[dave225]

I know this question gets asked a lot - and I have read & watched countless videos. I have removed, cleaned, rebuilt & replaced the carburetor, checked for spark, etc.

I had my snowblower (Honda HS35) working a few weeks ago. New carb, new gas. Worked fine. Here's what I'm seeing now:
-First of all. It took my some work to get it running, but it always started. Just needed some work to get it to idle right and keep running. I got that fixed with all the covers & trim removed.
-I used the snowblower once. All seemed to work fine, so I put the trim back on, and it no longer worked? (wtf!)
-When it first stopped working, I could spray carb cleaner or starting fluid into it and it would turn over & then conk out.
-Seemed like it wasn't getting gas, so it removed the carb & cleaned it. Not sure if the needle valve & float were out of place that whole time, but I noticed it wasn't moving freely, so I fixed it.
-Kept trying to start it and it wouldn't keep going.
-Over time (flooded) the plug was wet with gas & pretty black. I dried it & cleaned off the soot. Seemed to help, but still ran into issues.

Now:
-When I ground the plug, I can see blue spark. Doesn't necessarily mean it's enough spark, but it's sparking.
-When I spray (anything flammable) into the spark plug hole or into the carb, it doesn't even act like it's going to start.
--So I do think it's getting gas, but something else isn't right.

Can anyone give me some guidance on how to know whether the spark is adequate? Or what else could be the issue? It doesn't seem to be the easy answer this time. (But who knows? )

 

[bertsmobile]

Your problem sounds like a dirty carb idle jet , incorrectly adjusted choke and a fouled plug.
You clean plugs by burning off the fuel residue .
A plug might fire in open air but fail under cylinder compression .
As pressure rises so does the resistance thus the spark runs down the side of the plug & not through the gap.

 

[dave225]

Thank you for that explanation! I will try a new plug, properly gapped. (I think the idle jet is ok - I have cleaned, inspected, taken apart multiple times - although that might have been the problem earlier in my trials.)

 

[dave225]

Thank you for that explanation! I will try a new plug, properly gapped. (I think the idle jet is ok - I have cleaned, inspected, taken apart multiple times - although that might have been the problem earlier in my trials.)

Well, that didn't do it.

My latest guess is that perhaps water(snow) got into the cylinder? I'm going to tip it on end and see if anything comes out. Is there something I can spray in there that would dry it out?

 

[Scrubcadet10]

That's highly unlikely, unless it got in through the muffler somehow.

careful tipping it over, you may get a bunch of oil everywhere...
If the carb is in fact, clean, and spark is good, i would check the flywheel key. that aligns the flywheel to the crankshaft for proper ignition timing.

 

[dave225]

@bertsmobile was right - it is a choke/ idle issue. That's what it seemed like, but I have no explanation for why it was all of a sudden a problem. Choke wasn't all the way closed, which was fine before, but is now a problem. So that indicates to me that there's not enough fuel getting through the idle jet. (I have cleaned it out multiple times. ??) I actually cleaned up the original carb and put it back on - and it works better, but still idles too low.

I'll continue to struggle my way through this. May also be a leaky gasket between carb & engine, letting in air. ..

My other question (or maybe it's a clue) is that the venturi seems to do nothing at all. Idle speed is not affected by adjusting it in or out.

 

[Scrubcadet10]

does the carburetor have a idle stopper screw?
similar to what i've circled in red.

 

[dave225]

No - no way to adjust that way. But I did hook a cable up to the throttle so I can control it better. So I have tried a faster idle just by opening the throttle manually - it helps, but the engine still seems like it's way out of tune. (Also, it's no longer even starting - again, even with fuel shot in manually.)