Fixing A Redmax EBZ8500 Backpack Blower That Won't Start 

All of my rotations around the Sun, I’ve never seen such a thorough explanation of how an engine work. You just taught me a lot. I really appreciate you making this video. Thank you.

The one thing you didn't check was the kill switch circuit. It might have had some little piece of crud partially grounding it out (as indicated by the inconsistent spark in the beginning) that eventually broke loose without you knowing while you were fooling around with it, allowing it to start later

4:18 the reason your gauge showed lower compression than expected is because you used the attachment for the compression tester for the smaller spark plug hole. You need the Schrader valve to be at the absolute end of the tester, or else the extra volume will reduce the compression, even if it was just a little bit. I've struggled with this in the past before I realized this

Great catch. I guess I have a couple more things to add to the "doesn't start" diagnosis aside from fuel, compression and spark. lol You are a real patient guy. Don't think I would have caught that. Thanks for sharing.

I hope your friend appreciates all the work you did on his blower.!

I love turning on my RU-vid feed and finding more and more videos from this channel! I remember taking computer maintenance classes back when I was in community college and having tests where we will be presented with a computer that had some issue and we had to figure out why it was not working, I enjoy watching your videos and following along as you diagnose each mystery and I try to keep up with what I have learned so I can try to anticipate what will you try next. I am not at the point yet where I can foretell your every move but I am still learning 🙂

Not for the issue you had, but as an FYI for later. These Redmax blowers, it’s very common for both the cylinder head and intake manifold bolts (4) to loosen or check as loose. When either the intake manifold or head gasket leak, if will cause various mysterious running issues. As a preventive measure when new, a good idea would be to put a white paint mark across the bolts and manifold and bolts and cylinder base, so with a quick visual inspection you can see if the bolts have loosened. However, the assemblies/gaskets may compress over time and thus the tension is released and although the bolt hasn’t turned, it would check loose when you tried tightening it. So, it still may be advisable to torque check these bolts periodically. Some other ideas would be blue thread locker, nordlock wedge lock washers (add 2mm to assembled height, may need longer bolt to maintain thread engagement), and lastly, safety wire bolt pairs to each other if you’re good with that sort of thing.

I had something similar happen. Got a brand new ebz7500 at work. Was loving life, breaking it in and all that. Got low on gas 1st tank went to grab some and came back. Blower died but didn’t run out of fuel. The ignition coil failed within the 1st couple hours of use according to the shop. I didn’t get the chance finish breaking it in…. Boss gave me another new blower the next day and that one has been a champ for 3 seasons. Was super weird to say the least.

Good findings. Ebz8050 Takes 3 primer pumps, put on choke and then 3 good pulls and it always starts on the 3rd pull. You can take it off choke as soon as it starts. It’s been a great blower. Put on a eBay/China $12 carb on it last year after 6-7 years of ownership with no other issues. I’d buy one again.

I have worked on one of these and they are a BEAST ! Made some videos because it would come back every few months with new issues - carbs, fuel filters , coil etc. powerful does not quite cover the output!

We learned something new this video, i suggest adding this to the diagnostic list when it comes to checking the ignition system, checking the air gap between the flywheel magnet and ignition coil will play a huge role when checking for spark, that helped me when i was working on starting the Husqvarna 252RX to check that everything was working as it should be 😄

Great diagnosing vid mate, Ive done plenty of miles with on of these. They can be a real headache sometimes. As it was needed first thing every morning hot or cold weather, it tested your steel now and then. Cheers

This is common for red max blowers. The ignition coil is either faulty or not adjusted properly.

I’ve been running redmax 7500 and the 8560s for 6 years the best blower I have ever used all them start with in 3 pulls every time just got 2 new ones yesterday

Neon spark testers are only a quick test, you really need a spark gap tester to see how far the spark will jump. Sometimes the neon testers will show a small glow and the spark is not good enough to start the engine. I see this sometimes on Honda's that I repair. Those are great blowers, and thanks for the video.

I would mix up a fresh batch of 2 stroke fuel which I had to do With a stubborn customers Ryobi line trimmer & he was adamant that he put the right amount of oil into the fuel tank of his 2 stroke Ryobi trimmer about 20 years ago which wouldn't Start. I tipped his fuel out & ran the workshops fuel in it about 20 years ago & it started & ran. He had taken it elsewhere in town & they said the same thing !

Great video, that's a nice blower, I would probably just do what you did and modify the starting procedure to prevent flooding.

I have two..when it works it's a beast..and when it doesn't time to tear it down just like you did..only problem I've ever had was fuel related..otherwise it's a good blower..

Learnt how to start the engine by using the drill today.

I think the spark checking tools can be very useful, but at the same time, i like to see the spark right from the plug and just see how much and how good of spark there is. Shame we didn't get a before video of it and then the after. Great work, for sure would leave it how it is. I got a free weed eater on the side of the road, thing started 3 pulls...no issues. Well theres that, HOWEVER, i also have a residential grade Sthil weed eater which is a PAIN to start, and is cold blooded. Some might throw that away just for how it starts.

If this machine was that new I would have returned it. If not then the customer did what he/she should have done and you fixed it. What a puzzle this one was. If it is that hard to work on I probably would not purchase one unless they are all about the same. Great job on the diagnosis and repair. Thanks for the video's.

Good job once again, you sure do have a lots of friends 😄I’m still trying to find a carb for an old chain saw project I started about 6 months ago 😂Mike from Quebec 👍🏻

Excellent video on the EBZ8500. Thanks.

Those red max blowers are awesome 👏

Thanks for tearing this unit down. I've had this model a few years now. Awesomeness blower, when it's working correctly. That's the problem. Always seems to be something. Recently I'm dealing with it bogging down on full throttle. (AGAIN) I've changed the plug and fuel filter and worked well for a session. Next time out it bogged down again. I changed the fuel and will try it again today. So frustrating.

Thank you so much! I have been struggling figuring out why this chainsaw I got doesn’t try to start. It has spark, compression, gas, and proper timing. I have a feeling it was the magneto distance like that blower, will try!

very good job congratulations

🤣 Now THAT was funny! “I didn’t even mind that the noise hurt my ears”.

For a while, I was thinking that there was something wrong with the kill switch. I was thinking that the manufacturer had a faulty kill switch that was preventing the blower to start. Good detective work on your part. 🤔🤔🤔🤔👍🏿

Very odd that air gap was like that on a new blower like that . But very glad you were able to get it to run

wow it really gave you a hard time didnt it. Fun to see some of the bigger commercial equipment on the channel, I have heard a lot of good things about redmax and their equipment.

Boy, what a ride. The moment you pulled the rope while testing the spark plug, I thought about the coil.

If it starts, that's good enough for me. The 8 horse I/C on the Roof won't need choking even when cold if it's just been a few days. My pal at his saw shop clued me in on that one. That model Briggs is just that way. It starts on the last charge it got when the ignition was shut off. And the Echo fired on the 2nd pull instead of 3rd! Maybe it'll start cranking itself! Thanks and Blessings!

These are great Blowers. I own 4 of the 8500 and 2 of the 8550. Mine don't seem to flood as easy as this one does not sure if it makes a difference all mine are left hand throttle. Also the oil in the air intake pipe is normal. We always have to choke all of mine to get them started it doesn't matter if the engine is hot or cold. One more thing always start them with the throttle in the idle position.

I have 2 redmax chainsaws and a redmax weedeater all are very easy flood the engine if you done start it correctly thanks for the video

Good video again thanks 🙏

Just had exactly the same problem with a post hole borer. Looks like the same carb also. Did everything you did and couldn't really see any problems. But while it was out and stripped, I ultrasonically cleaned the carb and reassembled it. Did the tank also. Put new fuel mix in it and with a prime it started 4th pull. So perhaps I just couldn't see fine dirt particles in the carb??

I really like red max, i think its. A good starting machine brand for anyone that wantsa. Good bang for the buck, my dad tho, he doesn’t like back pack blowers, i mean their powerful n all but he just settles for a hand held

My two new toys is a hedge trimmer and a Weedwhacker and right from the box they both needed carb Justments surprise there

Great video!

I have a two copies of this machine or a rebranded version & i can tell you this much, mine won’t start with wide open throttle, to start i follow the manufacturer’s guide which i s to apply full choke no throttle, pull start until the engine starts & runs & when the engine starts to stumble, open the choke to fully open & the engine continues running, after a minute of warm up i can apply full throttle. I don’t own a single two stroke engine that requires any throttle to start & i own 8 different machines with various sized engines. Last year i had one of my Honda engined Toro Hoverpros that would run for a few minutes then die, it would restart each time but die again. Turned out it was the spark plug which was a resistance type plug, the resistor was failing & cutting out. A new plug immediately fixed the issue. A resistor plug usually has an R in the part number.

I've had this problem with an 8550 redmax. I've had this problem on 2 blowers. The fix I went back to Echo after using redmax for 23 years . I'm no longer confident with redmax

Great video

I had a lawn boy throw me in for a loop once. Had everything to run. Coil plug carb swaps nothing worked until I looked in the exhaust and realized the piston rings moved and lined up to cause it not to run. Was a real head scratcher

My boss sells redmax products. The 8500 in my opinion, the best blower on the market. 2 things over the years that were a problem. 1. The bolts on the fan would egg out causing fan wobble. They recalled it. 2. Coils were intermittent. Similar to the start of this video. Also a recalled part as well. Sorry for the long comment lol.

I have a bunch of these blowers and sometimes the wires get caught and cut to the kill switch or the connections come loose. Always worth a check too. I have never had an issue with flooding though

Anytime an engine floods beyond its normal choke point, you should check the air filter for any obstruction. If that's good, the next thing to check is your high and low fuel rate metering screws could be out of adjustment and letting in too much fuel during normal ops.

Wow! 😳That was the only problem, it was the coil wasn’t set correctly to the flywheel lol. Anyway I have that exact same ebz8500 blower that’s hip mounted not tube, and it’s probably the best backpack blowers I’ve ever owned. I got mine used for $250 back in May of 2020 and sure has been great! It was used as a residential landscaper before I bought it. Now it’s 9 years old and the only things I had to do to it was change the air filter and the fuel lines, that’s it. No carb problems yet. And plus I repainted it, got new tubes and a decal for the air filter cover back in 2020 as well to make it look like a brand new 9 year old blower.😉👍

Great video. We’ve got one that looks like a brother to the one in your video. WE have the same issue. Brand new and wont start. Sounds like it coughs but never fires up. I’ll have to check what you did. Thanks.

As someone who works in gopeds there is a model called a geo sport. It has a double stack carb like that and they are very finicky. I finally just decided to replace manifold with a single stack manifold. Also that looks a lot like a Zenoah engine.

Love your vid.

I have worked on one of these and they can be difficult!! Too powerful for me when running properly. Great to clean out your flowerbeds!!

Yet again another great video!! I love how you went through every diagnostic step to find the issue, that's why I love your channel. You are very detailed in your vids. Me I personally would have done the same thing for starting it. If I can figure out a way to make it work then that's what I'd go with. Keep up the awesome work. Thank you again for your content

this video was great but i have a question. i have a stihl fs86 line trimmer that runs very well but after 4 mins of use it starts to smoke and when the engine goes back to idle the engine has a little cough. i bought this line trimmer second hand and fixed it up all it needed was some attention in the carb. once i started the trimmer up it ran well but accidentally touched the aluminium housing for the piston for less than a second and burned off a lot of skin on my knuckle. at this stage i only ran the trimmer for about 30 secs. i noticed that the spark plug boot was hot after 4 mins of run. but before i touched the carb the engine was covered in dirt as there was a fuel leak in the tank. i sprayed some degreaser on the engine block and that might be the cause of the smoke but it gets really hot. i also made sure that i tuned the carb to be rich. can u pls help me as this trimmer has 2hp and i need this trimmer as ive got a fare bit of land to maintain

when i worked for my old lawn care job, i primed my 8500 5 times, choked it, i left the throttle on idle or maybe a 1/3 of the way open if it was cold, and then pulled it. And usually but not all the time it would start right up within 3-5 pulls.

i have an echo backpack blower that i am working on and we just replaced the ignition coil with s brand new one. however it had no spark no matter where the killswitch is turned to

Worked as a landscaper some years and in the workshed when picking up a tool such as a chainsaw, blower or trimmer, the older guys would tell you " aha, you have the nr.354 so you need to prime, 1 pull full choke, 2 dry, 1 at 1/2choke - starts".

I'd set it up for electric start using a drill to spin it at speed, like one of my friends did with his mower.

I once used jb weld to block off full choke on a cheap weed eater because I was staying away and kids were using it Crazy but worked for several years

Yeah I got two new toys today and I flooded them both on my first attempt to surprise the coil was out of adjustment that does that does happen though

In regards to the flooding issue on start up, it looked to me that you set the throttle hold lever “cruise control” well above the 1/3 throttle “high idle” as prescribed in the operators manual for starting. Too much starting throttle was confirmed for me when you did actually get the engine started and it revved up well above What I know start up high idle warm up rpm to sound like on my own husq 570.

Nice ...the most diagnostic work....I woulda thought an inconsistent spark plug

Another YT ER's 2nd test after fuel is pull fuel filter off and test if the line to needle holds a vacuum if it doesn't then isolate the line by blocking other side to recheck. You probably know of this but like me haven't got a mityvac yet 😉👍

ive tried the drill trick to start my 4hp craftsman mower but it wont spin it. I have a dewalt 18v drill and an 18v fuel milwaukee impact wrench AND driver and none them wants to spin that craftsman. I have to pull it with the rope and its a pain. What drill are you guys using to spin these motors?

That’s would be my decision as well. As long as you can start it, that’s good enough for me.

So I have question, it might sound dumb. I was given as a gift a back pack leaf blower, it's a Chinese made blower that the manual says 2014. It's brand new, my question is it calls for 25:1 to 30:1 will it hurt if I run a pre mixed fuel of 40:1? Or should I use what the manufacturer calls for? Thank you for any advice you give or have given me

The air gap was the problem All the time but you did All the tests you needed to do to find out the problem

Hey. This was a good one! I’m sure it was Frustrating to say the least. I’m not familiar with those carbs. Are there any hidden adjustments on it so you could lean it out a bit for start up? To answer your question, if it was my own machine I would also just run with it once I figured out the sequence. Cheers

I recommend the SUNOCO non ethanol pump gas ⛽ keep up the good work man

That weak spark when you first tried starting it would have been my first path of investigation. I would have checked the kill switch first and then looked at the coil next. Resetting the air gap seemed to help.

A great spark tester is a large rubber insulated spring loaded clamp with a foot long wire attached to it and a smaller spring loaded clamp on the other end of the wire , ( just like the battery charger clamps ) take spark plug out then clamp big clamp onto spark plug and smaller clamp directly onto a metal ground aka engine block or good point of ground " pull cord watch for spark ,, also make sure you have a KNOWN good spark plug to test with ! Don't forget the ignition kill switch can be bad or have high resistance causing weak spark also ! And yes those almost new ignition modules can and do go bad just like that ! My Husqvarna handheld blower worked great one day next day bad ignition module !

I agree. If I know how to start it, I probably would not investigate further.

Is it a problem if I start my sthil fs 120 grass trimmer on full choke and when it tryes to shut off I turn the choke off and it runs.

I have a Poulan Pro blower. It was always running great. Then I ran out of gas. When I mixed a new batch of oil gas mixture it ran for a while then quite. Is my oil to gas ratio off. Or maybe the oil blend, brand (Pro select) was not good for my blower? Can you help?? It will start then quite.

Have you tried putting a new spark plug? I have had some bad experience with those small thread spark plugs which can look good but still would foul and get wet pretty easy

Sounds like a good running blower,don't know if it would be harder to start when cold though

I got one for you. I own a STIHL BR380 blower. Even though it’s 11 years old the hours are low. I only use non ethanol gas and synthetic oil. Last week after full throttle use of about 30 minutes it lost power (rpm’s dropped). I took off the cruise control and it idles fine. Shut it off and it starts fine but will not rev up to high rpm. Once cold I start it up and it does the same thing. Only difference is it only takes 5 minutes to act up now. I have done the following. Cleaned the spark arrestor, replaced the spark plug, air filter, fuel filter, carburetor (OEM), ignition coil, and fuel lines. Compression is 127 (checked it right after it lost RPM). I also removed the filler cap thinking the vent was clogged. No change. Spark plug tip looks normal. Once RPM’s dropped I sprayed starter fluid into the intake and it still didn’t accelerate. It has me buffaloed. Any thoughts. I know I can buy a new one but the new ones like this are 2.5 lbs heavier and I’m like you, I want to find the problem. Sure would appreciate some help!

I always hold the throttle wide open while pulling on choke no more than 2 times and then open choke and hold down throttle and pull , keeps it from flooding

What cause my trimmer to bog down on when i rev the engine

I’d also be looking at the reed valve (assuming it has one) since some fuel was in the intake boot…

Did you adjust the carburetor adjustment screws?

I have a red max blower the same model you worked on and my issue is it won't take full throttle It will bog down when given full throttle. I have checked everything you did on the one you worked on Any other suggestions

Unless I missed it you didn't mention any thing about the fuel or did you know the freshness/age?

It almost acts like a carb with a stuck open needle n just dumps fuel into the intake. Maybe that's what's happening when priming. Did you try starting it with the trigger pulled to give it max air flow n no choke after priming?

big job but a great video

I have the 8500 and it almost always starts on the third pull. I never Prime it either. When it’s cold I give it about 10 seconds before I throttle it up

I'm having the same problem with my Stihl FS 250 trimmer when cold it start up and idle fine but once the engine is heated and I cut off to refuel I can't get it to start back

I have actually used one of these things before, but I sure didn’t enjoy it. These things are really heavy and the shoulder straps are cheap and uncomfortable. After almost 40 minutes of using it I had to take a break because my back was killing me at that point. That is the main reason why I prefer handhelds or walk behind blowers to these things

I have a similar blower...and mine likes to be started with the throttle wide open.

I've had coils still produce a spark but be bad. I had a saw push me to my limit of sanity and it turned out to be a factory new wire on the coil that was crimped to hard and was cut through but looked fine. The saw still ran but like it had an air leak. It's annoying because you have to check the gas,carb,spark,exhaust, gap, and timing several times before you can finally deduce the coil is shot has an issue or is shot. That blower is way to hard to start I'd be adjusting that carb and possibly even the airflow if that didn't work.

I would check the needle in the carb with a mity vac

If I run my Homelite trimmer on full choke it runs fine. It runs perfect on idle but will die on throttle likes it's supposed to.

My recommendation: Buy the Stihl BR 800...better harness, side pull start , lots of power and easy to start!

If you remember you said the spark looked inconsistent when you first checked it. That would have made me dive into spark as the problem and reset the air gap as a first test.

That is common of when it gets hot coil shorts out

Yeah I'd do it like you did I'd try and see how to start it and then see what to do leave it or replace it

the leaf blower has a hard life since no one knows how to kick in the piston rings and stuff so they blast the hell out of it and when the piston and rings are gone they are like oh its toasted time to get a new one.

Would a vacuum check find that leak?

I don't know if I would buy one like that if it was prone to flooding that easily and I'd probably return it if I did , it seems like the carburetor is not working properly when choked you should only use half choke all the time no full choke on it , I think the manufacturer cheaped out on the carb if it was a quality carburetor it would work full choke , half choke and wide open basically fully functional carb , also the adjustment on the ignition coil could have been from it not being tighten properly from the factory or loosen when running and it moved when it was set down (if it was set down a little hard) and thrown the timing or spark strength off making it not start but only speculating what could of happened

Runs mint but I have to use a starting aid