Compression release made easy?

Mr.B.

Mr.B.

Well-Known Member
My build uses a old Wisconsin engine and I’d like to be able to pedal start it old school on the stand,

But it ain’t happening without a compression release.

I know msrfan has a real nifty system for his 5HP Briggs projects, but I’m hoping there may be a less complicated way of just using some sort of valve in the top of the cylinder head???

This isn’t the original head and already has some broken fins so I’m not worried about hurting the antique value.

This will be completely new ground for me so...

Any thoughts, tips, or suggestions?

Thanks,

-Kirk
 

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I know some older dirt bikes had a cable operated compression release that screwed into the head. Prolly could retrofit one of those,or one from a solex or hongdu would work.

I have seen old John Deere hand start tractors that used a simple small brass petcock. No reason why one of those wouldn't work.
 
Maybe one from chainsaw, a simple drill and tap install. Press it down to start, when it cranks it pops up and closed automatically.
 
I don't think location matters. I would put it where it is easiest to operate. Where those broken fins are is a good spot.
 
I've had a compression release from e-bay sitting around waiting for the right engine. I will watch this thread develop. Mr. B killer ride!
 
Kind of off topic - but would a compression release work on a vertical shaft B&S lawn mower engine to reduce the kick back?

Chris
AKA: BigBlue
 
Good idea, Might work to allow easier starting while using the lighter weight flywheel to save some weight.
 
BigBlue said:
Don't know if this would work, but here's one for a chainsaw:

http://www.baileysonline.com/itemdetail.asp?item=QH 50371 5301

Good Luck,

Chris
AKA: BigBlue
Click to expand...

cannonball2 said:
Yep thats the kind I was referring to, dont know why it wouldnt work
Click to expand...

Yep,

That sure looks interesting, thanks!

So they’re “automatic”?

Or do you have to push, pull a button?

Or can you push, pull a button- I actually like the idea of having some fiddle factor involved...

-Kirk
 
You do have to push it down, it releases automatically. If the engine hits but doesnt start you have to push it again. Maybe you could change out the plastic cap for a brass knob or something to get a vintage look. These are very trouble free. I dont recall seeing one replaced.
 
I missed this thread until now. I repair chainsaws at my work and noticed the little compression release was a very compact item. I haven't used one yet but was thinking of fabricating a bracket with a lever to push it in by a cable up to a handlebar lever. That would allow you to hold it in as long as you wanted to while pedal starting, and would also be available for compression braking. Just a thought.
 
Mr.B. said:
My build uses a old Wisconsin engine and I’d like to be able to pedal start it old school on the stand,

But it ain’t happening without a compression release.

I know msrfan has a real nifty system for his 5HP Briggs projects, but I’m hoping there may be a less complicated way of just using some sort of valve in the top of the cylinder head???

This isn’t the original head and already has some broken fins so I’m not worried about hurting the antique value.

This will be completely new ground for me so...

Any thoughts, tips, or suggestions?

Thanks,

-Kirk
Click to expand...
I realize this is a very old post, not sure exactly how I got here, but I'm glad I did and got to see the pic you posted of your bike. That is definitely very high up on my list of cool bikes. It's beautiful on a few levels. I love the long handle, is that to engage the drive belt? Early on I was faced with the decision of how I should set up 2 different brakes and a clutch because while I suppose I could pull the clutch and use a finger to engage my front brake, it just looks sloppy having 2 levers on the handlebars. I don't care for the dual lever either because I like having the option to increase front brake pressure a bit more as I slow down, but not in the rear. I toyed with the idea of a suicide brake handle for the rear brake, it would look so awesome.... But alas, my excitement was short lived when it quickly dawned on me that I don't posses the necessary 3rd hand to operate my brake lever on the right so I'm right back where I started if I do that. I digress, you have a pretty cool conversation piece there. That engine will most likely outlast my next 5. The frame is such a perfect match for such an awesome piece of history. I love old engines, I suppose that's how I got here come to think of it. Someone mentioned a compression release valve and it got me thinking of old engines my Grandfather would tinker with. They started with a crank in some cases and the compression was tight to say the least. If she misfired in the slightest she'd kick that crank back at you like a mule and you'd better be ready to let go of it and stand back because those things would snap an arm bone like a toothpick. Sad really, 50 years from now my son won't see very many engines left from my time (not that there's many worth keeping for that long), but I'll bet there will still be a few like yours still plugging along. Sorry for the long post, just wanted to give you credit for an awesome build. A lot of idiots would call it trash, but I think between the bike and the engine, there are some stories there, a lot of them. That's class and a perfect use of some historical artifacts that may have gone to waste if left in someone else's hands.
 
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