How do I know how it's suppose to run

[Herr_man]

Hello!
I only went on two rides with my XS400 before winter struck here in Sweden, and to my knowledge it ran well. Now, my previous bike was a modern bike - 08 Suzuki SV650 which of course is a totally different machine. I guess my question is, how do you know how it is suppose to run and feel if you are not used to the bike. Maybe it's running at 100% or maybe 50%.

Thanks

 

[xschris]

These bike only make 34-38hp stock and maybe 40 or so with basic mods. As long as its idling good and not breaking up at all to the red line then I would say its running good.

 

[Charles]

One way is to take a look at your spark plugs. Are they dark and and sooty or are they white, possibly blistering?

Here's a very basic image of what's what. Notice the lean plug has a whiter porcelain where the normal plug's porcelain has a slight tannish look?

Now, depending on your jetting, a lean/rich condition can happen anywhere along your RPM range, so you need to check your plugs after a specific RPM range run.

Here's a good guide for that:
http://www.iwt.com.au/mikunicarb.htm

 

[16VGTIDave]

Keep in mind that gasoline with ethanol (or methanol for that matter) in it will leave the plugs cleaner than the "Perfect" plug pictured above. Especially if there is any water absorbed into the fuel.

 

[Charles]

With that being said, at least here in Jacksonville, Fl, there are stations with ethanol free gas.

 

[Scorpio1963]

If your bike idles and runs smooth,doesnt stall,surge or back fire while riding I would say its running well.If you feel the bike gain power through out each gear shift then your doing good.Also take into consideration from 4th through 6th gear there isnt much of spread between rpms lowering.I would have to say thats one of the largest downfalls of this bike.You can change sprockets to help compensate for this.If i could change anything about this bike it would be the gear box.Changing the gearing and making it a 5 speed would drasticaly improve it.It is what it is though.