A General Guide to Trouble Shooting - Starting'
contributed by author: doclockwood...700S rider/revivifyer)
HI, it looks like there's a lot of Nighthawk starting issues (on the list) right now. No doubt, it's mostly from all the winterized bikes coming out of hibernation and from plain old gettin' old, the bikes, I mean. If we have some common tips for starting woes, we could all post 'em to the same page and maybe save someone a little time and work by looking for help (t)here. Many many thanks to all who contribute.
Anyway, I have had my share of starting trouble lately, (I sure have a lot to learn about starters) but if there's one thing I'd check first, it would be:
1) Clean the grounds to frame and engine. Shine 'em up, coat 'em w/ something or other(not biting on THAT one...dielectric grease) and then follow up by cleaning all the contacts in the starting/charging circuit. Test 'em all with an Ω meter (couldn't "resist") and a manual. This includes the kill switch and starter button.
2) Make absolutely sure there's a fully charged battery. It may be necessary to buy a new one every season but that would indicate a charging issue. Even if it's just recently charged, it may lose it's cranking ability after just a few seconds when you hit the start button due to the age/inefficiencies of other components. Take a jump from a car and see if it's appreciably stronger(faster spinning starter) than the bike alone. Cleaner contacts and a "known" strong battery work wonders.
3) Install new plugs and wires. This makes an easier path for the battery juice...new plugs every oil change, even if the bike is running great? I dunno...to each his/her own. But it eliminates a variable if it won't start...new plugs can't hurt.
4) A rusty tank? Bad petcock? Got to be clean. And use fresh gas...my suspicion is that Sta-bil may inhibit restarting in the Spring for folx above the Mason-Dixon line...good stuff to keep the water out of the gas tank, but makes for hard starts initially. Another rookie mistake is to use Stabil in the tank but turn off the bike before it's had a chance to get all the way into the carbs and pistons...I'm certainly guilty of this one.
5) Carbs need to be clean, too. Just from the numerous posts on this topic, it's likely the carbs will gum up or clog sometime during your watch so it has to be considered a chronic problem for Nighthawks, esp. the older models. Lo-speed jets need attention here. Bad idle indicates clogged jets, but it may be electrical, too.
6) The starter should be in good condition. It seems like a no-brainer, but if all the above conditions are favorable, then a bad starter may be the problem. No duh, right?:) There are eBay starters out there and folk who refurbish them, so don't despair.
7) If the starter sounds good/performs well and the bike STILL doesn't start, it MAY be a bad coil, though it's a long shot. My bike was firing on cyls 2 and 4 only so I suspected the 1-4 coil as bad, but it was just a cruddy ground. A meter will confirm coil health.
Lots more tips are in the troubleshooting section in the NH 700S manuals in ignition/starting sections.