From: cdw2t@dayhoff.med.Virginia.EDU (Clifford David Weston)
Newsgroups: rec.motorcycles
Subject: Re: fuel problems on a CM400T -- need HELP!
Date: 3 Sep 92 20:52:01 GMT
Distribution: na
Organization: University of Virginia

In article <1992Sep3.152313.22059@ohrd.uucp> ohrd!jlevine@cs.toronto.edu (Jody Levine) writes:

>In article <1992Sep2.013405.18531@murdoch.acc.Virginia.EDU> cdw2t@dayhoff.med.Virginia.EDU (Clifford David Weston) writes:

>>my buddy in pittsburgh has an old cm400t with a fuel problem.  after having
>>a retired mechanic tune it up/get it roadworthy after two years in storage
>>(included rebuilding/synching the carbs 'by ear'), it presents the following
>>symptoms:
>>
>>choke on:  idles high, starts out fine from rest, ok at speed
>>
>>choke off: idles fine, bogs badly when pulling out, tough to get the speed
>>           over 40mph or so.

>Easy things first. Are you sure you know which setting is on and which is
>off? (It is not always marked) It sounds like you've got it right, but
>you never know.

yes

>The symptoms sound like your bike is cold. I hope you're letting it warm 
>up (no skimping!) before turning the choke off. This may take quite a few 
>minutes, depending on the outside temperature. My RZ runs just like this 
>when it's cold, only worse. When it warms up, it's fine with the choke
>off, and runs poorly and refuses to idle with the choke on.

after 30 minutes, it still does this

>If you can get the bike to run hard and fast consistently then you don't have 
>a fuel flow problem between the tank and the carbs. If it won't run with the 
>choke off but runs with it on, then your mixture must be too lean. Other
>things which may pass for bad mixture are (off the top of my head) poor 
>carb synchronization, or (one should never leave ignition out of fuel- 
>related problems) your timing may be off or your spark plugs may be toast.

bike will *not* run hard nor fast, but rather like shit unless the choke is
wide-open.  he can't break 40 or so in any case, and the thing almost dies
pulling away from a stop unless generous choke is given.  he's had this bike
several years now, but stored it (improperly) for the last two.  i'm certain
the oil wasn't changed, but the carbs were cleaned/rebuilt.

>>... if more details are needed, i'll
>
>Yes, please. Does it always run this way or is it intermittent or temperature
>dependent, throttle position dependent, etc.

always this way (since coming out of storage)

>Air jet, maybe (don't know if your carbs are the same as mine)? Yes, if it's 
>open too far this may account for your lean mixture. Get a service manual 
>and follow the adjustment procedure....

jason has the mechanical aptitude of a 'stereotypical woman' and the deft
adjustment touch of an overmedicated spastic

>or take the bike to a dealer for proper
>adjustment of all the little screws on the side of the carbs. It sounds
>like you guys did it using the looks-about-right approach instead of finding
>out what would make it run well. Get it adjusted right, and if it doesn't
>work then, come back and we'll start looking for bad parts.

*we* didn't do it, a retired bike mechanic did it.  which counts for nothing,
apparently.  thanks for the suggestions, though.


cliff weston
dod# 0598

i love the fiamms.
the fiamms are my friends.
Newsgroups: rec.motorcycles