Topic: Mo the 80 CB650 Custom: "As the Spanner Turns..."

[manjisann]

to test your lean theory, try the choke in little increments, saves pulling the carbs all the time.

I'll have to try that, I'm going on a ride after work today and will see if I can get this to work. I haven't really done much with the choke, to start her up I just go full choke, crank the throttle a bit and hit the button. She roars to life immediately and then choke off and from there it's just throttle control. Gotta remember, non standard carbs on my beauty 

About time you sorted that bucket of bolts out Brandon, we thought you were going tp make it your lifes' work for a while there. 

I'm an admitted tinkerer, but I must confess, it's about friggen time she was rideable. Just a wee bit more work on the A/F mixture and I'll have the carbs sorted and should be happy 

Bradon, them grey-haired gals in the pic figured your bike was runninng.. not baaaaaaad  !!.. 

Hahaha, shameless sheep jokes 

Thanks guys,

Brandon

[manjisann]

Went for another long ride today, trying to keep the rpms around 4k, I ended up with approx 35mpg. At this point I'm pretty much thinking that the 750 carbs with pods on this bike was not the best idea, at least where fuel economy is concerned. If I hadn't modified the tank unalterably I'd seriously consider going back to the stock configuration. GRRRR

Brandon

[Frankenkit]

if it helps, with iridium plugs on my stock 650 my plugs look like a cross between 20 and 21. http://www.dansmc.com/Spark_Plugs/Spark_Plugs_catalog.html

[manjisann]

Iridiums burn hotter right?  My plugs look pretty close to that too, but that's even after 5 minutes of idling (with a fan on the engine of course.) I'm just running the NGK D8EA (stock, I think that's the number) so I wonder if that makes a difference.

In another post someone said that running lean on our bikes (he said 500/750s, but I'm guessing we're still included) can rob us of 4-10 mpg, so I'm hoping that's part of it. I'm also hoping my front brake is grabbing a little still and putting the new rubber bushing on it will help. When you guys spin your front wheel by hand, how many revolutions can you get it to go? I know when the brake isn't mounted I can get many many more than 2.5, is this normal or indicates brake hangup? Anyone have any thoughts what would be causing this? I've rebuilt the MC, and Caliper, AND installed Braided Stainless Steel line. I've visually checked, with the caliper off the bike, when the brake handle is pumped and released the caliper moves back slightly, so it is withdrawing a bit.

What are my fellow 650 owners getting for MPG, TT said he'd read 50-60 mpg, is this true? At this point it's looking more and more like I'm going to have to admit that the carb mods I've made were perhaps not as beneficial as I'd originally hoped, and I'm not really in a position to go back to stock, so I would like to do what I can to ensure maximum mpg with what I've got.

Thanks,

Brandon

[manjisann]

On the way home my kickstand came down again and attempted to assassinate me. I swapped the spring I had on it for a shorer cb500 sidestand spring, and this is only the second time it has happened with this spring. I'm getting to the point where I'm tempted to take it off and only use the center stand, but it's not really practical.

Can someone with a 650 where the side stand spring attaches on the front please post me a closeup pic of the sidestand? I want to see how the spring is mounted to the frame. Mine originally had the spring attach on the back of the sidestand but due to the exhaust pipes not mounting right I had to chop the nub off and put a bolt on the front side to mount it to, and now I'm beginning to wonder if I oriented it wrong.

Thanks,

Brandon

[Hush]

Sounds like you mounted it wrong Brandon, those 81/82 650's also have that strange replaceable rubber bottom bit on the side stand, when it wears your bike gets lower and lower when parked.

[manjisann]

I checked my buddies kickstand spring and how it was mounted and there wasn't a ton of difference. I had mine mounted a little different so I changed it around, hopefully that will make a difference. Otherwise I either have to remove it and rely only on my centerstand, or come up with another way of securing it. I'm just crossing my eyes it works.

The little rubber bands came in for my brakes so I put the bike on the jack and spun the front wheel..... AND the stinker spun with no problems  Guess that isn't what's robbing me of fuel mileage. I may change it out anyhow and see what happens, it can't hurt.

I also dropped the clips on the needles down one notch to enrich it up a little. I rode her breifly and she seemed to respond a bit better, but I didn't ride long enough or hard enough to really tell.

I also increased the pressure in my tires to 32 psi front and 34 psi rear. This was suggested by a local bike shop, so I figured it is worth a shot to see if it will help with fuel mileage.


Brandon

[manjisann]

I don't know if the raised tire pressure has had any effect on mpg, but the bike feels sturdier and more solid, but it could all be in my head    Rode out to my sisters yesterday and the @#$%ing kickstand came down many times in that short jaunt. I had the choice of either going home and removing the dumb thing or finishing the trip and figuring something out when I got there. I chose the second. I took a metal coat hanger and basically wired the side stand to the muffler. Its kinda ghetto looking, but it allows me to keep the sidestand in case I need to use it, otherwise I'll just be using the centerstand.

I've decided not to sweat the mpg, it's still a lot better than my truck so I'll stop my sulking and just enjoy the ride Since I've never ridden a stock 650 I don't know if there's any gain in torque or acceleration, but I hope so, then I can use that to justify it 

I also ordered 45 slows, hopefully these are the last jets I have to order and will take care of the surging at low throttle opening.

Brandon

[Soos]

City MPG and highway MPG tend to be a bit different as well.

Recently I got 48.7mpg on a tank. Pure highway(and following 55mph construction zone limits) speeds.
About 188 miles on 3.86 gallons. About the highest so far with the current motor/carbs combo I have been running.
(a stock 550 cam with 61mm pistons in a cb650 motor, stock cb650 4-2 exhaust, and 32mm CV carbs)
However, around town I'll pull in the neighborhood of 40 mpg. lots of stop and go, possibly some idiling time tinkering with the bike etc.


You want better MPG, read up on hyper-milers.   A LOT of that they do are directly applicable to a motorcycle.
Some methods are not legal or safe mind you.(ie shutting off motor at highway speeds while going downhill)
But you can get an idea of minor things you can change in your driving habits to increase your MPG.
I use a few tips myself. Well worth it to my pocketbook.

l8r

[manjisann]

A few weeks ago I foolishly let my batteries electrolite levels drop and my bike let me know by stopping at a red light and not restarting. After topping up and charging the battery I got home and checked the bike. The charging system wasn't working right. Long story short, after fighting with it for two weeks and buying a spare RR from Soos (thanks man!) and a new Digital Multi Meter, I fixed the issue. What it finally took was cleaning a few of the contact points. The important thing is it seems to be working, so hooray!

Brandon

[manjisann]

Oh yeah, I also installed the 45 slows in and set the air screws to 1 turn out. I haven't pulled the plugs yet but my butt dyno says it's an improvement! She purrs like a kitten idling at 1k and pulls like a demon when the throttle is turned. I'll do some plug chops sooner or later, but for now I'm pleased with how she runs.

Brandon

[The_Crippler]

"Butt dyno."  Heh.

[manjisann]

I still haven't checked the battery or charging system, but I'm pretty sure the problem has been corrected! Special thanks again to Soos for the spare RR at such a good deal. And as always a huge thanks to this forum! She has been running like a champ other than the key cylinder going fubar, not sure what caused it, but ordered a new one from DennisKirk and it should hopefully be here by the end of the week. In the mean time I'm planning on a ride to Antelope Island as a bit of a shakedown. Today I'm going to change the oil, clean the bike a bit, and try and check everything. Next week I'm going on a couple day ride to central Utah to a family reunion and then just a bunch of riding. I'll be taking pictures and doing a ride report on my blog I made specially for trips, anyone want the url?

Brandon

[Hush]

Nice to hear you are going to get some saddle time Brandon, it's been a long haul for you but like many on here who thought they would never get to ride their machines it's finally happening.
Yes please put up the URL for us so we can see where you got to.

[Doctor_D]

Yeah, 25 pages, a long haul... but nice to hear that it seems to be sorted.

Here's to hoping my thread doesn't go past 10. 

[Hush]

I think either Kit or I hold the 650 build thread record.

[Soos]

HAHA... I think you are right Hush.



l8r

[Frankenkit]

we're just both chatty cathys.

[manjisann]

Ok, here's the URL for my blog, hope you guys enjoy it. http://manjisann.blogspot.com/

I'm currently sitting in my uncles house in Richfield, its about 170 miles south of Salt Lake. We had a family reunion down here and I figured it'd be the perfect time to get some miles on the old girl. The ride down went pretty good. I put a small windshield on the bike and the first tank after install was getting about 28mpg  That's about 10mpg less than what I was getting on the Antelope island trip I did last thursday. It caused me a lot of frustration and anxiety for a day, but I finally figured that after putting all this time and money into the bike, Dammit I'm gonna ride! I'll give more details of the ride in the blog. Several things happened before and after the trip down here that are a little frustrating, but I've decided to try not to sweat the small stuff and just enjoy the bike for what she is.

Keep the shiney side up!

Brandon

[Frankenkit]

...and what was wrong with your stock 650 carbs that 28mpg is preferable to 48-50?

...omg I'm sounding like TT.

[The_Crippler]

...and what was wrong with your stock 650 carbs that 28mpg is preferable to 48-50?

...omg I'm sounding like TT.

Sweet, bubbly, Buddha - Say it ain't so!!!

[Frankenkit]

any progress? I would expect running lean to boost our mpg- less gas = less gas used.  maybe they meant running lean meant a loss in hp?

[manjisann]

So after several tanks of gas I've found I'm averaging 38mpg or so. I've decided that the sweet spot is about 6k rpms, anything lower than that and my mpg's fall through the floor. As for why I decided to change carbs, at the time I was trying (key word there) to save some money, instead of paying to rebuild the stock 650 carbs. I've now realize that I've spent more to get these ones to work than if I'd have just stayed stock. So now I soothe my raw nerve by telling myself that she probably accelerates and is more responsive to the throttle than a stock bike. Whether that's true or not I honestly don't know, but it makes me feel a wee bit better. I'd go back to stock if it was an option, but with the tank mod it's pretty much out of the question. I've decided I'll just enjoy her as she is, and probably pick up a second bike (ok, a third one, I do still have the cafe that I'm working on) later on and leave it stock. I have learned a valuable lesson, I AM NOT SMARTER THAN A HONDA ENGINEER!  I will admit though, I want to see if I can't get these carbs to function better on this bike, so I'm sure I'll keep tinkering along the way.

On a side note, the engine has picked up a weird ticking noise along the way. I'm not totally sure what it is or even how to describe it. I'm crossing my fingers that it's nothing that can't wait to be addressed until I get home.

Brandon

[The_Crippler]

Amazing how that happens - you can talk yourself out of something (or let someone else talk you out of it) because of money, and then you either spend more on the alternative, or at very least, spend some cash before going back to what you wanted in the first place.  That's how it's going with my headlight.

[Frankenkit]

ha! oh. that reminds me of my 350...  It looked 'okay' with the stock seat, but I talked myself into getting a cafe seat... which didn't fit with the original tank, so then I got a new tank...