Onan B43M Valve Keeper

[Sea-Duck51 55]

I just got done putting the motor in after replacing Hydro seal,before the tear down it started bogging,black smoke,having fooled with the carb,it was sitting for some time thought it was probably bad float so rebuilt,new brass floats and when I fired it up had tremendous back pressure out of carb,long story short pulled plugs and no compression on one cylinder,after pulling intake/exhaust determined Intake Valve stuck open,pulled inspection covers and found this little piece of metal and appears valve keeper is bad,question is can I fix this without pulling the head,motor was a reman that PO had installed,supposedly low hours,what's the verdict?.

[953 nut 51,682]

Several years ago I made a little device that allowed me to change valve seals on an OHV engine without pulling the head. I took an old spark plug and knocked out the porcelain leaving only a metal sleeve and welded a male air fitting to it. Screwed it into the head and hooked up the air hose while compressing the spring tool. The air pressure holds the valve closed while you are working on it. This should allow you to insert a new keeper with the head in place.

Hope this helps.

[Sea-Duck51 55]

Great idea..after some research thinking it's the vale spring retainer washer and not the keepers,looks like the shoulder broke of allowing it to ride up on the valve stem,what really blows is going to be the SNOW,expecting 6-12" tomorrow and worked all day getting the horse back together,going to have to break out the shovel...ugh.

[gwest_ca-(File Mod) 10,498]

If you have a compression tester with a hose on it you may have everything in it you need. You would need to remove the valve core.

Remove the valve keepers with air on the valve.
Release the air and lift the valve to replace the retainer.
Put the air back on, compress the spring and install the keepers.

Hardest part is likely coming up with a retainer real quick.

Garry

[Sea-Duck51 55]

I've been looking at different valve spring compressors online,so many choices,anyone have a favorite?.

[953 nut 51,682]

   I have used one like this on flathead Fords and Kohlers for years, Works great.

[Sea-Duck51 55]

The mystery is solved i hope,was able to use a small rod to hold the vale shut through the spark plug hole and with a large screwdriver compress the spring,to my surprise there was only one keeper not two which explains why the retainer washer was damaged,this was a reman engine the PO found at a local small engine shop that was "rebuilt" ,well the valve must have been done on a Monday or Friday or possibly just before closing time,how does one forget one of the keepers?,looks like I'm going to pull the head if the valve stem is boogered up,ordered a spring compressor so we'll see.

[953 nut 51,682]

 A small dab of grease on each keeper will hold them in place for you. I have a pair of specialized spring loaded magnetic keeper holders, but if it is a one time job the grease will do just fine.

[boomers_influence 106]

sea-duck
i would NOT bet my life on this BUT
i'm 99% sure that you have a P series short block,
NOT a B 43M
the P keepers have 3 grooves,
the B keepers have 1 groove.
if you do need keepers or retainers i will give you some.
boomers_influence@yahoo.com
thank you. boomer ( the used onan engine parts guy,also NOS and new )
 

[Sea-Duck51 55]

This is what I know,only had the D160 W/FEL for several months,PO had it for over 20 years and when the original Onan went bad he was able to find this one at a local shop that had been sitting on the shelf for years,supposedly rebuilt?,judging by the condition of the LH Cylinder valves,springs only the RH was worked on or remaned.The exhaust valve has Two Keepers on it,thx for the offer but ordered new keepers,retaining washer,should be here by weeks end,attached a pic of I.D tag and block casting #.

[boomers_influence 106]

sea-duck
the cast # 170-4347 on the block, ( i have one in stock )
confirmed that you have a P block,
with B sheet metal and other parts.
the valve parts are not inter changeable,
UNLESS the valve guides were replaced
with B guides and related parts.
B valve stems are 11/32. ( .343 )
P valve stems are close to 9/32 ( act .280 )
ALL onan twins use 2 keepers per valve.
thank you. boomer

[Sea-Duck51 55]

It sounds like I have a Heinz 57 motor,well the keepers and retainer are on the way,should be here next day or so,valves springs,keepers and all look different from LH Cylinder so I'm hoping your right and they changed it,thanks so much for the info and if the parts don't work I will defiantly get back with.

[Sea-Duck51 55]

sea-duck
the cast # 170-4347 on the block, ( i have one in stock )
confirmed that you have a P block,
with B sheet metal and other parts.
the valve parts are not inter changeable,
UNLESS the valve guides were replaced
with B guides and related parts.
B valve stems are 11/32. ( .343 )
P valve stems are close to 9/32 ( act .280 )
ALL onan twins use 2 keepers per valve.
thank you. boomer

So if the ones I ordered for a B43 don't fit are these the ones I need for a P series block?
110-3487 Retainer Washer
110-3511 Keepers
Thx.

[boomers_influence 106]

sea-duck
yes those part # are correct
for a P engine. ( small block )
thank you. boomer

[Sea-Duck51 55]

sea-duck
yes those part # are correct
for a P engine. ( small block )
thank you. boomer

you are correct,received the parts today and they are much bigger so ordered the correct ones,also the mystery is solved,piece of metal I found is the top ring of keeper,rest is fused to the retainer washer,valve looks to be o.k so will sit back and wait for new parts,if anyone needs 2 keepers and retainer washer for B43 PM me and there yours,don't have any use for them.

[boomers_influence 106]

sea-duck

before you reassemble please read page 10-4,

from the P series onan service manual.

it covers how to check the valve rotators.

thank you. boomer

[sorekiwi 761]

I am not sure if this is relevant or not, but this thread has made me remember something from putting a 20 hp Onan back together about 5 years ago.

 

There is a little cap that sits on the very end of the valve stem.  I noticed that all 4 of the caps in my engine were long enough to touch the tops of the valve keepers - in effect these caps were sitting on the keepers and not seating on the end of the valve stem.

 

I could find no information on this in the manual, or anywhere on the internet.  But it didnt seem right to me so I shortened the "open" end of that cap so that it cleared the keepers.  I believe the keepers are better secured by the taper in the valve spring retainer, and the cap pushes directly on the top of the valve stem when the lifter decides its time to open the valve.

 

Hope my explanation makes some sense...

 

I have no idea if this is relevant to your situation, but as soon as I saw that loose keeper I remembered this.

[Sea-Duck51 55]

11 hours ago, sorekiwi said:

I am not sure if this is relevant or not, but this thread has made me remember something from putting a 20 hp Onan back together about 5 years ago.

 

There is a little cap that sits on the very end of the valve stem.  I noticed that all 4 of the caps in my engine were long enough to touch the tops of the valve keepers - in effect these caps were sitting on the keepers and not seating on the end of the valve stem.

 

I could find no information on this in the manual, or anywhere on the internet.  But it didnt seem right to me so I shortened the "open" end of that cap so that it cleared the keepers.  I believe the keepers are better secured by the taper in the valve spring retainer, and the cap pushes directly on the top of the valve stem when the lifter decides its time to open the valve.

 

Hope my explanation makes some sense...

 

I have no idea if this is relevant to your situation, but as soon as I saw that loose keeper I remembered this.

 

Thanks for the advice,yes it makes sense,the cap could have been beating on the keeper so to speak,judging by the piece that broke off hoping that it was installed wrong or possibly defective but will explore all possibilities.

[Sea-Duck51 55]

I got the retainer,keepers in no problem and while adjusting the valves much to my surprise they were gapped bass ackwards,that's right whomever remaned the engine was either dyslexic or having a bad day,didn't believe it at first but checked several times after rotating the engine,noticed before it was load and obnoxious,rattled,some popping and spitting but now she purrs like a kitten,that explains why the keeper got destroyed,thanks for all the help guys and btw the whole point of this was the front hydro seal and no more leak,was a long process but it was worth it,thx again.