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BRIGGS & STRATTON 7.75 HP No Start

#1

H

HaroRider

Hello everyone, I am new to the forums and looking for some help. I have a Craftsman Pressure washer with a 7.75 B&S engine.

This engine has not started and I tried to diagnose it. Its getting spark and fuel. It seemed very easy to pull the pull string so I leak down tested it and seen the intake valve was leaking.
I pulled it apart, replaced the valve guide, lapped the valves and put a new head gasket.

My issue is I don't really know what the valve clearances should be on the engine. Model# 11P902-0120-B1.
I tried a few different clearances but could not get it to start, it only back fired a bit out of the intake.

Can anyone assist me with this information and perhaps how to properly adjust these valves?

Thanks, Tom


#2

Scrubcadet10

Scrubcadet10

if the proper valve clearance does it fix it, i would look at the flywheel key.
I believe the spec is .004 to .006 on(*see ilengine's post) both valves.


#3

ILENGINE

ILENGINE

.004-.008 actually. With the piston slightly past TDC compression stroke which is both valves closed.


#4

H

HaroRider

Thanks for the responses guys. its .004-.008" for both valves? If I set them both to .006 then that should be fine?


#5

H

HaroRider

I ended setting them both to .006 and checked the flywheel key. I am still not getting this thing to start. I am lost at what to do and pulling my hair out. I never had an engine this difficult to start.

I am thinking of doing a compression test next, anyone know what the compression on this engine should be?


#6

H

HaroRider

A few pictures

Attachments









#7

H

HaroRider

Not sure anyone can help. I took apart the cam to see if something is going on.

Does it look like one of these cam lobes spun or are they supposed to be so close to point the same direction?
The intake and exhaust opened so close together.

There is some damage on the cam lobe, but I don't think that would cause the engine to not start?

My thought is something happened and the cam lobe was hit hard and spun.

Attachments





#8

S

slomo

New cam time. Lobe is all gnawed off.


#9

H

HaroRider

Any idea what can cause this?


#10

R

Richard Milhous

Debris in oil or lack of oil. The damage on that cam lobe has probably transferred to the valve/pushrod/lifter (I know nothing about this particular engine or its valve train).


#11

H

hlw49

You get new lifters when you get a new cam.


#12

B

bertsmobile1

You get new lifters when you get a new cam.
Not any more .
Not only are the new came nea twice the price but they come with nothing other than the cam
Welcome the to new B & S


#13

H

hlw49

Bummer I just got one for the 31 cubic inch engine that had them.


#14

B

bertsmobile1

Send it back ;)


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