It's not unusual for the start procedure to be as you describe - my 500 does exactly the same thing and a big part of it depends on what position the crankshaft stopped in when shut off - the auto decompressor only works on the first rotation of the camshaft - if the speed of the camshaft is fast enough to retract the decompressor as it comes up on compression the first time, the piston can stop against the compression - letting off the starter button, the compression pushes the piston backwards a little resetting the decompressor - the next time you push the starter button, it lets the compression out and gets up to full cranking speed so the next time it comes up on compression it goes over TDC like nothing and continues to crank.

Depending on the model and specific wiring, there is a switch in the throttle and using the throttle can activate the switch stopping the attempt to start.

Depending on the carb, it may just need the enrichener orifice in the float bowl enlarged slightly or the valves may be needing adjustment - the colder the engine, the lower the compression and the weaker the battery - warm the battery so it can discharge faster and the starting may be easier.

 

Thank for the reply.

I don't believe mine has that sensor because if I touch the throttle in any position it will still try to engage the starter but with the throttle in any position instead of 0 It just doesn't seem to have the power to turn it over. oh and this all happens during the summer as well as now that it is cold. I normally keep a battery tender on it during the winter to keep the battery at its peak.

When you say enrichener, are you meaning the air/fuel mixture, or is that something else.

 

Opening the throttle raises the compression and keeping the battery on a tender can damage it - put a meter on the battery terminals and check the voltage drop when cranking the engine - my guess it the voltage is falling below 10.5 volts.

 

Sorry, I meant battery maintainer, it only charges when it is needed. I had the feeling the throttle would increase compression but I was not sure.
I will check the voltage drop when I get a chance.
Thanks

 

I didn't have my tester, so I couldn't check on Amp draw but the link below is what I have for a Maintainer.

Schumacher 1.5A 6/12V Automatic Battery Maintainer - SC1355 | Blain's Farm & Fleet

Get your Schumacher 1.5A 6/12V Automatic Battery Maintainer - SC1355 at Blain's Farm & Fleet. Buy online, choose delivery or in-store pickup. Great prices on Battery Chargers.

www.farmandfleet.com

I noticed one thing when doing some adjusting to the thumb throttle cable. If I adjust it up by the thumb, to loosen it to give it free play before it engages, the ATV will crank but will not fire at all until I touch the throttle very slightly to snug the cable. I turned the idle way up just to see if that had any difference and it did not. It just acts like there is no spark and will just turn over. Is there some sort of safety switch that causes that? It just seems odd that if it is loosed up so that there no absolutely not throttle being on it will not even attempt to fire.

I accidently ran down the battery the other day when I was figuring this out and once I put a charger on at 10 or more amps the thing turns over great, so I think I need a more powerful battery. Any suggestions?

 

OK - I guess I need to know what model and year machine we are talking about - there are different procedures for some models - some need the safety switch open and others need the safety switch closed

Give me the VIN and I'll see what model you have and check the service manual for your's

Also, that charger could damage your battery - 1.5 amps is a bit HOT - since the literature does not specify what the float rate is, I definitely would have it on an outlet timer and not turn it on more than a couple of hours a day.

 

OK - I guess I need to know what model and year machine we are talking about - there are different procedures for some models - some need the safety switch open and others need the safety switch closed

Give me the VIN and I'll see what model you have and check the service manual for your's

Sorry for the delay, got busy the past couple weeks
Vin
4XACD50A2XC095720

 

I did some investigation and found this information on that 'maintainer'

• Charging Amps @ Voltage1.5A @ 12V, 1.5A @ 6V
• Maintaining Amps @ Voltage1.5A @ 12V, 1.5A @ 6V

It's charging and maintaining amperage is listed as the same - 0.1A is a float charge - the maintenance charge equals the recovery charge - no wonder it's so cheap, it will burn up the battery.

Spend $60 and get a good Battery Tender or Yuasa brand 750, 850 milliamp or 1.5 amp maintainer and still use an outlet timer.

 

OK - here's what the VIN tells me

Model Name - MAGNUM 500
Model Year - 1999
Model Number - A99CD50AA
Purchase Date - 8/18/1999
VIN - 4XACD50A2XC095720
Engine Serial Number - 9907328

Here's how to adjust the throttle cable - based on your description of the problem, I will guess that the throttle switch is defective and it takes some throttle movement to make the switch operate as designed. The switch is not replaceable - you have to replace the entire throttle assembly to replace the switch. For testing, unplug the safety switch wires and see if that resolves the problem. This is not a fix and the defective part should be replaced. If this does not resolve the problem, please let me know so I may investigate the situation more.