Yesterday's Tractor Co.
Shop Now View Cart
   Allis Chalmers Case Farmall IH Ford 9N,2N,8N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   Traditional YT Forum ViewClassic View   RegisterRegister 
 ProfileProfile    Log inLog in 

HELP - 6x4 Backfiring and No Start


 
Post new topic    
View previous topic :: View next topic  
Author Message
afavia
New User


Joined: 12 Jan 2021
Posts: 8


Report to Moderator

PostPosted: Tue Jan 12, 2021 6:43 am    Post subject: HELP - 6x4 Backfiring and No Start Reply to specific post Reply with quote

I purchased a 1998 JD 6x4 with Kawasaki FD620D Liquid Cooled engine that will not start and only backfires through the carb when starting attempt.

I have completed the following:
1. Compression tests show 175/180
2. Flywheel rotated to TDC on each cylinder and valves adjusted to 0.010
2a. I made sure of TDC with a screwdriver in the spark hole.
3. All push rods and rockers checked and confirmed ok.
4. Valves and rockers operate as should with starter motor, cam gear must be ok.
5. Spraying starting fluid in carb or directly in intake only can achieve a backfire through carb / intake
6. Spark / Fire tested and successful at each plug. Verified against block and with spark plug tool.
7. Fuel verified and confirmed at carb. Electric Fuel Pump.

Next Steps I am planning:
1. I ordered new spark plugs (NGK BMR2A)
2. I ordered a new carb
3. I will clean out the spark arrestor and muffler.
4. Planning on pulling the flywheel and checking woodriff key.

I am honestly stumped on this. I have good air, fuel and spark. I have tried with choke, air filter removed, carb covered with hand, spray, etc. Also, the oil is overfull and thin but clean and correctly colored. Possible fuel in gas tank from starting attempt too many times without firing?

Any help would be appreciated.
 
Back to top
View user's profile
David G
Tractor Guru


Joined: 11 Jan 2008
Posts: 29337


Report to Moderator

PostPosted: Tue Jan 12, 2021 7:18 am    Post subject: Re: HELP - 6x4 Backfiring and No Start Reply to specific post Reply with quote

Your timing is off, remember there are two TDC's.

When did it run last?
 
Back to top
View user's profile
afavia
New User


Joined: 12 Jan 2021
Posts: 8


Report to Moderator

PostPosted: Tue Jan 12, 2021 7:38 am    Post subject: Re: HELP - 6x4 Backfiring and No Start Reply to specific post Reply with quote

I am starting to think the timing is off as well. However I can believe the cam gear has any problems as the valves are operating as intended. Yes, I rotated to TDC 2x and set gaps on valves each time. What else could be throwing the timing off? I checked TDC on the flywheel and confirmed with a screwdriver in the plug hole to verify that the flywheel was not off.
 
Back to top
View user's profile
David G
Tractor Guru


Joined: 11 Jan 2008
Posts: 29337


Report to Moderator

PostPosted: Tue Jan 12, 2021 7:56 am    Post subject: Re: HELP - 6x4 Backfiring and No Start Reply to specific post Reply with quote

I would "assume" that valve timing is good based on your compression numbers. I would leave the fuel side alone for now. If multiple cylinder are you sure plug wires are not crossed?
 
Back to top
View user's profile
Dan in Ohio
Tractor Expert


Joined: 27 Apr 2008
Posts: 1918


Report to Moderator

PostPosted: Tue Jan 12, 2021 8:56 am    Post subject: Re: HELP - 6x4 Backfiring and No Start Reply to specific post Reply with quote

Your gator started getting the steel cam gear starting with this engine and serial number in Feb of 1998, FD620D-ES11 – Beginning serial 152490 – John Deere Model 6×4 Gator, if you still have the plastic cam gear that is where I am putting my money.
 
Back to top
View user's profile
jd man wis
Long Time User


Joined: 27 Apr 2014
Posts: 667


Report to Moderator

PostPosted: Tue Jan 12, 2021 12:59 pm    Post subject: Re: HELP - 6x4 Backfiring and No Start Reply to specific post Reply with quote

I also would say that the key in the flywheel and crank are sheared and throwed the timing off that where I would check.
 
Back to top
View user's profile
gbs
Long Time User


Joined: 30 Oct 2010
Posts: 1373


Report to Moderator

PostPosted: Tue Jan 12, 2021 5:11 pm    Post subject: Re: HELP - 6x4 Backfiring and No Start Reply to specific post Reply with quote

neighbor had the same problem with a 14 hp briggs, he said when he was trying to start it his mother who lives next door called to find out what all the shooting was about, found out it had sheared the flywheel key was his problem, unlike the point type ignition an electronic ignition will still fire with the key sheared.
 
Back to top
View user's profile
afavia
New User


Joined: 12 Jan 2021
Posts: 8


Report to Moderator

PostPosted: Wed Jan 13, 2021 12:05 pm    Post subject: Re: HELP - 6x4 Backfiring and No Start Reply to specific post Reply with quote

I went to oreilys and rented two (2) jaw pullers, however the 1st one (5-ton) was too small for the flywheel, and the 2nd one (7-ton), the metal was too think to fit behind the flywheel and the block. Anyone have a trick to get the flywheel off without using a hammer and pry bar?
 
Back to top
View user's profile
K Effective
Tractor Expert


Joined: 04 Feb 2015
Posts: 2189
Location: Below the pinky finger of the Mitten

Report to Moderator

PostPosted: Wed Jan 13, 2021 12:23 pm    Post subject: Re: HELP - 6x4 Backfiring and No Start Reply to specific post Reply with quote

Flywheel is just taper fit to the shaft. A pry bar can take up the small amount of thrust in the crankshaft, then tap on the crank end with a brass hammer, or I have seen an air hammer used. The flywheel should pop right off, as long as there is just a little space for the crank to move away from the seat. Try to get the pry force as close to the center as possible.

If you can clean the end of the crank really well, you might be able to see the keyway cut in it and compare to the keyway in the flywheel, but not always.
 
Back to top
View user's profile
afavia
New User


Joined: 12 Jan 2021
Posts: 8


Report to Moderator

PostPosted: Mon Jan 18, 2021 7:14 am    Post subject: Re: HELP - 6x4 Backfiring and No Start Reply to specific post Reply with quote

I was able to remove the flywheel with a harmonic puller. To my surprise the woodriff key is actually a part of the crank and not seperate? I cleaned everything up and took the opp. to replace the plugs and again re-seal the carb with new gaskets and gasket sealer. It fired up! I have no idea what I did to correct this issue, as nothing else was really improved or changed?
 
Back to top
View user's profile
:   
Post new topic    Yesterday's Tractors Forum Index -> John Deere All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  

TRACTOR PARTS TRACTOR MANUALS
We sell tractor parts!  We have the parts you need to repair your tractor - the right parts. Our low prices and years of research make us your best choice when you need parts. Shop Online Today. [ About Us ]

YT Home  |  Forums

Modern View Forum powered by phpBB © 2001, 2005 phpBB Group

All Rights Reserved. Reproduction of any part of this website, including design and content, without written permission is strictly prohibited. Trade Marks and Trade Names contained and used in this Website are those of others, and are used in this Website in a descriptive sense to refer to the products of others. Use of this Web site constitutes acceptance of our User Agreement and Privacy Policy

TRADEMARK DISCLAIMER: Tradenames and Trademarks referred to within Yesterday's Tractor Co. products and within the Yesterday's Tractor Co. websites are the property of their respective trademark holders. None of these trademark holders are affiliated with Yesterday's Tractor Co., our products, or our website nor are we sponsored by them. John Deere and its logos are the registered trademarks of the John Deere Corporation. Agco, Agco Allis, White, Massey Ferguson and their logos are the registered trademarks of AGCO Corporation. Case, Case-IH, Farmall, International Harvester, New Holland and their logos are registered trademarks of CNH Global N.V.

Yesterday's Tractors - Antique Tractor Headquarters