Welcome! Please use the navigational links to explore our website.
PartsASAP LogoCompany Logo Auction Link (800) 853-2651

Shop Now

   Allis Chalmers Case Farmall IH Ford 8N,9N,2N Ford
   Ferguson John Deere Massey Ferguson Minn. Moline Oliver

Tractor Talk Discussion Forum

can't figure what the problem with this motor is i

Welcome Guest, Log in or Register
Author 
lawnmowerkid

06-07-2005 20:44:39




Report to Moderator

Recently I found a "high performance I/c 16.5 hp" Briggs & Stratton motor in the garbage. My problem is it won't start. it started once, has tons of compression, no oil leaks, fresh gas, and a lot of spark. All it does is flood out and backfire. It backfires out of the carb. I have all the tunings correct (I thought) but I can't get it to run. how can I set the tunings? I've removed the flywheel and sanded all the rust off, and replaced it. I'm looking to put it on my tractor I just broke my valve rods on my platinum series 15.5 hp. I'm pretty good with motors for a kid and I know this because I've brought two "dead" mowers (found in the garbage) and made one do 43mph and one do 38 mph. Another question I have is if anybody has ever lifted a lawnmower I'd like to know how?

thanks for any help that can be given, mike

[Log in to Reply]   [No Email]
batemanlb

06-08-2005 20:52:41




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-07-2005 20:44:39  
Everyone else put in 2 cents, here's my penny.

Backfiring and hard starting generally go to timing or fuel flow. Fairly easy to chek timing as many mentioned. Pull flywheel and if the sheer pin is marked, get a new one. I believe in this case though, a carburator kit will do wonders. Needle valve off just a little is enough.



[Log in to Reply]  [No Email]
lawnmowerkid

06-09-2005 13:40:16




Report to Moderator
 Re: can't figure what the problem with this motor in reply to batemanlb, 06-08-2005 20:52:41  
for some reason its dumping tons of fule into the motor even when the adjustments are screwed all the way in. its till backfireing out of the carb and not out of the exhaust. i opened the motor up last nite and noticed the valve rod wasnt in the right place so i fixed that. both valves move up and down. i fixed it and still the same. what chemical can i use to clean the carb completly out.

thanks for the tips,
mike

[Log in to Reply]  [No Email]
bateman

06-12-2005 20:05:14




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-09-2005 13:40:16  
I use chemtool, any brand will work. It sounds like your needle valve is the problem. Where it seats" to cut off fuel must be gummed up, or worn. I have had the tank run dry because the needle couldn't shut gas off.

Try this, put a shutoff between the tank and fuel bowl. Shut gas off, let everything dry out. Then let just a trikle of gas through the cutoff. This may allow you to get it started.
Good luck.

[Log in to Reply]  [No Email]
lawnmowerkid

06-08-2005 16:15:39




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-07-2005 20:44:39  
well I went to the lawnmower store bought a new float needle and asked about the solenoid and the recommended removing it and replacing it with a normal float screw. I also bought a flywheel key. but it keeps breaking them in half. I don't know why. also something I noticed the flywheel has a little wobble to it.does this mean my crankshaft is bent? I tried playing with the carb adjustments and all I can get is a blue flame out of the exhaust

thanks for all the help,
mike

[Log in to Reply]  [No Email]
pperry

06-08-2005 19:21:35




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-08-2005 16:15:39  
i have had this promblom before with the key shearing as soon as it starts. i found that the flywheel &,or the crank key groove gets a loose fit over the years. i went to my local napa store and picked up some keyway stock and i make my own. some you have to grind down and make it a snug fit



[Log in to Reply]  [No Email]
lgc

06-08-2005 13:40:08




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-07-2005 20:44:39  
I assume you have replaced the oil if it is diluted with gas. Sometimes puting a shut of switch on the gas line works if gas is leaking past the float valve. I have seen also a couple of mowers that just wouldn"t run right if the oil was diluted with gas.



[Log in to Reply]  [No Email]
Joe Bloggs

06-08-2005 08:53:20




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-07-2005 20:44:39  
every one is going for tuning. I say its done a valve seat. I have found many ride on mowers with this same problem



[Log in to Reply]  [No Email]
Delbert

06-08-2005 05:38:12




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-07-2005 20:44:39  
Try a new key in flywheel, and needle valve and seat in carb. As others has said just a tiny bit on the flywheel can throw the timing off. And also check the slot in the flywheel and crank to make sure there is no play in them. I,m sure it is quit simple to fix.



[Log in to Reply]  [No Email]
dbwillia

06-08-2005 04:42:18




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-07-2005 20:44:39  
We have an 18 HP Briggs and Stratton engine that was backfiring through the carburetor. It took a lot of coaxing to get it to run and then would run poorly and only for a very brief time. We replaced the coil and it runs super. Possibly you have the same problem.



[Log in to Reply]  [No Email]
3010 Ken

06-08-2005 04:27:26




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-07-2005 20:44:39  
Morning:check the flywheel key.



[Log in to Reply]  [No Email]
fuzzyw

06-08-2005 03:48:40




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-07-2005 20:44:39  
remove the flywheel and replace the key. if the key even has a mark in it that means it has changed timeing. key cost about fifty cents. think this will solve your problem. if not get back to me. wally



[Log in to Reply]  [No Email]
Davis In SC

06-07-2005 21:14:40




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-07-2005 20:44:39  
Even if you have a new plug, try putting in a new one. Cheap, quick & easy.... I had the same trouble on my push mower this afternoon. The plug was almost new, but on a hunch, I replaced it. Mower fired right up & ran better than it had in a while. Glad to see you working on engines, it is very educational. You will learn a lot more than the teens that play video games all day.....



[Log in to Reply]  [No Email]
Loren

06-07-2005 21:29:14




Report to Moderator
 Davis, in reply to Davis In SC, 06-07-2005 21:14:40  
Care to fill us in on what brand of plug that was? :>)



[Log in to Reply]  [No Email]
DRL

06-07-2005 21:13:02




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-07-2005 20:44:39  
Sure the shear key in the flywheel isn't partially sheared. Will throw the timing off if it is. May start, but won't run very well. Also, possibly the crankshaft is twisted or bent. Also would throw timing off if twisted in the right place. Could be the reason it was put in the trash. When I was in college I did the same as you are doing now. Earned quite a bit of money mowing lawns with lawnmowers left in the trash or junk heap. Usually there wasn't much wrong with them. Key sheared on the flywheel, worn points, rope pulled out, worn out diaphram in the carb, etc. Folks with no mechanical knowledge thought they were shot, so junked them and bought another one. Good luck.

[Log in to Reply]  [No Email]
Coloken

06-07-2005 21:02:14




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-07-2005 20:44:39  
Every thing you describe, including the backfire out the carb, can be caused by the carburator constantly flooding. Had one like that once, swore the timing had slipped, but when i replaced the float valve stuff, it fixed it.



[Log in to Reply]  [No Email]
Hurst

06-08-2005 09:23:35




Report to Moderator
 Re: can't figure what the problem with this motor in reply to Coloken, 06-07-2005 21:02:14  
My 6 hp techumsa did the exact same thing yours is doing. Some how the intake valve was coming sticking. Did you test the compression with a guage or just by the feel? My engine felt good for a 6hp, even with the valve open, but the air would blow out of the carburator, so no gas got to it. Check the valve clearance, and set to about .017 or so normally if you don't have the exact numbers. Good luck.

Hurst

[Log in to Reply]  [No Email]
Michael IN PA

06-08-2005 06:41:16




Report to Moderator
 Re: can't figure what the problem with this motor in reply to Coloken, 06-07-2005 21:02:14  
The newer engines have a solenoid-activated fuel shut off. It screws into the bottom of the carb bowl, and has a pin that blocks fuel from going to the jets. If it is defective, it could prevent starting. If the engine starts with ether, and has gas in the bowl, it might be the shut-off.



[Log in to Reply]  [No Email]
lawnmowerkid

06-07-2005 20:46:35




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-07-2005 20:44:39  
just something i'd like to add, i think its the tuning. how d i set this?



[Log in to Reply]  [No Email]
ppery

06-08-2005 05:45:39




Report to Moderator
 Re: can't figure what the problem with this motor in reply to lawnmowerkid, 06-07-2005 20:46:35  
you may have a sticking valve, or possilble broken retaining clip that holds valve in. if a valve is bad or needs adjusting it will pop back threw the carb. i would take the carb apart and clean and inspect everything. to adjust,you turn the adjustment screw in untill it stops{do not tighten past the point it stops} and then turn screw out 1 1/2 turns out to get it started. run the engine at operating speed and do you final adjustments from there. turn screw one way untill it starts to run rough, then back the screw up untill it starts to run better . if you back the screw up to far it will start to run bad again, you just need to find that good running point in the middle. let us know..perry in michigan

[Log in to Reply]  [No Email]
[Options]  [Printer Friendly]  [Posting Help]  [Return to Forum]   [Log in to Reply]

Hop 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 ]

Home  |  Forums


Copyright © 1997-2023 Yesterday's Tractor Co.

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

Website Accessibility Policy