Topic: 1981 cb650 choke question

[jmonda]

I just bought a Honda cb650 about 2 weeks ago.  It is all stock other then the paint.  I really do not know that much about bikes and am trying to learn.  The bike seems to run great and I have already put about 400 miles on it.  Anyway when I bought I noticed that attaches to the choke are some plastic spacer of varying sizes.  When I purchased the largest spacer was actually on the choke and to be honest I thought nothing of it. 

I was wondering if someone could tell me if this is a normal thing that people do or what.  I have taken the spacer out and pushed the choke all the way down and it runs fine after the bike is warmed up.

[cb650]

Sounds like someone was trying to keep it running rich.   That could explain you MPG.

[jmonda]

Thanks for the information.  The bike does seem to be running hotter since I pushed the choke in all the way.  I am not sure why.

[Hush]

Yup it will run like crap if the choke is not pushed all the way home.
I had the same model and the choke cable slipped on it's adjuster causing me untold headaches until I found the problem.
Welcome to the forum.....if you have a question about your bike, don't forget to add 650 in your question line and us 650 guys'n gals will know it's one of ours who needs help.

[jmonda]

Thanks.  That the thing though it really did not seem to run bad at all with the spacer on the choke it did get terrible gas mileage.  I will run another tank through with the choke pushed all the way in and see if it helps mpg.  However like I said now with the choke all the way in the bike seems to run hotter I have not had a chance to check the plugs and will do so shortly.

This is my first ever bike and I love it just want to make sure I am taking care of it right.  I have the Clymer manual but I do not know alot try to learn.

[Hush]

Don't worry too much about heat, as long as you have good oil and the right amount in the sump plus a clean air filter (if in doubt toss the old one, they look good but are full of microscopic blockages) you should be good to go.
Too much around town riding will also heat these 4 cylinder bikes up but won't hurt them, I like to take mine for a blast down a country road after a lot of town riding just to clear her throat.

[jmonda]

Thanks I drive 15 miles on the highway to my office speed limit is 70mph so no problem opening it up.  I am guessing the sump is the same as the oil pan/tank where you check the oil sorry for my ignorance.  PO said he put a new air filter in but I will check it out

[Hush]

Yup the only oil you have is in the sump on our bikes, if the dip stick says you have oil then it's all good.

[eurban]

Bike should run correctly with the choke fully down (off / no choke)  If it doesn't then you need to fix the problem (almost certainly in the carbs) that is causing this . . .One posibilty for the spacer is that the choke knob wouldn't stay up on its own, so the previous owner made a spacer to hold it up.  Many people do not know that there is a knurled adjuster nut underneath the rubber cover on the choke cable attachment point at the bracket near the handlebars.  Lift up the cover and tighten the knurled nut to increase the friction on the cable and keep it from self closing.  Have fun . . .

[jmonda]

Bike seems to run fine with the choke all the way down.  I just thought it seemed to be running a little hotter.  The choke knob stays up without any problems at all.  There are actually 3 different sizes of spacers attached to a string.  Hopefully I get a chance to pull the plugs and check everything out.

[jmonda]

Below is a response from the PO when I asked about the chokes and mileage.  Does this sound right?

The spacers on the choke are just my hick' solution to a cold choke cable.  When the weather gets colder, the choke wants  to open back up.  The spacers are on there for a staged warmup.  Probably not necessary right now.
Fuel mileage:  30 is about what I have always gotten.  It's pretty normal for fuel economies to be over stated in literature...40 might be possible on a new engine with a complete carb overhaul, but 30 sounds about right at the current juncture.

[cb650]

Yes it is a hick solution.  You can tighten up the resistance of the choke cable.  Someone already posted it.  I have 2 80's and 2 81's  and always got in the 50mpg range.  Ocasionaly in the 60.  So I'd say he gives "hick" a bad name.   

[jmonda]

but the choke seems to be working fine.  I pull it out when I first start it to be expected.  When it warms up I push it all the way in.  So do you think when i am pushing it all the way in it is not ging in?  Sorry I am just a bit confused.  I would think if the choke was staying open it would be idling high.

[cb650]

Not real sure of where the spacers was but if you removed them and its doing good check your mpg.  It would only be idling hi if the choke cam is adjusted properly anyway. Cant remember does it have pods or the stock airbox? 

[jmonda]

airbox is stock.  These spacers just are tied onto the actual choke with a string and there were like three of them.  ut he had it so the largest one was on there so the choke did not go all the way down.