Topic: 1982 CM450C info needed

[KCs76Cafe]

I finally started tinkering on the CM450 I picked up for cheap. rebuilt the front caliper last night but it still needs a master cylinder......cant get any pressure in the line to bleed. Will probally pick up one like I put on my 76 750.

The PO has taken the center section...backpressure chamber/crossover?...out of the exhaust and filled in the space with a straight pipe. The bike cranks and idles fine but when I give it gas the right cylinder...1 or 2?....spits,sputters and backfires. Is the missing chamber causing this or should I look at rebuilding/cleaning the carbs? I figured it might be a backpressure problem with the chamber missing.

Anybody?

[KB02]

Carbs.

Once you get the air box off, pull the thottle wide open ansd take peek into the back of the carbs to see if the needle has gone up or not. A buddy of mine has a CB400T (The older brother to your CM450) that had put a rebuild kit in his carbs, but the retaining ring on the needle kept coming off so the needle would not raise with the throttle. Caused all kinds of issues.

I would doubt it is the exhaust, but I wouldn't rule it out, either.

[crazypj]

The crossover is to improve low/mid range, should run OK without them
 Bike has 3 jet piston type CV carbs, rubber plugs over pilot jet? (I forget, think it feeds from primary main jet )
They need a really good cleaning (and when your done, do them again to make sure )
 Pilot screw has, spring, steel washer, rubber washer, and check the tip hasn't snapped off in carb body. Happens when people tighten them too far-lightly seated doesn't mean crank it down until it wont go any further.
Main change from 400 is the 5mm bore increase.
PJ

[aptech77]

Put the expantion chamber back in.

[Slapguts]

Carb trouble. I put a MAC 2-1 on my bike, a 78 cb400t with a cm450 engine and it runs fine. If the exhaust was the problem, both sides would be sputtering.

[HITMAN]

I had a 78 CB400T (hawk) that had carb probs early on, I agree with the circlip on the needle.  I squeezed them closed just before putting them on, major pro on mine though was the slides (keiHin) had laquered with old gas and was a little sticky.  Just watch where the spring goes when you take the top off (doh).

[KCs76Cafe]

Thanks for all the info guys........as soon as it warms up a little Im gonna get this thing on the road.


Slapguts......thats an awesome looking ride you got going. What kind of tank is that? Stock CB400T?  Im just hoping I can get that look with my Custom......its got that Cruiser look to it....and it looks to be "built in"...with all the swoop in the frame/seat area.  Are the frames different between the 2 bikes.....CB and CM?

Still looking for a left side cover...........

[KCs76Cafe]

Still looking for a left side cover...........

Anybody know if the CM400 side covers will fit my 450? I have been looking on ebay forever for 450 sidecovers.......now these 400 covers are on there........

This one the part number is one digit off..... 83740-447A  and my right side cover is 83640-447A ....
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=020&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=300078099548&rd=1,1

There are 2 more sets of 400 covers as well.....
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=220079428922&ssPageName=STRK:MEWA:IT&ih=012
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=220079428934&ssPageName=STRK:MEWA:IT&ih=012

[Slapguts]

If I remember to pick up some batteries for the camera, I'll post some pics of my CB400T with the side cover off to see if the holes line up.