Export thread

Please help

#1

S

Swage33

I have a 17.5 hp B&S intek ohv on my 42" mtd riding mower. So far I have replaced the battery, solenoid, spark plug and have also had the starter rebuilt. I'm getting fire to my plug, the exhaust is clear but when I try to start it all it does is backfire through the air intake. Why is it doing this and what can I do to fix it?


#2

P

Phil G

Swage33 said:
I have a 17.5 hp B&S intek ohv on my 42" mtd riding mower. So far I have replaced the battery, solenoid, spark plug and have also had the starter rebuilt. I'm getting fire to my plug, the exhaust is clear but when I try to start it all it does is backfire through the air intake. Why is it doing this and what can I do to fix it?
Click to expand...

Have you got a model code and type code? all it does is backfire through the air intake
 Has to symptons of a sheard flywheel key or sticking inlet valve. What's the compression like?

Did it stop in use?

Good luck, Phil :smile:


#3

M

mechanic mark

FAQ | Lawn Mower Safety Tips | Briggs & Stratton


Results


#4

S

Swage33

model 31G777, type 0172 E1, code 090601ZA. No, didn't quit in use, I was able to start it a few weeks ago by jumping over the solenoid. When it stopped cranking at all I feared I burned up my starter so I had it tore down and checked out...the guy said there was nothing wrong with it. SO...new battery, solenoid, spark plug...it cranks now from the keyswitch but it wont start. I did notice something when I had the cover off of the engine...when cranking, the engine blew air out through the air intake....could I be cranking backwards?


#5

pugaltitude

pugaltitude

Compression related component has failed.

Head gasket or valves.

Any oil in intake?


#6

S

Swage33

no, no oil in intake


#7

pugaltitude

pugaltitude

Starter motor wouldnt allow to turn backwards as pinion would not engage flywheel unless its seized in engage position.
Start by removing rocker cover and inspecting valves and push rods and checking valve clearances https://www.google.co.uk/url?sa=t&s...wQFjAA&usg=AFQjCNEjPDkxPVZBZvd9OX_uIqlaL9Pc5w


#8

N

nfk

Could also be compression release not operating properly


#9

Fish

Fish

Just remove the valve cover and tell us what you find....


#10

M

mechanic mark

Swage33 said:
model 31G777, type 0172 E1, code 090601ZA. No, didn't quit in use, I was able to start it a few weeks ago by jumping over the solenoid. When it stopped cranking at all I feared I burned up my starter so I had it tore down and checked out...the guy said there was nothing wrong with it. SO...new battery, solenoid, spark plug...it cranks now from the keyswitch but it wont start. I did notice something when I had the cover off of the engine...when cranking, the engine blew air out through the air intake....could I be cranking backwards?
Click to expand...


Adjust valves per manual.


#11

grassroots

grassroots

I had this problem with my Husqvarna. Turned out to be a bent push rod on the inlet valve. Replaced that and all was fine for a while. However, I soon had the same problems again so, after taking the cover off the valves, I found that the tappet on the exhaust valve was lying on the floor of the valve cover. What was happening? Turns out the rocker arm stud [exhaust] was loose. This caused the tappet to fall down and jam in the inlet valve spring. The stud was thread locked in place and the problems went away! :)


Footer Links 1

Top