New HF 6.5 Start up back firing flames

[rgvkid]

I Mounted my Brand new 6.5hp Harbor Freight engine on a rack to do a start up and leave it running for a bit to break it in. I added 10w-30 oil and 89 Oct. gas. Started up right after 2nd pull but its pretty choppy at low idle and smoothens out at high. But it pops flames out of the exhaust and low and flames constant at high throttle. It was only on for 2 min. before i shut it down. Is this part of the break in process, is it just burning up oils in the cylinder from the manufacturing? When i shut it down, the inside of the exhaust was super Red Hot.

I'll post pics.

 

[Russ2251]

First off, no break in is required. Many new mowers, pressure washers, generators and compressors have no speed control and run at full throttle (3600 rpm) right out of the box and throughout there lives. Your engine is no different.
Flames could be result of operating in a darkened room. Most engines will throw a certain amount of flames.
From your description, however, sounds like a lean condition. Back out low speed mixture screw until engine smooths out.

 

[jr dragster T]

Doesnt look too normall for a stock muffled engine to throw flames like that. If it was only a pop when decelerating wouldnt be a probelem but a constant flame thrower is kind of odd. I know at night my 6.5 clone with a header would shoot flame's on hard accel and decelerating.

 

[ZnsaneRyder]

From your description, however, sounds like a lean condition. Back out low speed mixture screw until engine smooths out.

I agree, regardless of what the manual says not to do, ignore that, and adjust the screw like Russ says. I had to adjust mine a few times to get better idle and more torque at low RPM.

BTW, that's really odd that one of those engines new out of the box idles or runs funny. Usually they run great when first started.

I get flames and backfiring on my 6.5 only if I redline it too much without a load, and the valves float and rattle loudly, so you can't miss it. Maybe you are running the RPM's a bit high I guess? Does it still have the governor on it?

I'll admit, a glowing exhaust isn't usually normal with these engines. Keep an eye on it in case you have to return it.

 

[rgvkid]

I exchanged the flaming 6.5 for a new one and it started up great with no flames. The throttle lever is really tight but its going to be elliminated once i build the pushe trailer setup that te engine will mount on. The other motor definitly had something wrong with it and i realized now that the other motor wasn't wrapped in a plastic bag like this one was in the box. Maybe it was a return.

Thanks for your help everyone.

 

[kibble]

Awww dude, why did you return it? You accomplished, without even trying, to get flames shooting out of your exhaust! Something some others on here were trying to do....

Ha ha, I hope you know I'm joking. Yeah, that wasn't normal.

 

[ZnsaneRyder]

I exchanged the flaming 6.5 for a new one and it started up great with no flames. The throttle lever is really tight but its going to be elliminated once i build the pushe trailer setup that te engine will mount on. The other motor definitly had something wrong with it and i realized now that the other motor wasn't wrapped in a plastic bag like this one was in the box. Maybe it was a return.

Thanks for your help everyone.

SWEET!!! Glad to read the good news rgvkid!!!

 

[Kenny_McCormic]

Awww dude, why did you return it? You accomplished, without even trying, to get flames shooting out of your exhaust! Something some others on here were trying to do....

Ha ha, I hope you know I'm joking. Yeah, that wasn't normal.

All ya gotta do is jet it a little rich and put a spark plug(need to come up with power supply) in your exhaust tip.