Bike was starting, wont start anymore.

[Guest]

I bought my gs450 about a month ago, non running. PO had destroyed the CDI. Got a new regulator and CDI, and pulled off and rebuilt the carbs. Put it all back together and fixed some bad wiring and it fired right up (checked the ignition coils with a multimeter first). The idle was high (choke on) and i didnt run it very long. Couple days later, girlfriend came over and i showed her i had it running. Started it up and same high idle, it ran for about a minute total, and I was turning the choke off slowly. Idle was kind of wild, lowering than revving. Turned it off, saw a little smoke from cylinder (oil and dirt burning off cylinder? Thats what it looked like) Shut it off and left it alone over the weekend. Went to start it for a minute the other day, turns over fine but isnt starting... Dont know whats going on. (I am waiting on new intake boots and airbox boots, they are on the way already) Anyone have any ideas? Maybe running way too lean? Fouled plugs and caps? will pull them when i get the boots in...

[steve murdoch]

Certainly an air leak can contribute to an erratic idle.
The new boots should/might help.
Did you check the intake o-rings? http://www.cycleorings.com/intake.html
Did you use the carb rebuild tutorial from this site?

[Redman]

The eratic idle can be a symptom of some problems.

But when someone says "cranks okay but doesnt start" I usally suspect the battery is either not charged well or battery is going bad. May seem like is cranking okay, but maybe is a bit slow because battery is weak and voltage low enogh that ignition isnt working well.
Try measuring battery voltage while cranking and report here.
Maybe try putting on a charger for a while.

.

[Cipher]

yeah a bike with a fresh battery spins very fast indeed. Maybe all that cranking and not running for a long period has depleted the battery. A charge should be the first check and their is a series of voltage tests to be done on the battery posplayer where are you?

[Steve]

One thing I would suspect is the conversion to CDI, especially if you still use coils.

A CDI ignition system does not use coils. It uses a very large capacitor to store some high-voltage electricity that is generated by some special circuitry, then it is discharged through the spark plugs when triggered.

Your "CDI" module is properly called an "ignitor" by Suzuki. There is nothing fancy inside it, it's just a box of transistors that replaces the function of points. All they do is make and break the current flow through the COILS (which are inductive devices) to create the sparks.

If you have not converted to a CDI system and really only replaced the ignitor, I would agree with the others and say "check your fuel system".

.

[Nessism]

Check for spark in addition to going through the carbs. Make sure there is no rust in the tank too. And adjust the valves of course. Honestly, you need to go through the entire bike to catch up all the maintenance straight away. The Newbie Mistakes thread linked in my signature will help. Lastly, the grounding on the R/R is bad on the 450 which often leads to over charging, and high voltage often kills the ignitor. Best check that straight away...once the bike is up and running.

[Kellencmiller]

To steve, Yes, i used the carb tutorial and bought the gs450 o-ring kit. The new intake o-rings will go on with the intake boots (should be here saturday).
To Redman, battery is dead, have been starting with a battery pack so far, so it has plenty of juice.
To steve, yes, i did mean ignitor.
To Nissism, Any ideas for improving the rectifier grounding? I did get a new one (a ricks motorsport). I think i am going to have to play with the idle air/fuel mixture and the idle speed. The screw came only 1 turn out, which seems low... Anyone know the factory setting so i can adjust from there? Also, how simple is the valve job? I am mechanically inclined, so im not too worried. New plugs and caps will go on with the boots/o-rings/oil change. Also, i have heard horror stories about the cam chain tensioner? Is this something i should be concerned about?
As for the engine not starting anymore, I am an idiot. My engine ground came undone. Reattached and boom, she started again. Guess i shouldn't tease the guy who sold it to me for so cheap (he stated it turned over but didn't start, when i went to look at it, it didn't turn over at all, and i took a bunch off the price. Was just a blown fuse. Only 200 bucks!)

[Kellencmiller]

Just in case anyone asks, i have read the newbie mistakes thread, 3 times through. Trying my best to do them all... One other question, have heard alot about the petcock being a problem, anyone know how to check if mine is an issue? Have also seen threads saying the rebuild kits arent worth it, is buying a new one the only way to go? If so, suggestions for places and models to purchase?

[tom203]

Petcock, best to just replace it and move on to other fun, but if you want to check yours...

Assuming it's still the stock petcock...... This has 3 positions: "pr ", "on " ,"res" : in "on" and a "res" ,fuel should only flow when engine is running (engine vacuum is applied to the petcock letting fuel flow). The "pr" spot lets fuel flow at all times - this is used after bike has sat idle and fuel has evaporated from carbs this spot quickly refills carb. But you don't want to leave it in " pr" when bike is not running,as carbs will likely overfill - if this happens, fuel will run into crankcase diluting the oil.

Try this... remove both lines from petcock: get some clear vinyl tubing that fits snugly on petcock vacuum fitting. In "on" and "res" fuel,show flow when you suck on this tubing- otherwise it should not. Any signs of fuel in the tubing means the petcock diaphragm is likely leaking.maybe just when bike is running but maybe at alltimes.

If you need one, I bought one from this ebay guy years ago..
(there is also a version with less reserve )

http://www.georgefixs.com/brand-new-suzuki-gs300-gs450-gs550-gs650-gs750-gs850-gs1000-gs1100-petcock/