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Discussion Starter #1
Cant figure this one out... Put new bars on the cb and when I got it all back together I've lost the (r) when sitting on the bike cylinder. Getting gas, took float off the carb and float is working. Getting spark, and there is definetly compression. I havent been able to get a volt meter to the coil or been able to accurately measure the compression (I'm out of town right now). The right cylinder seems to fire for about 2 revelutions when the plug is pulled, cleaned and put back in, and then drops off again. I'm thinking ignition related and my buddy seems to think gas related. Any ideas, I'm sitting in a hotel room right now so the only thing I can do is write about it...
 

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seems intermittent electrical to me...you have spark but maybe not all the time.see if its grounding out some where it shouldnt be goo to do when its dark or very low lighting look from coil to engine.look for grounds that may have worked loose.If its points be sure they hav a good gap a match book will do if away from a feeler guage.does seem like gas but hey check the filter out. good luck

PS maybe something got wet sound like something simple to me but you neeed to look carefully .
Also you mentioned change handle bars look where on/run/off switch maybe some thing is grounded..that should knock out the whole bike not just on cylinder but you never know with old bikes what someone previously has done.

Im so far behind ,that I think Im in first.

Edited by - LiLBull on Aug 02 2007 06:30:43 AM

Edited by - LiLBull on Aug 02 2007 06:33:22 AM
 

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Discussion Starter #4
thanks for the tips... I'm thinking electrical too. Oh and the bike is a 70 cb450
 

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I am not sure about the cb450 as to whether it is a dual point bike or not but if it is then you should check the points firing the right cylinder.
 

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Yep, it's dual point firing every two revolutions (no waste spark).

Your description positively screams electrical issue - assuming it ran normally before you played with the bars, the only other thing you've got there is the throttle cable (and there's a possibility there - we'll get to that).

I'd open the points cover and manually open the point for that side (with a rubber-handled screwdriver). Every time you break contact the plug should spark. This is best done at night. Visually verify that the PLUG is sparking, not just the points (which shouldn't spark much anyway if your condenser is working). All working? Next thing.

If you're going to do this, remember to do BOTH STEPS. 1) Swap the blue and yellow wires from the points to the coils. 2) Plug the right coil wire into the left spark plug/cylinder and the left wire into the right cylinder. Try starting your bike. What you've done there is swapped the coils electrically. If it still only runs on the left, you've verified that the coil and wires are not the culprit. Swap back.

Now, a fun fact: 450s are prone to losing the right side more than the left. The reason is that the pistons don't move in tandem - when one is up, the other is down. Now think about what that means - there's physically no way to set the firing cycle 360' apart. SO, the left fires first, and then the right very soon after, the result being that if the left side is in even a slightly better state of tune, or is set to a higher level of throttle, the right gets dragged and shuts down.

This is a long way of saying, pull the air filters and peer down the carb throats to see if the left side is being held open by the throttle cable. Check the 2-1 connection to see that the left side hasn't popped out of the connector. That would hold the left at a higher level of throttle, effectively killing the right.

If that doesn't work, I'd try this: remove the air filters, open the throttle and spray starter fluid or carb cleaner down the throat of each carb for a couple of seconds, and then immediately try to start it. If it runs for a few seconds, that strongly suggests a fuel/carb issue. If no, you've got timing and compression left. Or you could toss it on a truck and ship it to Madison. I accept birthday presents year round.

A
 

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Discussion Starter #7
That sounds like really good advice. I cant wait to get home and give that a shot. If it doesnt work, I'll get it on a truck to ya ASAP! hahahaha!!! I'll let you know what I figure out.
 

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ah yet another cb450 twin joins the fold.I love the twins .Harleys juststayed there with the twins big thumping jugs,twins just work nicely most bikes that use a twin design seem to always have cult bikes in their future.
I have a few four cylinder bikes but seem so over down and awkward compared to a nice twin.


You need to post a pic of your bike as payment...we like pics

Im so far behind ,that I think Im in first.
 

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Good to hear it. Great looking bike, btw. If ever you feel like ditching the clubmans, you can get clip ons from mikesxs.com for like $45.

A
 

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Champs are better quality,but if you went away from the clubmans you have to take off the headlamp ears and blaa blaa blaa .ENJOY YOUR BIKE,the way it is.
Glad you found and reported the problem .

Im so far behind ,that I think Im in first.
 

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Discussion Starter #14
I'm digging the clubmans. I think they look cool, and since I spent about 4 hours drilling them out and running all the wires through them I think I'll keep em for a while. Also, I have a hard, uncomfortable sportbike with clipons and I kinda like not feeling like I've been sitting on a torture rack when I get done riding her!

Thanks for all the advice guys, I really appreciate it!
 
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