Cafe Racer Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
55 Posts
Discussion Starter #1
Well I got my bike running after sitting for a while. (honda cb450 '74) It will start up with one kick, but only one side is going. I checked the fuel line running to the carb, cleaned the inside of the carb and tried some spray in the send house. But it is still hesitant to fire correctly. After a little bit it will start to back fire, sometimes it catches and both cylinders are running just fine.

Any suggestions on what i should try? or not try? It ran fine when i bought and parked it. thanks in advance to anyone that responds. (you guys are way too smart for your own good, so this should be an easier one).

-david
 

·
Registered
Joined
·
7,125 Posts
The send house. I like that.

How long was it sitting for? Over the winter?
 

·
Registered
Joined
·
55 Posts
Discussion Starter #3
Well i dont know the correct terms, i just gave it a simple name that would make sense, ha.

The bike set from about october till now. so through winter. It was covered outside, and i live in texas... so it never frooze or anything like that.
 

·
Premium Member
Joined
·
11,267 Posts
Hate to state the obvious...but have you checked for good spark on the side that isn't firing?

Also...look in there and make sure the slide isn't sticking and the choke is working in unison with the other side.

Check the plug......wet or dry?

JohnnyB
 

·
Registered
Joined
·
55 Posts
Discussion Starter #5
Yeah i replaced the plugs, sprayed some carb cleaner in the carbs. somtimes it will kick in, but it will backfire. the pipe is cold. the old spark plugs were still in good shape, but i put new ones in just to be on the safe side.
 

·
Registered
Joined
·
7,125 Posts
He saaid . .. Did you check for spark on that side, not did you replace the plugs.

Do you know how to check for spark at the plug??

s
 

·
Premium Member
Joined
·
11,267 Posts
Pulling the plug and checking will help tell you whats going on...wet probably means a spark problem....dry means a fuel starvation problem.

If you have good spark and the plug is wet then you have a flooding problem...float has a hole in it, adjusted wrong...choke on.

If you have good spark and the plug is dry...then you have a clogged jet, crap in the needle, clogged filter etc.

Like Scott said...check for a good spark...that's always task one.
JohnnyB
 

·
Registered
Joined
·
55 Posts
Discussion Starter #8
Got it. so i pull the plug while the engine is running? see if there is a spark or any change in the idle. (sorry guys, i know very little about these things).

Whats the best way to check for a spark?

ps. thanks for helping me even though i call things send tubes and whatnot


-david
 

·
Registered
Joined
·
7,125 Posts
There are several ways to do it. I am assuming your kick start is still there.
1. Pull both plug wires off the plugs.
2. take out both plugs.
3. put both plugs back into the plug wire boots, make sure they are well seated. Be careful with the connection between the wire and the boot, they are fragile on these bikes. If it seems the wire is loose going into the boot, that may be the problem. Remember . . . THESE ARE FRAGILE
4. Turn the switch to "on", As you would normally start the engine
5. Lay each plug on the little deck where the plug hole is. If you have buddy there, this is best done in a darkened garage and with him holding the plug onto the deck. the outside of the metal part of the plug needs to be GROUNDED to a part of the bike. If you are outside in the bright sun, you may not see the spark, though if everything is operating correctly, you should be able to see it. But if you've never done this, a darker area is best.
6. Now, there are several ways to do this, so let's start with the "easiest" Hit the start button. (I am going to asume as you have a 74 that you have the e-start) At the tip of each plug you should see a strong bluish white spark. About one every second or so. If you don't have the starter, use the kick starter to turn the engine over. Check both sides and make sure if you have sparks coming at the tips. IF NOT, we move on to electrics. If you DO HAVE SPARKS we move on to fuel. (Again, make sure the bike is turned "on" when you are doing this!!)

s
 

·
Registered
Joined
·
347 Posts
in addition to what imslow said, i would reccomend to never use the honda kill switch to turn the bike on or off except in an emergency. these switches are 30+ years old and were prone to failure when they were new.
 

·
Premium Member
Joined
·
11,267 Posts
My RC51 has a neat feature.....if you hit the kill switch by accident while you are stopped somewhere....then try to start the bike...all the lights come on, dash works, fuel pump comes on...bike turns over when you hit the starter.....won't start.

I know more than one guy that called the truck for a ride home only to later discover he had accidently hit the kill switch.

I was about five minutes from calling when I found I had hit mine :)
JohnnyB
 

·
Registered
Joined
·
138 Posts
ok Duh now for the newbie dummy question.....
So you just turn the bike off with the key instead of using the kill switch?
I always use the kill switch (that is when I can get my bike running ha ha)
maybe thats one of my growing probs with my bike....
 
1 - 12 of 12 Posts
Top