'76 idle bogs when blipping throttle
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Re: '76 idle bogs when blipping throttle
Again, the jet metering is generally controlled not just by hole diameter but the length as well as the entry and exit corners as well. It all has an effect on the metering. I do check the diameters with a precision set of pin gages which is the proper way to check them, calipers are not accurate enough on such small sizes but they’ll get you in the ball park, maybe. As a side note, Keihin jet sizes are that if you have a #120 it should be 1.20mm , the primary #62 main is .62mm. I have found Keihin jets to be really precise, but again the actual flow is the important thing and it is controlled by the hole diameter, the hole length & the entry & exit corner profiles.
Again, I don’t drill jets if a new properly sized jet is available, it’s a bad idea. But again your bike & your money. And I’ll add that you should never, ever drill the #35 idle jets, ever !
Again, I don’t drill jets if a new properly sized jet is available, it’s a bad idea. But again your bike & your money. And I’ll add that you should never, ever drill the #35 idle jets, ever !
Red 1976 oe owner
1976 LTD restored
1980 CBX , in the que, to fix the ignorant heavy handed owner
1981 CBX
1977 CB750 K7
2014 FJR OE owner, sold
1980 GL1100
1984 GL1200 naked
1969 CL350, in the que
1976 LTD restored
1980 CBX , in the que, to fix the ignorant heavy handed owner
1981 CBX
1977 CB750 K7
2014 FJR OE owner, sold
1980 GL1100
1984 GL1200 naked
1969 CL350, in the que
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Re: '76 idle bogs when blipping throttle
Yesterday, I checked some Kehin jets to make sure they were the right size and I found they were not. Two 120 air jets fit tight on my gauge and two fit loose on the gauge. They all were probably close enough, but instead of just installing these tight and loose jets as-is, I take a jet cleaner and fine tune the tight jets to match the loose jets. Doing this, at least all 4 are the same. You get a feel for this after doing many of these. My point is, you cannot trust the stamp even with Kehin jets and I have seen some of these that were not even close to being the right size. You mentioned the #35 jet and I agree with you on this one. I use a guitar "E" string to check this jet. I use it to clean the jet and also to check the size of the hole by feeling the resistance as you pull the wire through the jet. I use 4 with the same resistance in a carb set. I have done enough GL1000 carbs to know what is important and how to make them work properly. I think you are being too critical with the drill method, especially with air jets. The pilot jets I have drilled have worked just fine and it is an accepted practice by experts. I was corresponding with HondaMan (Mark Paris) the other day about carbs and he mentioned that he had to solder and re-drill emulsion tubes on a CB750 because the holes were too big. This guy knows a lot and if he drills emulsion tubes, it is ok. I have only had the need to drill the pilot air jets and emulsion tubes. I have also had good luck with third party jets, even the fuel jets. As long as they are the right size, I have found they work just fine and I am pretty picky.
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Re: '76 idle bogs when blipping throttle
With thanks again to cfairweather I received and have installed the new #59 idle air jets. Here's a video -
https://www.youtube.com/watch?v=-bBYKWmKMjQ
There's a definite improvement in terms of choke - the new set-up means a quicker warm-up time with less choke required. With regard to the off-idle situation, there's an improvement there too. Please bear in mind that I am little more than a shade-tree mechanic at best and so none of this should be taken as authoritative or professional at all and there's every possibility that there's a lot of room for improvement with these carbs in other departments (another synch for one thing, and the very significant detail that I have only ever owned this bike as a roller, never as a rider - it's never been under load with me grinning in the saddle).
That said, there is still some lag with throttle response, and still a bit of a flat spot. But it is crisper certainly. I'll be interested to hear what others have to say, especially those of you that have also done this mod.
https://www.youtube.com/watch?v=-bBYKWmKMjQ
There's a definite improvement in terms of choke - the new set-up means a quicker warm-up time with less choke required. With regard to the off-idle situation, there's an improvement there too. Please bear in mind that I am little more than a shade-tree mechanic at best and so none of this should be taken as authoritative or professional at all and there's every possibility that there's a lot of room for improvement with these carbs in other departments (another synch for one thing, and the very significant detail that I have only ever owned this bike as a roller, never as a rider - it's never been under load with me grinning in the saddle).
That said, there is still some lag with throttle response, and still a bit of a flat spot. But it is crisper certainly. I'll be interested to hear what others have to say, especially those of you that have also done this mod.
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Re: '76 idle bogs when blipping throttle
James- "#59" is the drill bit size. The actual jet size is about 105. I think you are going to have a nice bike after you get it fine tuned. The video was helpful. I could barely see the temp gauge but it looked like it was close to being warm when you made the video. If the GL1000 is not fully warmed up, it won't run good. Just a few observations:
1. You may need to add antifreeze.
2. The engine sounds pretty good except for the hesitation. If it does that when fully warm, you can improve it.
Everything must be perfect to make these bikes run at their best. If the weather cooperates, take the bike out on the highway for a ride at high speed to blow the cobwebs out and then take a look at the plugs.
3. Installing the air filter might help the response because it will run a bit richer.
4. If you have points and the original coils, wires, spark plug caps, consider replacing them with the Dyna or Dyna clones.
You can get the electronic ignition for under $50.00 and the Dyna clone coils for about $20.00 each. New NGK caps will cost about $8.00 each. Get new 7mm copper spark plug wires from a bulk roll at NAPA. They sell the ends and rubber ends too. This will cost about $15.00. So for around $100.00 you will have a big upgrade to your ignition system and it will help the bike run better. You also won't have to mess with points anymore and you will eliminate the ballast resistor. I have a detailed post on how to do this.
5. I hear some chatter, so check the valve clearance. Carefully follow the manual when you do this procedure. The bike will run at its best when these are set correctly. Also, as previously mentioned, replace the belts unless you are certain it has been done within the past few years.
6. You mentioned the carbs were rebuilt. Did you rebuild them or have someone do it for you? The slides must be polished and work perfectly.
Again, you will have a nice bike and I can tell you are pretty good at mechanics. We are all learning...
1. You may need to add antifreeze.
2. The engine sounds pretty good except for the hesitation. If it does that when fully warm, you can improve it.
Everything must be perfect to make these bikes run at their best. If the weather cooperates, take the bike out on the highway for a ride at high speed to blow the cobwebs out and then take a look at the plugs.
3. Installing the air filter might help the response because it will run a bit richer.
4. If you have points and the original coils, wires, spark plug caps, consider replacing them with the Dyna or Dyna clones.
You can get the electronic ignition for under $50.00 and the Dyna clone coils for about $20.00 each. New NGK caps will cost about $8.00 each. Get new 7mm copper spark plug wires from a bulk roll at NAPA. They sell the ends and rubber ends too. This will cost about $15.00. So for around $100.00 you will have a big upgrade to your ignition system and it will help the bike run better. You also won't have to mess with points anymore and you will eliminate the ballast resistor. I have a detailed post on how to do this.
5. I hear some chatter, so check the valve clearance. Carefully follow the manual when you do this procedure. The bike will run at its best when these are set correctly. Also, as previously mentioned, replace the belts unless you are certain it has been done within the past few years.
6. You mentioned the carbs were rebuilt. Did you rebuild them or have someone do it for you? The slides must be polished and work perfectly.
Again, you will have a nice bike and I can tell you are pretty good at mechanics. We are all learning...
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Re: '76 idle bogs when blipping throttle
Ah yes, of course, got myself mixed up there with the drill bit size and jet size, thanks for clarifying! Well, I've never actually ridden the bike so everything I've done to it has been up on the table. I did the carb clean following Randakk's how-to video - I've cleaned a few sets of carbs now (it's one of my favourite parts of working on a bike, weird I know) and while I appreciate the importance of doing a really thorough job I don't doubt that's there's room for me not to do a 100% job. As far as I know I did (close anyway) but I've buggered things up before and no doubt will again. But once I finally get the bike out on the road I'll do some plug chop tests and see what gives. I've also got a very helpful tool called a Color Tune - it's basically a spark plug with a window in it so you can see the colour of the combustion in the chamber.
I'll definitely look into replacing the existing (original) ignition system with something a bit more robust. I've never done this on any of my other bikes but I like the idea of experimenting with a Dyna set up. I like trying out new things with each bike I work on so this would be a great opportunity for that.
I have already done a valve clearance check and as far as I can tell they're on the money. But you're right, there is some chatter (I wasn't sure if it was a chain or something internal in the engine). Think I should check the valves again?
I've already replaced the belts - no way I could miss the importance of doing that after spending the first five minutes on this forum!
I'll definitely look into replacing the existing (original) ignition system with something a bit more robust. I've never done this on any of my other bikes but I like the idea of experimenting with a Dyna set up. I like trying out new things with each bike I work on so this would be a great opportunity for that.
I have already done a valve clearance check and as far as I can tell they're on the money. But you're right, there is some chatter (I wasn't sure if it was a chain or something internal in the engine). Think I should check the valves again?
I've already replaced the belts - no way I could miss the importance of doing that after spending the first five minutes on this forum!
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Re: '76 idle bogs when blipping throttle
James- I am sure you did a great job with the valves and carbs. Probably time to move on to other possibilities.
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Re: '76 idle bogs when blipping throttle
My man - your confidence in my abilities is very complimentary, and I hope when this bike is done that I live up to it!
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Re: '76 idle bogs when blipping throttle
Have you tried removing one carb elbow at a time , then the mixture screw then , spraying with solvent and blasting air back and forth through discharge nozzle and mixture screw port , because when cleaning the idle passage when your carb bowls are off is more difficult , idle fuel is a % of the fuel supply . mine has stronger response with clean idle discharge nozzles. Cheers.
76 GL1000 ,73 Norton mk5 , 75 Triumph T160 , 49 Matchless G80 500 rigid ,and
X4 76 HondaTL250s
X4 76 HondaTL250s
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Re: '76 idle bogs when blipping throttle
My belief is that if you put an airbox & filter on it along with some fresh gas and a seat and went for a ride you’d find it runs perfectly with no bogs or stumbles. Vacuum slide carbs just don’t have the response of a mechanical linkage with a accelerator pump that gives you that instant throttle.
Between the vacuum slide carbs and the heavy crank & flywheels I don’t believe you’ll see much better, but I could be wrong, but I’d welcome any videos showing any better. My .02
Between the vacuum slide carbs and the heavy crank & flywheels I don’t believe you’ll see much better, but I could be wrong, but I’d welcome any videos showing any better. My .02
Red 1976 oe owner
1976 LTD restored
1980 CBX , in the que, to fix the ignorant heavy handed owner
1981 CBX
1977 CB750 K7
2014 FJR OE owner, sold
1980 GL1100
1984 GL1200 naked
1969 CL350, in the que
1976 LTD restored
1980 CBX , in the que, to fix the ignorant heavy handed owner
1981 CBX
1977 CB750 K7
2014 FJR OE owner, sold
1980 GL1100
1984 GL1200 naked
1969 CL350, in the que
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Re: '76 idle bogs when blipping throttle
I do think Redglbx has the right idea.
Proud member of the NGW Cartel (Rochester MI)
1977 GL1000 BADDOG (April 2012 BOTM)
1976 LTD - '993 LTD...and so it begins'
You should remember that it's peace of mind you're after and not just fixing the machine. R.Pirsig
1977 GL1000 BADDOG (April 2012 BOTM)
1976 LTD - '993 LTD...and so it begins'
You should remember that it's peace of mind you're after and not just fixing the machine. R.Pirsig
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Re: '76 idle bogs when blipping throttle
I haven’t posted my recipe for tuning these old gals for a while … here it is
Fill with nice fresh gas … ride 200 miles … fill with nice fresh gas … ride 200 miles … fill with …
Gord
Fill with nice fresh gas … ride 200 miles … fill with nice fresh gas … ride 200 miles … fill with …
Gord
"I'd rather Ride than Shine"
‘14 KLR650 ... not a rat ... yet
‘84 GL1200i ‘R2B6' (Rat to Be 6, the last, adopted by twowings)
My Original 'RAT' was a hybrid '82 CB900/1100F
‘14 KLR650 ... not a rat ... yet
‘84 GL1200i ‘R2B6' (Rat to Be 6, the last, adopted by twowings)
My Original 'RAT' was a hybrid '82 CB900/1100F
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Re: '76 idle bogs when blipping throttle
Gord !
Red 1976 oe owner
1976 LTD restored
1980 CBX , in the que, to fix the ignorant heavy handed owner
1981 CBX
1977 CB750 K7
2014 FJR OE owner, sold
1980 GL1100
1984 GL1200 naked
1969 CL350, in the que
1976 LTD restored
1980 CBX , in the que, to fix the ignorant heavy handed owner
1981 CBX
1977 CB750 K7
2014 FJR OE owner, sold
1980 GL1100
1984 GL1200 naked
1969 CL350, in the que
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Re: '76 idle bogs when blipping throttle
A half decent 1100 wiil get 50 mph … a 1000? not so much …
Gord
Gord
"I'd rather Ride than Shine"
‘14 KLR650 ... not a rat ... yet
‘84 GL1200i ‘R2B6' (Rat to Be 6, the last, adopted by twowings)
My Original 'RAT' was a hybrid '82 CB900/1100F
‘14 KLR650 ... not a rat ... yet
‘84 GL1200i ‘R2B6' (Rat to Be 6, the last, adopted by twowings)
My Original 'RAT' was a hybrid '82 CB900/1100F
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Re: '76 idle bogs when blipping throttle
I have seen 48-50 on my 78. But granted, not always
1978 custom GL1000
1977 custom with 1200 engine
1985 gl1200
1977 custom with 1200 engine
1985 gl1200
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