B&S 17.5 ohv Starter problem

[expat]

We have this on our ride on mower, lately starting (cranking) has been very hit and miss.
Initially I thought it must be the battery as it was about 8 years old, but a new battery does not seemed to have resolved the problem.
With the power cable disconnected from the starter motor, I get a full 11.8v when I turn the key to start. But the starter motor just growls or barely turns the motor.
50% of the time it will work just fine, but it tends to be getting worse.
Is the starter motor (realistically) serviceable? or should I just plan on getting another?

PS. I just ran a Jumper cable from the battery + direct to the starter motor, Still no joy:-(

 

[Recalculating]

I have an older Troy-Bilt with the B&S Vanguard engine. It has had the plastic cog that engages the flywheel broken, teeth missing and broke where it affected the ability of the starter to spin. It sits on the top of the starter with a spring mount.

This part is replaceable and may be the ill of your problem.

 

[old1]

I am not real familiar with that starter, but it kinda sounds like maybe the brushes are gone. As far as repair goes, some briggs starters are quite simple and economical to repair, others are a pita, and expensive. Also, if it is anything more than the brushes, best to just replace.

 

[Lubener]

My 24 hp B&S (ohv)would only grunt at times and I had to manually rotate the engine off of the compression stroke to get the engine to turn over. Battery replaced no improvement. I was told to adjust valve clearance and since I did this, I had no issues. Mine was an overhead valve design. Do a search for valve adjustment on Briggs and Stratton. It appears to be a common problem and compression gets affected.I once had to replace a chewed up top gear on a stater, it only spun and wouldn't engage the flywheel, never actually wore out a starter so I doubt that is your problem.It would take a lot of use and abuse.

 

[Nukeman7]

Originally Posted By: Lubener
My 24 hp B&S (ohv)would only grunt at times and I had to manually rotate the engine off of the compression stroke to get the engine to turn over. Battery replaced no improvement. I was told to adjust valve clearance and since I did this, I had no issues. Mine was an overhead valve design. Do a search for valve adjustment on Briggs and Stratton. It appears to be a common problem and compression gets affected.I once had to replace a chewed up top gear on a stater, it only spun and wouldn't engage the flywheel, never actually wore out a starter so I doubt that is your problem.It would take a lot of use and abuse.


+1...your valves are too tight and not releasing the compression adequately, causing too much backpressure.

 

[old1]

Yup, I forgot about the valve adjustment. That could very well be the problem, but they are not to tight, they are to loose, not letting the compression relieve itself. worth a shot checking though

 

[expat]

Should the valves be adjusted to B &S spec, or is there a revision?

I have tried turning the Flywheel to get passed compression, but it did not seem to help.

 

[old1]

Factory spec's, but if turning it past compression didn't make it spin good till the next comp. stroke, that probably isn't it. Have you tried jumping it with a known good battery? Like from your car? Or hooking jumper cables from known good battery directly to the frame of mower and positive cable directly to the starter ?

 

[expat]

Still not sure about the battery, so I have inserted a new battery (that I had for a friend) for test purposes.

I want to adjust the valves while I have it in the shop.
I understand the specs vary by model #
Where would I find the model #

 

[expat]

OK found it on the valve cover.

I was looking on the block.

 

[expat]

Valves adjusted, but they were not too far off, just .002 too much on the intake.
Gave everything a general clean-up and took it out to round up some leaves.
Worked just fine, and started every time.

I guess we'll see how it goes.

Thanks guys.

If you have any other ideas I'm still open to suggestions.

 

[Lubener]

Glad it worked.I do not have a lot of faith in these newer B&S engines.I wonder if they are even American made anymore. I recently pulled out an old (1973)cast iron Tecumseh 12HP out of a Bolens to do some internal work on it. That lump of iron had to weigh 175 LBS.I doubt the newer engines weigh half of that.

 

[wvrailroader]

If this is a Briggs Intek engine, there is a special procedure for adjusting the valves due to the compression release mechanism. The engine has to be taken to TDC and then turned clockwise until the piston goes down 1/4", then the valves can be adjusted. These Intek engines are also bad to break this compression release mechanism, which makes it pretty well impossible for the starter to start them. Replacing the starter is just a waste of money if this is the case.

I have repaired several of these engines with this problem and it requires the replacement of the camshaft, as the compression release is attached to it. The parts will cost about $100. In my opinion, the compression release is of a pretty poor design, as they always break off where they attach to the cam (the shaft holding them to the cam gear is a little half moon shaped shaft about 1/8" diameter).

Hope this information helps.

 

[expat]

Originally Posted By: wvrailroader
If this is a Briggs Intek engine, there is a special procedure for adjusting the valves due to the compression release mechanism. The engine has to be taken to TDC and then turned clockwise until the piston goes down 1/4", then the valves can be adjusted. These Intek engines are also bad to break this compression release mechanism, which makes it pretty well impossible for the starter to start them. Replacing the starter is just a waste of money if this is the case.

I have repaired several of these engines with this problem and it requires the replacement of the camshaft, as the compression release is attached to it. The parts will cost about $100. In my opinion, the compression release is of a pretty poor design, as they always break off where they attach to the cam (the shaft holding them to the cam gear is a little half moon shaped shaft about 1/8" diameter).

Hope this information helps.


It says 17.5 I/C I got the valve clearance spec after looking up the model number from some website.
It did not say anything about 1/4 past TDC, I just adjusted them at TDC compression.

 

[bubbatime]

Pretty common problem. As you found, the valves needed adjusted. Good reminder.

 

[ATS-V]

Lets not forget the head gasket problems these motors have!

I was blowing gaskets every 2-3 years, last time I copper sprayed the gasket before assembly and it just finished its 5th year. I'm sure it will let go a some point since there isn't enough meat on the one side.


Originally Posted By: wvrailroader
If this is a Briggs Intek engine, there is a special procedure for adjusting the valves due to the compression release mechanism. The engine has to be taken to TDC and then turned clockwise until the piston goes down 1/4", then the valves can be adjusted. These Intek engines are also bad to break this compression release mechanism, which makes it pretty well impossible for the starter to start them. Replacing the starter is just a waste of money if this is the case.

I have repaired several of these engines with this problem and it requires the replacement of the camshaft, as the compression release is attached to it. The parts will cost about $100. In my opinion, the compression release is of a pretty poor design, as they always break off where they attach to the cam (the shaft holding them to the cam gear is a little half moon shaped shaft about 1/8" diameter).

Hope this information helps.

 

[Lubener]

Repeated head gasket issues usually are the result of a warped head or installation errors.

 

[ATS-V]

Originally Posted By: Lubener
Repeated head gasket issues usually are the result of a warped head or installation errors.


In this case it's a design flaw. There's not enough meat on the one side and always blows the same spot.