-= Li'l Red =-

Rustbucket Garage wrote:

You and me both with engine problems. Sounds like compression is good from the video. Those carbs are awful for not running right from what I’ve heard. Could there maybe be something up with the governor? I am not sure being I’m new to small engines, that is just from my frustrations from the wonder that is the vanguard. Hope you get it figured out ok.

Both brakes are good,  rolls fine.  Trans turns fine.  All idlers are new and spin great.  No belt drag.  Pulled a plug and it looked perfect.  Not wet or oily.

Pretty certain this is a case of taking a shortcut to "Send It.." is coming back to bite me.  When I had the engine apart, the valves were acting a bit weird.  Let me explain.  On the compression stroke the valves sealed tight on both sides.  On Top-Dead-Center they didn't seem to seal good.  That logically doesn't make sense to me.  The cam inside looked fine.  Anyway, I figured since it seemed to seal on compression stroke, I sent it.  

So...

I worked over the engine this afternoon.  I found my compression and leak test kits.  I hate to go on, but left side engine I was getting 45psi with leaks.  Right side I got 32psi with major leak.

I knew I should have did a valve job.  I hate pulling valve springs.  I have a briggs tool now, so this should be easier.  I guess I have a new project.  Should I screw up, I do have a couple engines to pull new valves.

Rustbucket Garage wrote:

Got to thinking... is there maybe a gummed up jet somewhere? Also could it maybe be that one coil wire is bad? Just a thought that I had. Don’t have any more cause thinking hurts too much for me

Also a new coil pack.  Gets really good spark.  Probably why it runs at all.  LOL

Hahaha! I knew you would've already checked everything I said, should have known better! You wont screw it up I've got faith in ya! 

I knew you’d figure it out. I saw a video of a this British fella who went and bought an utter pile of junk.. think if he sneezed it would have disintegrated. Thing had absurdly low compression, can’t remember the exact figure but I think it was around 18 psi. Somehow it ran. If you are interested:

Yeah it sounds like a valve grind is order for the ol' girl Mighty.

In your video at about 4:43, when the engine starts do you hear that slight squeaking sort of sound as it fires and idles? Also how the engine doesn't bark to a start, it takes a few seconds almost like it's building up. Those are definitely indicators of a valve out of 'er. In fact, most times you hear that on an engine it's a valve not seating. I would say it needs the clearances done as well as the valve faces and seats. She'll probably be like new then.

By the way, Red's looking killer!!

AllisKidD21 wrote:

Yeah it sounds like a valve grind is order for the ol' girl Mighty.

In your video at about 4:43, when the engine starts do you hear that slight squeaking sort of sound as it fires and idles? Also how the engine doesn't bark to a start, it takes a few seconds almost like it's building up. Those are definitely indicators of a valve out of 'er. In fact, most times you hear that on an engine it's a valve not seating. I would say it needs the clearances done as well as the valve faces and seats. She'll probably be like new then.

By the way, Red's looking killer!!

Thanks @AllisKidD21!  I tore into it today and it's looking far more than just a valve grind.  I need about .005 off all but one valve that may need around .01 off it.  The worst part is... and I actually checked this in one of my earlier videos.  For some reason now, the pistons are also really sloppy.  Lower left is getting oil past the piston.

Oooof. That definitely isnt helping your compression issues. Might be a good excuse to swap that v-twin on.


I would say maybe the rings are worn if the cylinder walls look good, and I cant see why the rings would go from un-stuck to stuck. Does it have aluminum cylinder walls? Or is it sleeved?

BlakeGroce wrote:

Oooof. That definitely isnt helping your compression issues. Might be a good excuse to swap that v-twin on.


I would say maybe the rings are worn if the cylinder walls look good, and I cant see why the rings would go from un-stuck to stuck. Does it have aluminum cylinder walls? Or is it sleeved?

The plot thickens....

First a response...
I thought about getting a ring set and a light honing of the cylinder walls.  They are finely scored and the left side has some residual marking from it having a little rust it appears at some time.  Sleeved?  I'm pretty certain they are.

OK, back to the plot thickening.  I drained the oil in prep to maybe tear into it and replace the rings.  I realize now Ring sets are going to run around 60 bucks, as I don't care to have some china junk on such a precise part of the engine. Now for the even worse news... the oil was all glittery.



It's looking like Red wants that V-Twin. 

Sounds like either way the motor has to come off again eh?

I would definitely say that bogging has something to do with rings. That's kind of how my brother's 19 horse acted just about 3 times worse. His was actually MISSING a compression ring. I'll bet one of the compression rings are worn out.

Not sure what to tell you on the glitter though. Only thing I would know to do is to pull er apart again.

Engine is already off.

Not going to lie, I winced a bit when you talked about the metal filings. That sounds painful. How fine is the scoring? If you can’t feel it with a finger you are fine. Hope the V twin works out better for ya

I can’t feel them at all. I’ll going to weigh the options more tomorrow. I would like to pull a cylinder out (worst one) and see how bad it is. If the crank is scored too. That will sway my hand. Honestly, I would like to keep the oppy but if it starts adding up $$ to fix it back. She’ll become a parts engine.

If it was me, just being how I am, I would run it like it sits or swap on a new motor up until I'm ready to throw a whole bunch of billet parts at it.... I mean, you know that's what Red is asking for....

Spent some time with the engine today.  Pulled both pistons out. The crank and rods are NOT scored.

This is the worse cylinder.  I think a honing will clean it up.  The other (upper) is in pretty good shape.




Rods look great!  Almost brand new?



Crank looks just fine too!



Starter inside was toasted to a crisp.  Replacement is needed.

So with all this, I have decided to give this engine some love and get it back up and running.  I am replacing the rings.  They looked pretty burned.  I found some NOS rings for decent price and ordered them.  ($24 a piston)  I also pulled a trigger on a new starter.   I also worked on the valves.  In research, there should be a little bit of gap on the input I believe for compression release.  But it was only about .001?  I forget.  Mine was WAY more than that.  I took it down to just turn it and just for a fraction of the cycle.  Great seal on compression stroke.  Block is ready for parts.

On a side note, I will need a new set of head gaskets as my new ones tore on removal.  There is one thing on this engine that drives me nuts.

These 2 pockets below the inspection plate.



Oil gets down in them and sludges up.  I am so tempted to drill out return holes in them.  Thoughts?  I have tried to RTV the area above them, but oil still gets in there.

If you "know a guy," I would have someone check the piston-to-wall clearance to make sure it's not egged shaped. Also check the cam for play. I've had a cam eat up the sump before. Not saying that's where your metal shavings came from, but if by some chance that's not remains of the rings you found in the oil... Better to just make sure everything is good before you put a bunch of work into it. That's where I went wrong when I had to put shift keys in the MM.

To build off what @Murraymountain said if you have a micrometer on hand or know somebody who has one take the 5 minutes to check the crank journals on a couple axes to make sure it’s in round and in spec, that probably isn’t the cause of your shavings but you can’t be too careful. Also if you hone that cylinder be very light with it. Those aluminum blocks are easy to overbore. Good luck with the rebuild!

The shavings was something new to this oil change. I did polish the intake and exhaust... maybe cleaned them good. I think there is a good chance that got into the block. Or... I was cutting some metal. That could have gotten in too. I saw no evidence of where it could have come from. I did check cam play. It was good. I didn’t check roundness of cylinder wall. I can do that tomorrow.

A bore guage will let you check the cylinder for out of round and taper, or take a top ring to and use it to check the ring end gap in the top and bottom of ring travel in the cylinder. You should be fine giving it a honing too, the oppys have cast iron cylinder sleeves.

What did you set your valve clearances to?

Good Idea on using an old ring to check too.  I may try that later.

I set the intake to .004.  One was already there, the other had no gap.  I got it up to .004.  The exhausts were sitting around.005, I bumped them to .008.

Seats an valve mating surfaces looked great!  Didn't feel I needed to lap them.

Oh okay, your clearances should be alright. A good way to check if a valve is seating is put it in the block, apply good pressure to it with your thumb and try to turn it back and forth. If it turns real easy it's not seating right.

They are seating really well.  No wiggles.

Drilled out those pockets so oil doesn't sit in there to coagulate. Now the block needs a good cleaning to be sure not to get any shavings in there. 



Anyone know what this nifty tool is for? 



I'll post the answer tomorrow if no one gets it! 


Waiting for some parts to come in at this point.

i don't remember what it was for but i do remember my grandpa had one like it in his tool box when i was a teen

Since no takers...

It's a piston groove cleaner/cutter.  

Well I guess I learned something today! Never knew they had those. Cool!

Boy that's pretty neat, I don't think I've seen one of those before either. Another good way to do it is snap one of the old rings in half and use the sharp broken edge to clean the grooves out.

'Course that only works if you're replacing the rings.

@AllisKidD21, that was my plan to use an old ring since I got new ones.  My dad whipped that out and said, here you go.  You can keep it.  Worked like a charm and was super easy.