Hey!! "old newby" intro and bonehead questions

[OREGONFARMER]

Hi everyone. The weather here finally broke the 70 degree mark today and I need to get on a bike soon or I'm going to go nuts!! I may just have to ride the Honda 50 I bought my 6 year old earlier this week.

I was doing some research on my wife's xs400 and came across this site. I have to say--well done. I like almost all the projects I've looked at and the tech and manual sections are a big help.

The project--

'78 xs400 completely stock. Was running when parked some 20 years ago.

Just trying to get the basics covered first. New battery, oil change, fuel system was dry and relatively clean, new plugs.

Turned key on and got headlight and turn signals. Pulled plugs and ground them to head bolts and kicked it over-----no spark. Checked points, sanded clean---no spark. Pulled cover off of stator/mag and some oil was present. Is this normal? I assumed this area was dry.

Can the coils be tested? I haven't gone through the whole site and the tech manuals yet so bear with me while I learn.

Any help in getting spark would be appreciated.


I've grown up with motorcycles and jet skis my entire life and consider myself to be a gifted mechanic in most areas. We own a large farm about 40 miles SW of Portland in an area better known as "God's Country". I'm 43 and have a great wife and a daughter 6 and a son 11 months. I haven't had a street bike for 15 years and am excited to get back on the road. I'll relate my last day on a street bike story on a later date.


Looking forward to getting to know you guys.

Farmer

 

[cturek]

Yes the coils can be checked for the proper resistance against the values listed in the manual. You didnt mention the carbs. It's a sure thing that you will have to disassemble, clean and renew the rubber parts.

Welcome to the site. Got pics?

 

[OREGONFARMER]

I will be getting to the carbs after I get the ignition working.

Believe it or not--the throttle cable is free, the inside of the carbs have no sludge and very little varnish.

What about the oil inside the stator/mag cover?


I'm terrible with pics but will give it a try soon.

Thanks for the info Cturek.

 

[HoughMade]

Oil inside the stator cover is normal. The manual says to drain the oil before taking it off for this reason.

 

[OREGONFARMER]

Thanks HoughMade.

I'm feeling a get acquainted date with the service manual is on the short list.

 

[bcware]

I was having some trouble with my '78 in the past which lead me to check the resistance on the coils. The resistance I read was very far off from what was listed in the manual, which lead me to believe my coils were bad; it turned out that they were fine.

As a general rule resistance increases with temperature in most materials (semi-conductors are usually the exception). The values in the book are listed at something around room temperature and I took my readings at about 40F. Logically, I should have recorded a lower resistance, but this was not the case; they ended up reading a lot higher than they were supposed to (well outside the range considered normal).

So, my point is that you should be careful if you read funny values from the coils. The manual also mentions that condensers can go bad, that they are not serviceable, and that they can only be diagnosed by a process of elimination (i.e. prove everything else works). I am also pretty sure there is only a single condenser on the '78 and they are cheap.

This is the order of things I would check:

Battery (potential) -> Spark plugs (replace) -> Plug wire (resistance, visual) -> Coils (Resistance) -> Condenser (???) -> Wire harness (visual)

 

[OREGONFARMER]

bc----I've been lurking on this site for a couple of weeks and find your posts to be those of someone who is not a "motorcycle newbie". Thanks for the tip. Maybe you should edit your sub title?

 

[bcware]

I think I am probably a quick learner, but I lack experience and can only comment on the tasks I have completed. I've been wrong about my own bike more times than right--at least initially--, but reading and wrench time helps a lot. Making mistakes is how you learn though Once I tear my bike down to the frame in the coming weeks perhaps I will graduate to a new status.