Jump to content
zenith99

520h won't start

Recommended Posts

zenith99

Hi,

I've been looking at the forum for help with my starting issue but decided just to post because I'm stumped. We bought this tractor a 90, I think, 520h this summer, it started and ran great. It sat then till a few weeks ago, put a new battery in and it started although ran a bit rough. Next time I tried to start it, it was no go, would try to fire and occassionaly backfire through the carb. So here's what I've done. New plugs and they fire, checked grounded to engine and with a test light. Checked the ignition trigger, it tests ok. The coil tests ok for resistance but when I do the test for voltage I only get 10.5, can that be the problem? I know there's spark but the tractor will not fire even spraying carb cleaner or ether directly in the carb. As I say, I'm stumped. Any suggestions? I need to get this up and running, it has a snowblower and was going to be the main machine this winter.

Thanks for any help,

Brad in snowy Duluth MN

Share this post


Link to post
Share on other sites
 
WH nut

Welcome to the club, Since it did fire then died,and you seem to have spark I would try pulling one plug out and lay the plug grounded to the motor and crank it. Watch for spark and see if she fires. It doesn't take much to flood and since you said it did start and ran rough Im think you have crude in the Carb.

Share this post


Link to post
Share on other sites
 
zenith99

I did check for spark and it's got it, that's why I don't understand why it won't fire by spraying directly in the carb. I did take the top of the carb off and spray everything with carb cleaner to no effect. The carb is clean inside.

Share this post


Link to post
Share on other sites
 
ericj

the best advice i can give you is to down load the onan service manual which i believe is on here for down load and go through it step by step it will tell what to do and how to do it. did you try to run a jumper wire from the battery to the + side of the coil and see if it will fire ? the guide also tells you to try this step.

 

 

 

 

eric j

Share this post


Link to post
Share on other sites
 
KC9KAS

:WRS:  Good advise about dowloading the manual. Good luck getting your GT going.

Share this post


Link to post
Share on other sites
 
WH nut

Watch the spark and try and start it. I have seen them start with one plug when they are flooded. Let her crank a bit and see if she will fart. Also try spaying some carb cleaner in the carb if you doesn't pop after 10 or 15 seconds.

Share this post


Link to post
Share on other sites
 
Red-Bovine

Since it backfired through the carb, my guess it puked an intake valve seat. Very common in 520s. Do a compression test. You should get about 110-120 on a good engine.

 

Red

Share this post


Link to post
Share on other sites
 
zenith99

OK, so I did a compression test and got 115 on both cylinders, I guess that rules out a valve problem. I've gone throught the checks in the manual and everything is ok except where it says to test the the coil for 12 volts I get 10.5 volts. Does this mean the coil is bad? Kinda frustrated here.

Brad

Share this post


Link to post
Share on other sites
 
ericj

check the 9 pin connector these are  known  to be a problem and could loose voltage though them

 

 

 

 

eric j

Share this post


Link to post
Share on other sites
 
motox25

It's probably not your coil, back firing at the carb sounds like the timing is off. Mine did this exact thing when I failed to torque down the flywheel completely and it broke the flywheel key which throws the timing off. If you can rule out a fuel issue id pull the flywheel and check it.

Edited by motox25

Share this post


Link to post
Share on other sites
 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...