believe it is a CV.
And a follow up question: when the plastic melted, there were little black chunks on the inside of the air filter. Should I be concerned that these particles could have gotten into the carb and the engine?
Thanks again.
#5
Look down the carb throat. Is there a butterflly flap or a slide that goes up and down? Slide thingie is CV. If you have a CV on there now, it may just need a thorough going through and some tuning. I don't do CV's, but there's lots here who do. Sounds like you do need a new air cleaner. Maybe someone has a takeoff if your budget constrained, or there's lots of aftermarket options.
If the bike is running, I wouldn't worry about the bits of plastic. Do fix that, though.
If the bike is running, I wouldn't worry about the bits of plastic. Do fix that, though.
#6
that bike has not been used and has been sitting for years - intake seals and a new set of jets - post up what is in it and the guys will tell you if they are correct, 2 jets are what your looking for - you need to buy the factory PARTS and SERVICE books as the names of what the exact part is called will go a long way in helping you
#7
Now, for your carb issue, first check for intake leaks. Next throw away that POS carb and put a S&S or a CV on there and you will solve the majority of your problems. Or if you insist on keeping the Keihin POS, rebuild it and you can get it to run poorly to fair (if you're really good.)
The bike already has a CV carb on it, the OP says the bike is very stock...
`90 was the first year for the CV carb (on the big twins).
It may be running rich because the carb is overflowing due to crud in the needle and seat.
Remove the carb and intake manifold, clean carb and reinstall manifold using new seals.
Why can`t I ever come across an almost new old bike like this.......
Last edited by Dan89FLSTC; 09-16-2014 at 06:01 PM.
Trending Topics
#8
that bike has not been used and has been sitting for years - intake seals and a new set of jets - post up what is in it and the guys will tell you if they are correct, 2 jets are what your looking for - you need to buy the factory PARTS and SERVICE books as the names of what the exact part is called will go a long way in helping you
175 to 180 main jet and a 45 slow jet will get you in the ball park but when you take it apart (heed the warning about having a manual before you start), let us know what your stock jets are.
With that kind of spitting back/backfire in the carb, you may have issues with the soft rubber diaphragm or the plastic part on the vacuum piston (maybe melted).
Here is an example of the replacement bolts and you may be able to find them at a good local hardware store, just pay attention to the size of the flange:
https://www.denniskirk.com/diamond-e...prd/271383.sku
And here are a few related links to your carb and supplies:
http://www.cv-performance.com/instructions-guides/
https://www.google.com/?gws_rd=ssl#q...v+carb+rebuild
Good luck! YD
#9
#10
Welcome aboard,
Tom