Wrestling with the airbox.

If it's broken or just needs tweaked

Moderators: Volker_P, tidd650

Spyug53
Posts: 75
Joined: Sat Dec 07, 2013 11:30 am
Location: Hamilton, Ontario, Canada

Wrestling with the airbox.

Postby Spyug53 » Sun Mar 22, 2015 4:17 pm

I apologize if this has been covered but I have been unable to fine anything on this issue.

So stock PD 50 carbs going back on after cleaning. I can get the carbs back on easily enough if the airbox plenum is removed. However it is damn near impossible to get the carbs into position if the plenum and boots are in position. There is just not sufficient room to maneuver. Even loosening off the airbox gains no clearance.

I tried removing airbox and plenum, hanging on the carbs and trying to get the airbox and plenum back in position but the plenum will not clear the frame with the carbs bolted up.

Any suggestions?

I spent 4 fruitless hours this afternoon trying to find a way but there does not seem to be an easy solution.

So at this point, any thoughts, ideas or suggestions would be welcomed.

Cheers
"Slowest beasts are always strongest and Manage to live the longest".
"If it's no Scottish, it's crap".

cb650
Posts: 2959
Joined: Fri Mar 03, 2006 7:20 am
Location: Denver CO USA
Contact:

Re: Wrestling with the airbox.

Postby cb650 » Sun Mar 22, 2015 4:22 pm

Airbox in first. Keep everything loose. Strap airbox back till u think youll break something. Carbs will go in. Still a bitch but doable. Threads with pics here somewhere.
Did you clean the tank out?!?!?!?!

User avatar
Folsoml
Posts: 1634
Joined: Sat Apr 07, 2012 9:02 pm
Location: North Florida

Re: Wrestling with the airbox.

Postby Folsoml » Mon Mar 23, 2015 5:05 am

Try a piece of sheet metal between the carbs and the airbox. The carbs will slide little better and not hang up on the airbox insulators.
Have a problem with your CB650? Have a technical question? Click here!


My Current Bikes: 2005 HD FLHTCUI Electra Glide Ultra Classic, 2007 Yamaha Vino,

Spyug53
Posts: 75
Joined: Sat Dec 07, 2013 11:30 am
Location: Hamilton, Ontario, Canada

Re: Wrestling with the airbox.

Postby Spyug53 » Mon Mar 23, 2015 8:37 am

Thanks guys.

I've replaced carbs on many bikes and I always thought the airboxes on Suzuki GSs were the worst. New worst...Honda CB 650 :mrgreen:

They are really awkward. Even pushing things back as CB suggests didn't work for me. There is just no give in the plenum when hard up against the frame.

I can see why so many folks go to pods or other types of filters. I was sorely tempted myself but know how darned difficult they can be to set up and run. I spoke with my buddy, the previous owner and he told me the bike had pods when he bought it and it never ran right. Ran so badly, in fact he went out and sourced a complete stock setup. But he had some "pros" put it on, ha,ha.

Well he is coming over this week to help and between the 2 of us we should be able to figure it out.......I hope :oops:

I'll let you know how it goes.
Cheers
"Slowest beasts are always strongest and Manage to live the longest".
"If it's no Scottish, it's crap".

Spyug53
Posts: 75
Joined: Sat Dec 07, 2013 11:30 am
Location: Hamilton, Ontario, Canada

Re: Wrestling with the airbox.

Postby Spyug53 » Sun Mar 29, 2015 3:34 pm

Well I put 4 hours in yesterday and did manage to get the carbs into position between the airbox plenum and the intake manifolds. No special secret just "brute force and ignorance" as my late departed dad would say.

Getting the carbs back on to the manifolds, however, was an exercise in shear frustration. No amount of tightening of ratchet straps would pop them on even with some heating of the rubbers. I gave up in disgust.

Thinking about it this morning, I realized that the rubber would need more heat to get them soft enough. Thinking about how to get more heat to the area, I realized it could be simple enough. Apply heat to the metal clamp and it would conduct all the way around the manifold in exactly the necessary area.....the throat.

So I reattached my ratchet straps with one around the top of the carb rack and another around the top of the float bowls. with them in position I heated the clamp on #1 with my heat gun touching the clamp and held there for 2 to 3 minutes. A slight tightening of the ratchets and in she popped.

I repeated the heating procedure with #2 and to help it in to position placed the hickory handle of a hammer just to the side of the carb on the backing plate and gave it a sharp tap with a mallet. In she popped as did 3 and 4 right after.

Two minutes after tightening all the clamps the plenum was back on then a few minutes more and the airbox itself was in position and tightened down.

So now I have everything back in place for re testing.

Hopefully my carbs will no longer leak and she will run well enough for me to synch the carbs.

I'll let you know when that happens.

Cheers.
"Slowest beasts are always strongest and Manage to live the longest".
"If it's no Scottish, it's crap".

my79650
Posts: 643
Joined: Tue Apr 06, 2010 11:37 am
Location: Gagetown, New Brunswick Canada

Re: Wrestling with the airbox.

Postby my79650 » Mon Mar 30, 2015 1:49 am

Glad you got it together. That was also my issue but you learn as you go and it will get easier for you.

Spyug53
Posts: 75
Joined: Sat Dec 07, 2013 11:30 am
Location: Hamilton, Ontario, Canada

Re: Wrestling with the airbox.

Postby Spyug53 » Mon Mar 30, 2015 8:33 am

and it will get easier for you.



Truer words were never spoke.

For all the newbies this is so true. The first time you do anything on a bike....or for that matter....in life in general, it can be daunting. The more you do something the easier it does get.

Despite years of working on auto carbs of all types, I always had a nervous feeling about bike carbs, preferring to pass them on to the pros for sorting. Maybe it was the idea of multiple carbs ganged together and needing to be "synched" or maybe it was the thought of losing one small piece or forgetting to put something back in place, I'm not sure.

My fear and trepidation was soon overcome when the XV500 Virago I picked up as a junker for my first restoration needed carb attention to get running and the budget had no room for a pro cleaning. Fortunately just a pair but oddly mounted ( v twin, carbs in the center of the v and protruding in to the frame).

Getting them out the first time took a couple of hours and stripping them down, cleaning and reassembly took at least 5 hours and a further 2 hours or so to get them back on. And only to find out they were leaking and wouldn't run. So out they came again but this time, in less than 40 minutes.

Opening them up, recleaning and reassembly was completed in about an hour and getting them on again perhaps another hour.

The bike never really ran right and over the 2 years I had it those darn carbs were off and on again at least 10 timers in a vain hunt to find the problem. Toward the end of my ownership I could, without lie or exaggeration, have them off, inspected and back on in less than 30 minutes.

Despite redoing the carbs, changing coils several times and having the igniter rebuilt twice, that bike never did run right........but it did teach me such a valuable lesson that practice makes perfect or at least repetition makes tasks easier.

While I have learned not to fear the more common CV type carbs, the PDs had me very nervous the first time I looked at them. However with the right manual and guidance from communities like this they really are nothing to fear.

Getting them off and on next time will be a snap, I'm sure.....well maybe not a snap but certainly easier.

Cheers all.
"Slowest beasts are always strongest and Manage to live the longest".
"If it's no Scottish, it's crap".


Return to “Technical Discussion”

Who is online

Users browsing this forum: No registered users and 24 guests