Low compression Help!!?

[cyclefvr2]

all that work it would be a waist to not put in a new set of rings!!!

i woulsd lapp the valves while your at it- a drill ,on the tip,and some valve grinding compound works great!! makes them seal great again
just remember to be patient!, and have fun,and the bike will run like new

[ameen]

How can i tell if i can need to replace the rings or not?

Also, anything else i should check/do while in there? Any good upgrades?

Thanks

[Dogma]

How can i tell if i can need to replace the rings or not?

Also, anything else i should check/do while in there? Any good upgrades?

Thanks

My copy of the Clymer repair manual describes tests for rings, etc.

[feelergaugephil]

How can i tell if i can need to replace the rings or not?

Also, anything else i should check/do while in there? Any good upgrades?

Thanks

Take the rings off the pistons, slide down the bores as if they were on the pistons and check the gap with a feelergauge, refer to manual for measurements.
Take your cylinder head/bores to any car dealership, go to the mechanics and ask can you use the vat (I think thats the name) machine which cleans hardened grease/oil from engine parts, if they are a nice crowd, they will let you use it.
Failing that, use purple power or simple green strong and scrub away!
I bypassed all that and glass beaded my engine, BUT if you go that route, make sure ALL the beads are out, if you dont the engine will last 5 minutes............

[ameen]

If I was to re do the valves, what all would i need to replace?

[feelergaugephil]

You'll need the correct valve compressor tool, you'll need valve stem seals and don't forget to lap valves in AND DONT GET VALVES mixed up with each other, make sure they go in the correct place.

[ameen]

it says something in the manual about not reusing valve guides. Can i reuse the ones in there?

[chef1366]

it says something in the manual about not reusing valve guides. Can i reuse the ones in there?

I think they are referring to valve oil stem seals.

[chef1366]

When checking ring gap make sure you push the ring in the bore with the piston to keep it even before taking measurements.

[rapidray]

Contrary to the post above by someone that is NOT an engine builder, do NOT use a drill to lap the valves!!! Ray.

[DimitriT]

I'm coming kinda late to this. Had the same thing happen to me with the
compression tester adapter. Last time I use a cheap tester on my motor.

Well, like you I was faced with the task of pulling the head, drilling out
the adapter (which I did using a hand drill), inserting a thread insert (use
some kind of high temp permanent thread lock or it will pull out of the
hot motor next time you remove the plug).

I also replaced the valve seals (wound up damaging a seal and had to redo
the head strip down) and the rings (wound up bending a ring and having
bad compression in one cylinder - replaced during second strip down).

Here's what I suggest: fix the hole and button it up. Leave the base
gasket alone. There's a guy on ebay who's dumping head gaskets for
$25 or so (http://cgi.ebay.com/ebaymotors/NOS-1...Q5fAccessories).
I'm running one of his and its dry.

Everything seems simple but the tiny details will cost you big time. You
might get it right the first time but its likely there will be something you
miss. It's also likely that with just 18k miles, the bike will run great on the
current rings and valve seals. You can always go back and strip it down
if there's a problem. Just my .02 cents.

BTW, I have some new OEM 550 std. rings for sale if you want (3 sets I
believe).

A year and a half later I finally got the bike running as well as it did just
before I did the compression test. I stuck through it and learned alot but
I would rather avoid the experience.

[ameen]

Thant sounds like good advice. Any reason that you recommend leaving the base gasket alone? I already started taking mine off....


Thanks

[DimitriT]

Thant sounds like good advice. Any reason that you recommend leaving the base gasket alone? I already started taking mine off....


Thanks

Because to get it off you need to remove the cylinders which would open a can of worms.
If you already took off the cylinders then you should replace the base gasket along with
the oval shaped rubber o-rings. I strongly recommend you get someone to help you
put the cylinders back on as its a hard job with one set of hands. Also make sure you
get every last bit of gasket and dirt off the surfaces. I used a utility knife blade to carefully
shave off any bits stuck on. This way she'll be nice and dry for many years. Also apply
a little grease to both side of the gasket. If you need to strip it down again in the next
year, the old gasket will just slide right off and you don't need to go through the whole
cleanup phase which is the most time consuming part IMO.

[ameen]

OK.. I am getting ready to start assembling this thing soon. A couple of the rods that stick up from the block came unscrewed when i took it apart. Is there anything special i should know about putting these back in? anyone know the torque?
Also, are these bolts all reusable or do the yield to torque and need replacing?

Thanks
Ameen