RedMax 8001 warm restart issue

Valk

LawnSite Platinum Member
Location
KS
IFF my 3 yr old RM 8001 is sitting in the sun it has become a bit coldblooded upon restart from one lawn to the next requiring 4-6+ pulls to start (requiring choke by 3rd pull)...then it doesn't want to run at full throttle for literally at least 1-2+ minutes.

IFF it's sitting in the shade during my mow/trim time it will start right up and run at full throttle relatively quickly.

Normally, I would choke it upon first start of the day...and NOT need to choke it again until the next day as it would start right up on 1, sometimes 2 pulls ALL day.

What can I do to alleviate this situation other than trying to keep it in the shade?

Granted, I can get a lot of work done with this behemoth even at idle/off-idle...but it is what it is at this point. Air cleaner is clean...will try a new sparkplug soon.
 

MowerMedic77

LawnSite Bronze Member
Ok so I have read this post a couple of times now and I'm going to tell you how i would check this unit.

First visually inspect for wet/dirty/oily areas that would indicate a leak around the cylinder/carb/intake/crank seals/ case half. I test with a pressure and vac tool and block offs for the intake and exhaust but not likely something you will be able to do so visual inspection is the easiest recommendation for you.

Check compression and also inspect to scoring or wear on both sides of piston and cylinder(internal) Even units with good compression will not run good if scoring/ wear present below the piston ring(s)

Inspect pulse port in insulator block for blockages sometimes carbon or gasket material blocks the port.

Test tank/cap vent for proper operation, inspect fuel lines for cracks or pin holes, fuel filter should be new/clean and you may also want to tear down and inspect carb. In three years of hard use the gaskets in your carb are sure to be worn.

Let us know what you find....
 
OP
V

Valk

LawnSite Platinum Member
Location
KS
Thanks for the input. I'll be discussing this with my dealer as well when I pick up a new sparkplug today.

FWIW: I've used ethanol-free premium fuel with Stihl 100% synthetic 2-stroke oil for all of the last 2 years with no issues. Thus far this Spring I tried Echo's synthetic blend in 2 gallons and am about to finish it. I gotta say that this is the only thing I've done differently and will be going back to Stihl's synthetic fo sho.

I had used RedMax's synthetic 2-stroke oil the first year with no issues...but I had trouble finding it in bottles for 2 gallons worth. I was only finding it in bottles for 2.5 gallons...so I made the switch to Stihl.

I SURE want to think this bizarre issue is something simple like a need for a new gascap or a switch back to Stihl synthetic oil.

Once this blower gets past it's intermittant stumbling after sitting in the sun upon warmish restarts, it runs like it always has...which is very impressively.

Thanks again.
 

sjessen

LawnSite Fanatic
Location
Knoxville, Tn
My Redmax blowers do the same thing. What seems to be happening is the fuel tank pressurizes while sitting in the sun. I have seen the gas literally bubbling in the tank. What has worked for me is to open the gas cap and let off the pressure, then prime it a time or two and start. Depending on how hot the gas is the blower will usually start on the second pull.

I have resorted to setting the blower in the shade, usually under the side of the trailer or truck.

Hope that helps.
 
OP
V

Valk

LawnSite Platinum Member
Location
KS
My Redmax blowers do the same thing. What seems to be happening is the fuel tank pressurizes while sitting in the sun. I have seen the gas literally bubbling in the tank. What has worked for me is to open the gas cap and let off the pressure, then prime it a time or two and start. Depending on how hot the gas is the blower will usually start on the second pull.

I have resorted to setting the blower in the shade, usually under the side of the trailer or truck.

Hope that helps.
WOW. I was hoping I wasn't imagining ghosts!

I'll have to try ALL this. I did try removing/reinstalling the gascap during this escapade...but it did no good. Honestly, I've not hardly ever chose to use the primer as my starting methods have been successful w/o using it.

A new NGK spark plug did nothing to remedy this situation...but it's (usually!?) nice to know you've got a new properly gapped plug in there.


Mower Medic 77 wrote: "Test tank/cap vent for proper operation."

I'll next replace the gas cap. There are some scuff marks on it from over the years. I can see where a mild leak at the cap could potentially interfere w/ fuel flow.

This RedMax HBZ 8001 has been a SUPERB blower...just hoping there's more years in it. I can't say enough about it's power.

Thanks guys! Will post back...so's we can all learn.
 

sjessen

LawnSite Fanatic
Location
Knoxville, Tn
Valk,

If the gas in the tank is really warm you may have to let it cool a bit so that the tank does not repressurize.

Btw, I have two brand new 8500's and they do the same thing. Pretty sure it is a fuel related issue. Seems the blowers vapor lock.

Best option is to try to keep the blowers and trimmers out of full sun, if possible.
 
OP
V

Valk

LawnSite Platinum Member
Location
KS
Well, it was in the upper 80s here in late March...wtf! I've not encountered these kinds of issues in the previous Summer's hot weather.
It has since cooled off quite a bit...but as soon as it warms up again, I'll try all the above advice.

This blower will run like usual...but only after 2-3 min minimum of not wanting to run at full revs ALL signaled by encountering a difficult restart.
Thanks guys.
 

sjessen

LawnSite Fanatic
Location
Knoxville, Tn
Well, it was in the upper 80s here in late March...wtf! I've not encountered these kinds of issues in the previous Summer's hot weather.
It has since cooled off quite a bit...but as soon as it warms up again, I'll try all the above advice.

This blower will run like usual...but only after 2-3 min minimum of not wanting to run at full revs ALL signaled by encountering a difficult restart.
Thanks guys.
Mine do the same exact things. Wondering if winter vs. summer gas blends make a difference.
 

2stroked

LawnSite Senior Member
Location
north carolina
The only thing that I believe could cause it would be the fuel in the tank heating up in the sun. I have a stihl weed eater that used to do the same thing, I would open the tank up and then give it a few primes and maybe half choke and it would fire up on the first or second pull.
 
OP
V

Valk

LawnSite Platinum Member
Location
KS
Mine do the same exact things. Wondering if winter vs. summer gas blends make a difference.
Interesting hypothesis as we might still very well be getting the Winter fuel blends.
As stated, I run only 91 octane ethanol-free gas and am back to using Stihl HP Ultra, fwiw.
 

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