Motorcycle question

Greyd

Platinum Member
Dec 4, 2001
2,119
0
0
Well I finally got my first bike ('81 Honda CM400) and have been driving it around. One thing that I have noticed is that its a pain to start. Most of the time I have to use the choke to keep it running. Once I start driving it might sound like its "choking" once or twice but then everything is fine. Usually I'll just start it and rev it and start driving it. Otherwise, it will start then ddie out pretty quickly. Anyone have any ideas whats wrong?

Thanks
 

The bike is running lean, richen up the idle mixture and/or rebuild the carb.
 

You are welcome, I would also check the fuel filter while you are at it, this can also cause hard starting and lean stumble.
 

Spac3d

Banned
Jul 3, 2001
6,651
1
0
Now don't go drag racing on the freeways at 150mph without a helmet ... bad things happen - I've seen it first hand.
 

Zenmervolt

Elite member
Oct 22, 2000
24,514
34
91
Originally posted by: Roger
You are welcome, I would also check the fuel filter while you are at it, this can also cause hard starting and lean stumble.
I almost doubt that it has a fuel filter, though I could be wrong. I'm pretty sure that my 1982 CB450SC doesn't have a fuel filter.

ZV
 

I almost doubt that it has a fuel filter, though I could be wrong. I'm pretty sure that my 1982 CB450SC doesn't have a fuel filter.

Well that's one of his problems, without a fuel filter, rust and debris will enter the carb which will restrict the small passages and cause the engine to run lean.
 

Greyd

Platinum Member
Dec 4, 2001
2,119
0
0
I have a fuel filter attached to my petcock - I think thats the filter. Its triangular and goes to the carbs
 

Greyd

Platinum Member
Dec 4, 2001
2,119
0
0
Originally posted by: Spac3d
Now don't go drag racing on the freeways at 150mph without a helmet ... bad things happen - I've seen it first hand.

Don't worry. I ride cause I like crusin - I'm not a speed man:D Plus I refuse to go on the freeays till I get a good helmet.
 

Greyd

Platinum Member
Dec 4, 2001
2,119
0
0
How do I know if I have set the misture too lean or too rich? Does the direction of turning the screws have a universal meaning?
 

Monel Funkawitz

Diamond Member
Oct 12, 1999
5,105
0
0
Being an 81, I'd rip off the entire fuel system. steel tanks rust and plug up petcocks over time. Give it a good tuneup too while you are at it @ get the carbs syncronized (If it is a multicylinder)
 

Pliablemoose

Lifer
Oct 11, 1999
25,195
0
56
If you're handy with a wrench & screwdriver, buy a service manual & go through the carbs, & fuel system, like Monel Funkawitz suggested. There also may be an in tank fuel filter attached to the petcock.

I'll bet there's some serious crud in the bottom of your fuel tank.