Ohlsson & Rice: Stumped on Engines Not Starting

[CNew 403]

Ok, so I’m in need of some advice.  I recently thoroughly cleaned and went through an Orline Trimmer and a Drillgine. After putting everything back together both engines had super clean and adjusted points to 0.020” producing nice hot blue spark (plug set at 0.030”), adjusted the coil/flywheel to 0.010”, completely cleaned carburetors with new diaphragms and gaskets, needle valves adjusted to 1 1/2 turns out from seated, set the Governor linkage to a low notch, and everything looks to be in good order. Upon trying to start both engines I get nothing, not even a hint of them trying to fire. They both seem to have excellent compression and are getting fuel to the carburetor (I actually flooded a couple of times during the process with some signs of fuel spitting out the muffler).  Is there maybe something basic I’m overlooking? I didn’t replace the seals on either engine but they looked in decent condition.

[CNew 403]

Success, I just got the Drillgine running. It will take some additional tuning to dial it in but it sounds great and I’m excited to see it purrr!

[Wallfish 691]

Glad you got her going. To me it sounds like it might've been flooding. Carb needle opened too far.

If the seals are leaking too much it will be difficult to dial in the carb. Sometimes you can get them to start easy but not run right and/or run right but not start easy. Once you get playing around with these enough, you'll learn quickly.

[CNew 403]

Thanks John, I’m definitely learning the quirks on these things.  It was a nice feeling when the Drillgine finally fired up, its such a cool tool. 

 

After some further messing around on the Orline Trimmer it appears that maybe the carb primer isn’t really working after all.  I rebuilt everything but it doesn’t seem to be pumping. I’ll have to open it up again to see what’s going on in there.

[Webhead 95]

Also, sometimes if you just walk away from them for a while, come back and try again, they fire right up and run like a top! Don’t forget to make sure that your fuel tank is venting properly.

Edited March 29, 2019 by Webhead

[CNew 403]

You’re spot on, that’s exactly what happened on this Drillgine

[factory 483]

17 hours ago, CNew said:

After some further messing around on the Orline Trimmer it appears that maybe the carb primer isn’t really working after all.  I rebuilt everything but it doesn’t seem to be pumping. I’ll have to open it up again to see what’s going on in there.

 

Did you check the rebuilt carb using the method below before refitting?

I also sometimes add a length of fuel line & check it will actually pump fuel before refitting.

 

On 2/16/2015 at 6:03 PM, Wallfish said:

Try connecting a clean piece of fuel line to the carb and blow into it. It should only pass air when you push the primer button and the little ball should check valve the air when you suck air out. If air is passing without pushing the button you will need to inspect inside and find out why. The arm may need adjusting, check valve ball is stuck or needs replacing, ect, ect.

If it's not the tank or carb, then it could be the shaft seals letting air in, also dirt can sometimes get trapped in the reed valve (keeping it open).

 

David

 

P.S. Did you sort out the high speed problem with the other engine that you mentioned in another thread recently?

[CNew 403]

David,

   Thanks - Yes, I did the air test with the carb and it only passed air when pressing the button so I think that seems to work. I cleaned the tank, added new line inside and cleaned the pick-up filter and added a small in-line filter as well so it should be ok. Looks like I may be down to the seals or reed valve, hadn’t thought of that one.

 

I’m hoping to get back to the other engine that was running at high speed this weekend and hopefully figure something out on it. 

 

Thank you for all the great advice and suggestions, always very much appreciate it!

 

Clint

[Wallfish 691]

22 hours ago, Webhead said:

Also, sometimes if you just walk away from them for a while,

BEFORE smashing them with a hammer!

The best way to learn in my opinion is to just keep at it. You'll figure out what works and what doesn't but it can easily get frustrating at times.

[CNew 403]

22 hours ago, factory said:

P.S. Did you sort out the high speed problem with the other engine that you mentioned in another thread recently?

I played around with the other engine a little bit today and I think it’s running better now. I used a Q-tip pushed through the throttle cable holes on the side of the carb to allow me to toggle the throttle and get a little better control on the speed, especially for the lower/idle speed. If I can find a spare throttle cable from an O&R chainsaw or something I may try to rig it up as part of the engine display/test stand.

[factory 483]

A spare throttle cable could be used if you want a slower running display engine.

 

Was the vane/throttle moving by itself? If not check the throttle butterfly shaft isn't gummed up, or maybe the spring requires too much force to close the throttle in normal operation (I seem to remember you mentioning the retaining wire was missing from the spring, so it could have been altered/bodged by the last owner).

 

By the way O&R did sell an external throttle control, I just haven't found one or an engine fitted with one yet for my collection.

 

 

David

[CNew 403]

Everything checks out, vane and throttle are moving freely. I was able to fix the spring so it’s now in good working order as well.

 

Nice find on the A-50 throttle cable assembly - wish I could find one for $1.00

[Wallfish 691]

IMO if you are going for a running display engine to demonstrate, go FWO. Those little things scream at high rpm and it's quite a bit more exciting like that than a slow idling engine with momentary high rpm by controlling it! It's the first impression that's gets'em excited so instant full blast always works. just my $0.02 on it.

[CNew 403]

Good point John!  I’m still getting use to these little screamers - they’re so different from standard 4 cylinders so I’m still getting use to the high rpms. They seem like they want to explode

[K-TRON 24]

When my O&Rs fail to start easily I hookup my rubber tipped blowgun to the breather in the fuel tank. With the air regulated down to 10psi, I use the blowgun to push fuel right into the engine. Pull the plug, check that it is not hydrolocked from fuel, and start it. I run clear tygon fuel line so I can watch the air push fuel bubbles out of the line. The diaphragm in my Comet saw was totally dead so it required constant maintenance to keep it going. With the new diaphragms from John it should fix that. If your O&R has a primer, you wont have to do this, unless it too has a bad diaphragm. If that is the case, hold the primer down and use the method above. Cross your fingers and it may start, it is an O&R afterall.....

 

Chris

Edited April 1, 2019 by K-TRON

[CNew 403]

Thanks for the tip Chris!  I’ll have to try that sometime. 

 

Clint

[factory 483]

23 hours ago, CNew said:

I’m still getting use to the high rpms. They seem like they want to explode

 

They go even faster if the vane falls out, had that problem with my first engine (the vane was bent the wrong way).

 

David

[Wallfish 691]

7 hours ago, factory said:

 

They go even faster if the vane falls out, had that problem with my first engine (the vane was bent the wrong way).

 

David

See, David got excited and impressed so much by these little screamers at high rpm he's now the O&R guru.

 

[CNew 403]

Haaa- those are great!

 

David, when the vane fell out did the engine exceed the max rpm?

[factory 483]

17 hours ago, Wallfish said:

See, David got excited and impressed so much by these little screamers at high rpm he's now the O&R guru.

 

 

They just don't scream for long enough though, high RPM's soon drain the tank.

 

And yes it did go way way past the normal maximum speed with the vane dislodged out of the carb from the vibrations, it took a few more high speed runs to find the cause. The RC modellers almost always chucked the vane away to achieve a higher RPM too.

 

Here are a couple of pictures of the bent governor vane, that were posted on the old forum.

Bent governor vane

 

Repaired governor vane

 

David

[CNew 403]

Wow, that’s major!  Thankfully I haven’t seen any significantly bent vanes yet on any of

my engines. I’ll keep an eye out for it though...

[factory 483]

That one is actually an all aluminium governor vane from a .85HP engine and because it was my first O&R I had nothing to compare it to at the time, but I soon found help on the old forum.

 

David