Author Topic: "Help Juntjoo fix his CB650!" thread  (Read 15784 times)

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Offline juntjoo

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #50 on: February 12, 2018, 02:04:16 PM »
This is a 500/550 advancer but the concept is the same. Rev the engine up and adjust the plate so the notch on the case lines up between the blue and green marks in the picture. Forget where it falls at idle.

thank you! and I'm gonna trust you over the book but why don't we worry about idle, and what exactly is the mark for idle anyway if not the mark above the "T"?

Clymer timing steps https://imgur.com/a/fMif5
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline Scott S

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #51 on: February 12, 2018, 04:22:57 PM »
 You spend most of your time under throttle. You want the timing to be correct at full advance. Let the idle timing fall where it may.
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline juntjoo

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #52 on: February 12, 2018, 07:40:19 PM »
You spend most of your time under throttle. You want the timing to be correct at full advance. Let the idle timing fall where it may.

gotcha ;)
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline juntjoo

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #53 on: February 15, 2018, 05:16:14 AM »
here I repair my boots with "shellac":


re-clean my jets and swap parts of working cylinders with non-firing ones:


and finally I test it out with great results, kinda...


key things:

something between "shellackin'" boots &
torching jets(producing smoke from both 1&3 slow jets particularly),
got 1&3 cylinders started firing.  But...
fuel overflowed into vent line &
engine idled really high and threatened to automatically redline til I killed it
floats, I only swapped them between carbs.
and now it won't start. so that's it. thanks
« Last Edit: February 15, 2018, 03:06:17 PM by juntjoo »
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline juntjoo

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #54 on: February 15, 2018, 01:29:29 PM »
So I can start it if I take out a plug or two and torch them real quick, but engine is idling high and wants to die and is smoking from bottom of engine and pipes, where there is a lot of condensation.

no more overflow into the vent lines(good thing I used transparent tubing!)

at this point I can't really do anything with timing or idle, unless someone helps me, perhaps jist to put either in a safe starting point.

what do I do with the idle knob? when I turned it all the way in at a certain point as if it uncovered a hole it rapidly increased idle speed, so I backed it out but it seemed to go on for infinity, so now it's somewhere in deep space and I don't know where to put it but I know back close it just makes the problem worse.

the slow jets I torched I highly doubt have opened more than they were made to as after cleaning them I only noticed the E wire having less resistance on the 1&3, the ones that smoked when torched, but no MORE open than 2&4, just a really good smooth fit. The primary jets, didn't have a perfect probing wire to gauge their size but I just torched them the same. Although I'm thinking a swapping of these with the brand new replacements from my rebuild package is in order here but have heard stock jets are best to keep if possible, + it'll be a pain to go back in there. Although, if I do you can do it while carbs installed no? Just need slim fingers and small tools right?

Otherwise is there anything else anyone can think of?
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline Scott S

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #55 on: February 15, 2018, 03:30:34 PM »
 Sounds like you need to reset the idle screw and bench sync the carbs. Unfortunately,  that means pulling the carbs again.
 Just because the pilot JETS are clean doesn't necessarily mean that the pilot CIRCUITS are clean.
 Do your carbs have the accelerator pump circuit? Those things were a PITA to get clear on the set I had.
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline juntjoo

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #56 on: February 15, 2018, 04:42:37 PM »
Sounds like you need to reset the idle screw and bench sync the carbs. Unfortunately,  that means pulling the carbs again.
 Just because the pilot JETS are clean doesn't necessarily mean that the pilot CIRCUITS are clean.
 Do your carbs have the accelerator pump circuit? Those things were a PITA to get clear on the set I had.

thanks. I doubt I need to bench sync again, as nothing with the throttle has changed since I last bench synced, AFAIK. So I'll put that down the list and I think I kinda got the idle as I screwed it all the way in then backed out a bit by bit while checking the slight movement of the throttle pulley when closing the choke. But I also adjusted the knob while the bike was idling and it didn't appear to have any effect.

unless any other ideas come up I think I'll try swapping all brass out for the new ones, and if no difference then I'll just have to take em down again. good news is I'll be faster next time! but hey, got my spark and fuel on all four now! getting close!
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline juntjoo

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #57 on: February 16, 2018, 03:30:05 PM »
Sounds like you need to reset the idle screw and bench sync the carbs. Unfortunately,  that means pulling the carbs again.
 Just because the pilot JETS are clean doesn't necessarily mean that the pilot CIRCUITS are clean.
 Do your carbs have the accelerator pump circuit? Those things were a PITA to get clear on the set I had.

about those "circuits" you speak of, I was able to shoot carb spray through from the screw side to the carb throat as it's like right there but I think you're talking about deeper in there, where it routes to the fuel. Is that ever an issue? And how does one get in there? I'm guessing there isn't a way. I may not need to but in case I do I wanted to ask

compressed air through the slow jet from the bowl side?
« Last Edit: February 16, 2018, 08:40:28 PM by juntjoo »
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline Scott S

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #58 on: February 17, 2018, 04:27:48 AM »
 Ultrasonic cleaner. Sometimes, a professional carb service is what it takes. Those are tiny, tiny circuits.
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline Yamahawk

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #59 on: February 17, 2018, 04:38:43 AM »
+1 on the ultrasonic cleaning, I have had success in cleaning idle circuitry by removing the mixture screws, squirting carb cleaner into them, and then blowing out with an air compressor and a rubber tipped air blower. If you can see cleaner coming out of the small passages inside the throat of you carbs, then you know it is passing fuel. The hardest thing to clean are the small orifices in the pilot jets. They are so small, that they clog very easily, and you might only see a pinhole of light, when you should see a bit more. If you get new pilots and look through them, then compare to your old ones, you will notice a BIG difference in the orifice. Sometimes, it can be necessary to replace them, if the deposits are so stubborn that you can't get them clean...even when poking with a very small wire...
Charlie
1971 CB750K1 (newest bike), 1996 Royal Enfield 500 Bullet (therapy bike), 1981 Yamaha XV920RH, 2006 Kawasaki Concours (retirement bike), 1975 Yamaha RD350 (race bike), 1989 Honda VTR250 Interceptor (race bike), 1986 Kawasaki EX250 Ninja (race bike in progress), 1985 Honda Elite CH250, 1973 Yamaha GT1 80cc, 1974 Yamaha DT360 project bike.

The Only Thing Necessary for Evil to Triumph, is for Good Men to do Nothing.
Edmund Burke

All Things work together for good, for those who love God and are the Called according to His purpose.
Romans 8:28

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Job 13:15
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Offline juntjoo

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #60 on: February 17, 2018, 07:10:23 AM »
+1 on the ultrasonic cleaning, I have had success in cleaning idle circuitry by removing the mixture screws, squirting carb cleaner into them, and then blowing out with an air compressor and a rubber tipped air blower. If you can see cleaner coming out of the small passages inside the throat of you carbs, then you know it is passing fuel. The hardest thing to clean are the small orifices in the pilot jets. They are so small, that they clog very easily, and you might only see a pinhole of light, when you should see a bit more. If you get new pilots and look through them, then compare to your old ones, you will notice a BIG difference in the orifice. Sometimes, it can be necessary to replace them, if the deposits are so stubborn that you can't get them clean...even when poking with a very small wire...
Charlie

I thought these were the pilot screws with the jets just being the opening above them going right into the throat.

what screw is this? https://imgur.com/a/IjVk9

anyone know of a link to something/place/video/whatever that explains all the parts and functionality of our carbs? would be great if there was like a single page of this info
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline juntjoo

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #61 on: February 17, 2018, 04:10:31 PM »
well new jets, the brass ones, the only insertable ones for my my carbs didn't change anything so I'm going to start with spark plugs caps and wires. Never bought those for any vehicle actually and learned that they are specifically made for each vehicle but I wonder if I could just grab any set from the local auto parts place for a vehicle that has them long enough and to fit compatible plugs so I can just cut them down to size? yay? nay?
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline Scott S

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #62 on: February 17, 2018, 04:14:22 PM »
+1 on the ultrasonic cleaning, I have had success in cleaning idle circuitry by removing the mixture screws, squirting carb cleaner into them, and then blowing out with an air compressor and a rubber tipped air blower. If you can see cleaner coming out of the small passages inside the throat of you carbs, then you know it is passing fuel. The hardest thing to clean are the small orifices in the pilot jets. They are so small, that they clog very easily, and you might only see a pinhole of light, when you should see a bit more. If you get new pilots and look through them, then compare to your old ones, you will notice a BIG difference in the orifice. Sometimes, it can be necessary to replace them, if the deposits are so stubborn that you can't get them clean...even when poking with a very small wire...
Charlie

I thought these were the pilot screws with the jets just being the opening above them going right into the throat.

what screw is this? https://imgur.com/a/IjVk9

anyone know of a link to something/place/video/whatever that explains all the parts and functionality of our carbs? would be great if there was like a single page of this info

 Hard to see exactly what you're holding there, but if it has a pointy needle like tip and is threaded, that's the mixture screw. It affects all circuits to some degree, but especially the idle and low speed functions. It's not the same as the pilot jet....which is also often called the slow jet or low speed jet.
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline evinrude7

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #63 on: February 17, 2018, 04:16:41 PM »
well new jets, the brass ones, the only insertable ones for my my carbs didn't change anything so I'm going to start with spark plugs caps and wires. Never bought those for any vehicle actually and learned that they are specifically made for each vehicle but I wonder if I could just grab any set from the local auto parts place for a vehicle that has them long enough and to fit compatible plugs so I can just cut them down to size? yay? nay?

juntjoo you probably need 5K resistor caps.  like these.  check the manual or bike specs.  https://www.ebay.com/itm/HONDA-CB650-CB750-CB900-CB1100-SPARK-PLUG-CAPS-/291732014119  stop looking at the women. 

carb learning https://www.4shared.com/web/preview/pdf/jC4Zzkqhce
« Last Edit: February 17, 2018, 04:22:22 PM by evinrude7 »
cb750 k6 - ugly

Offline juntjoo

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #64 on: February 17, 2018, 04:31:19 PM »
+1 on the ultrasonic cleaning, I have had success in cleaning idle circuitry by removing the mixture screws, squirting carb cleaner into them, and then blowing out with an air compressor and a rubber tipped air blower. If you can see cleaner coming out of the small passages inside the throat of you carbs, then you know it is passing fuel. The hardest thing to clean are the small orifices in the pilot jets. They are so small, that they clog very easily, and you might only see a pinhole of light, when you should see a bit more. If you get new pilots and look through them, then compare to your old ones, you will notice a BIG difference in the orifice. Sometimes, it can be necessary to replace them, if the deposits are so stubborn that you can't get them clean...even when poking with a very small wire...
Charlie

I thought these were the pilot screws with the jets just being the opening above them going right into the throat.

what screw is this? https://imgur.com/a/IjVk9

anyone know of a link to something/place/video/whatever that explains all the parts and functionality of our carbs? would be great if there was like a single page of this info

 Hard to see exactly what you're holding there, but if it has a pointy needle like tip and is threaded, that's the mixture screw. It affects all circuits to some degree, but especially the idle and low speed functions. It's not the same as the pilot jet....which is also often called the slow jet or low speed jet.

confusing as in my Clymer manual the pilot screw is the the one picture, that you glue the cap onto that you adjust from outside the carb, on the front side, being the type that adjust fuel in the mix, as I believe you explained, which I didn't replace since it's functionality seems to come down to the tip which is simply cleanable to male work right.

so I have that screw, for each carb then my main idle screw/black plastic knob for adjusting idle, then two brass insertable jets, the main one, big long tube one where the bowl side end screws on, then  the other smaller(tube)  jet I think is the "slow speed" jet. I tell you these terms, slow speed, secondary, primary, main secondary, I think tue 750 and 1000 cv's have an extra jet... mine have that third tube in the bowl(within the sand castle shaped arrangement) blocker completely, not used I presume I'm guewsing where the other bikes of same carb cast would have the extra jet my manual makes no mention of... Can't keep up!
« Last Edit: February 17, 2018, 04:33:49 PM by juntjoo »
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline juntjoo

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #65 on: February 17, 2018, 04:38:52 PM »
well new jets, the brass ones, the only insertable ones for my my carbs didn't change anything so I'm going to start with spark plugs caps and wires. Never bought those for any vehicle actually and learned that they are specifically made for each vehicle but I wonder if I could just grab any set from the local auto parts place for a vehicle that has them long enough and to fit compatible plugs so I can just cut them down to size? yay? nay?

juntjoo you probably need 5K resistor caps.  like these.  check the manual or bike specs.  https://www.ebay.com/itm/HONDA-CB650-CB750-CB900-CB1100-SPARK-PLUG-CAPS-/291732014119  stop looking at the women. 

carb learning https://www.4shared.com/web/preview/pdf/jC4Zzkqhce

thanks. What women? where?

okay, check specs for caps, get ones that fit plugs(check specs?) that fit bike, then wires? are spark plug wires just spark plug wires or... Yeah, I'd like to be able to pick something up tonight if possible.
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline Yamahawk

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #66 on: February 17, 2018, 05:27:19 PM »
Don't get carbon core spark plug wires, get copper strand core wires. And 5k ohm resistor spark plug caps. The tips of those needles go into holes... those holes are what lead to the passages that you will squirt carb cleaner into, then blow out with compressor and tool. The pilot jets are removed, then the holes they fit in are treated the same way. Clean the pilot jets and try to see through them long ways. If you see a nice hole, no problem.. if you can't see through them, or if you can only see a pinpoint of light, then clean them.
Charlie
1971 CB750K1 (newest bike), 1996 Royal Enfield 500 Bullet (therapy bike), 1981 Yamaha XV920RH, 2006 Kawasaki Concours (retirement bike), 1975 Yamaha RD350 (race bike), 1989 Honda VTR250 Interceptor (race bike), 1986 Kawasaki EX250 Ninja (race bike in progress), 1985 Honda Elite CH250, 1973 Yamaha GT1 80cc, 1974 Yamaha DT360 project bike.

The Only Thing Necessary for Evil to Triumph, is for Good Men to do Nothing.
Edmund Burke

All Things work together for good, for those who love God and are the Called according to His purpose.
Romans 8:28

Though He slay me, Yet will I trust Him...
Job 13:15
will you trust Him...?

Offline evinrude7

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #67 on: February 17, 2018, 05:48:51 PM »
well new jets, the brass ones, the only insertable ones for my my carbs didn't change anything so I'm going to start with spark plugs caps and wires. Never bought those for any vehicle actually and learned that they are specifically made for each vehicle but I wonder if I could just grab any set from the local auto parts place for a vehicle that has them long enough and to fit compatible plugs so I can just cut them down to size? yay? nay?

juntjoo you probably need 5K resistor caps.  like these.  check the manual or bike specs.  https://www.ebay.com/itm/HONDA-CB650-CB750-CB900-CB1100-SPARK-PLUG-CAPS-/291732014119  stop looking at the women. 

carb learning https://www.4shared.com/web/preview/pdf/jC4Zzkqhce

thanks. What women? where?

okay, check specs for caps, get ones that fit plugs(check specs?) that fit bike, then wires? are spark plug wires just spark plug wires or... Yeah, I'd like to be able to pick something up tonight if possible.

women in ebay link.  see if there is a napa autoparts store near you and call.  tell them the application you need them for. 
cb750 k6 - ugly

Offline evinrude7

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #68 on: February 17, 2018, 05:52:34 PM »
How to get a large seized philips head scew out. https://imgur.com/a/pOOyY

it's probably a JIS head on that screw.  japanese industry standard.  it's a more squared version of a phillips. 
cb750 k6 - ugly

Offline juntjoo

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #69 on: February 17, 2018, 06:12:19 PM »
How to get a large seized philips head scew out. https://imgur.com/a/pOOyY

it's probably a JIS head on that screw.  japanese industry standard.  it's a more squared version of a phillips.

thanks. already got those a while back. look like the same ones on top of the carbs. I oughta replace those too with hex head bolts. Home depot had em for my carb bowls. under $4 total. up to $20 on ebay. woo hoo!
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.

Offline Scott S

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #70 on: February 17, 2018, 06:31:45 PM »
 $46 for spark plug caps?!?!? Holy crap, you can get them way cheaper than that.
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline evinrude7

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #71 on: February 17, 2018, 06:59:27 PM »
$46 for spark plug caps?!?!? Holy crap, you can get them way cheaper than that.

i wasn't looking at the price.   ::)
cb750 k6 - ugly

Offline Scott S

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #72 on: February 18, 2018, 04:40:13 AM »
$46 for spark plug caps?!?!? Holy crap, you can get them way cheaper than that.

i wasn't looking at the price.   ::)

 They better come with a happy ending at that price.
'71 CB500 K0
'17 Triumph Street Scrambler
'81 Yamaha XS650

Offline evinrude7

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #73 on: February 18, 2018, 07:07:12 AM »
$46 for spark plug caps?!?!? Holy crap, you can get them way cheaper than that.

i wasn't looking at the price.   ::)

 They better come with a happy ending at that price.

better check the fine print. 
cb750 k6 - ugly

Offline juntjoo

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Re: "Help Juntjoo fix his CB650!" thread
« Reply #74 on: February 18, 2018, 08:03:29 AM »
well new jets, the brass ones, the only insertable ones for my my carbs didn't change anything so I'm going to start with spark plugs caps and wires. Never bought those for any vehicle actually and learned that they are specifically made for each vehicle but I wonder if I could just grab any set from the local auto parts place for a vehicle that has them long enough and to fit compatible plugs so I can just cut them down to size? yay? nay?

juntjoo you probably need 5K resistor caps.  like these.  check the manual or bike specs.  https://www.ebay.com/itm/HONDA-CB650-CB750-CB900-CB1100-SPARK-PLUG-CAPS-/291732014119  stop looking at the women. 

carb learning https://www.4shared.com/web/preview/pdf/jC4Zzkqhce

thanks again. didn't notice the carb guide the 1st time. can't download it tho. "Rejected Clicks
Platform Not Matched" but as long as it's still there I'll have it bookmarked. never saw the ladies you guys warned me about tho. must have been a temporary pop up ad or something. maybe I can find something on the internet here to suffice...
-Ben

82 Nighthawk 650..

1982 Honda Nighthawk...

I HAVE A 1982 HONDA NIGHTHAWK FFS! j/k. It's my only bike, my first and last.