Doubles trouble....

Discussion in 'Lawn Mowing' started by FrankenScagMachines, May 9, 2002.

  1. FrankenScagMachines

    FrankenScagMachines LawnSite Platinum Member
    from IN
    Messages: 4,739

    I'm having trouble.... double trouble....
    I put on doubles on our 1993 Wheel Horse 520H garden tractor. It has a 48" side discharge deck. The doubles are all medium lift blades, no gators or extra high lifts. It has a 20hp twin Onan engine and the doubles are not helping any at all like they should. They aren't helping chop up the clippings any more than singles, they are seemingly causing more discharge than regulars maybe due to extra lift, and they're causing a ton of blowout around the deck, which is maybe 4 1/2" deep and about 4" deep in front. It's causing so much blowout that it's getting in my face and eyes even with sunglasses and a bunch is getting stuck to the flywheel shroud screen (air cooled engine) and I have to stop every couple rows and clean it off, and once it got so bad (before I realized it was sticking) that the overheat light came on. Plus, my stripes are not coming out as nicely as with singles. I'm really DISSATISFIED with doubles.. anyone else having these troubles with them? I am running the engine about 3500 - 3700 rpms approx, no less than 3500. Last week I didn't have to clean off the shroud screen but once or twice, for 2 acres, and no **** got in my face, and it left great stripes and cut. I am really upset by this (obviously) and that was just the back yard. I still had to double cut to get acceptable results and like i said, the stripes were not that good. I am going to take them off before doing the rest of the yard so I can compare the two.... What am I doing wrong, if anything? Soon i'm getting Gator blades for this and I'll see if they are as good as they claim, but as for double blades on this mower and tractor setup, they are as good as junk to me! I'm through with them until I get another mower.
  2. trimmasters

    trimmasters LawnSite Senior Member
    Messages: 264

    Perhaps the deck on a consumer grade mower is not as capable of handeling double blades as a commercal mower? from what i remember the deck on our old wheel horse was not near as deep or have the same baffle system as on my exmark.
  3. Bunton Guy

    Bunton Guy LawnSite Bronze Member
    Messages: 1,927

    Nope I tried the same thing on my bunton hydro 16hp last week...hated it SAME results to the dot as listed above. ****** stripes to much clippings....looked like it was even cutting it shorter no fun no good.
  4. gravedigger5

    gravedigger5 LawnSite Senior Member
    Messages: 505

    I just started using doubles on my 48" Howard Price. Both sets are high lift. No blow out, shreds good, and my decent stripes got better. Check your pitch front to back, should be about 1/4" lower in front (blade height). Don't know if that will help with blowout, but should help stripe better. Goodluck, Marc

    Are We Having Fun Yet???
  5. FrankenScagMachines

    FrankenScagMachines LawnSite Platinum Member
    from IN
    Messages: 4,739

    I already checked the pitch. It's perfect. BuntonGuy, you know what I'm talking about then.... this deck is built like a tank - same as the tractor, and it has a good blade speed and good cut with single blades. I took off the doubles to cut the rest (front yard) and it worked great. These are getting worn enough to skip a tad between blades and don't hold a sharp edge and are hard to sharpen so that's why i'm getting gators and I wanted to try them anyway. Oh yea, it will cut alittle lower with doubles because you have come down a tad lower (blade thickness) because of the second blade. I lifted the deck a tad to compensate for this though. Apparently not all machines are like this because i've heard alot of good about them. The engine did load down alittle even with a 2.4" per horsepower ratio. It doesn't even notice the single blades and it cuts and stripes great this way. Well so much for that. I had tried them before and had same results (on same mower) well thought today I'd give it another try... for now i'll stick to singles on this mower. I'll still give doubles a shot on different mowers in the future but this tractor 'weren't meant for them' .. I have messed around with pitch on mowers to see if it really does help stripes and have not noticed much difference, if any. Maybe it's just our type of grass. If blowout was the only problem, i'd maybe make a flap but i'm still disgusted with the rest!
  6. MikeLT1Z28

    MikeLT1Z28 LawnSite Bronze Member
    Messages: 1,732

    never tried em but i hear exmark's with a mulch kit don't like them. 65hoss has an encore he mostly uses for chopping leaves before running the lazer over them to pick them up and it runs doubles. does good on grass and leaves.

    bunton guy, i'm not a moderator and it's no big deal to me personally, but there are some younger folks here that post and read. any way you can *** out some of that word? like i said, just sort of keeps it clean for the young and professional.
  7. strickdad

    strickdad LawnSite Senior Member
    Messages: 544

    the first question is, did you guys leave a spacer out when you added the other blade ?? if you didnt it will put the blade down lower in the deck.. this will cause blow out, bad stripes, etc.. next thing is (bushhog) you may not have enough blade tip speed to run doubles, alot of tractor type mowers dont.. (bunton) you may not have enough h.p. to be running doubles.. does it pull the motor down?? blades not turning as fast?? anyway it all comes down to blade tip speed. if you aint got it you want benefit from running doubles. you also need the h.p. to keep the blade tip speed up when in high or thick grass..
  8. SLS

    SLS LawnSite Bronze Member
    from Mars
    Messages: 1,540 beat me to it. :)

    It is ALL about blade tip speed...which garden tractors don't have. I doubt that the Wheel Horse gets anywhere near 18,500 fps. Even with the engine turning 3800 rpm one must take into consideration the effect that the deck pulleys circumferance [sp?] have on the reduction ratio vs. rate of speed. And the blade to baffle placement is also critical to vacuum and blowout issues.

    About doubles cutting lower:

    Exmark blades are 1/4 inch thick so one must compensate the deck heigth adjustment or you will be cutting 1/4 inch lowere than you think you are. Add a spacer between the blades and it really gets lower.
  9. FrankenScagMachines

    FrankenScagMachines LawnSite Platinum Member
    from IN
    Messages: 4,739

    it doesn't have any spacers to start with. As mentioned, it's 20hp to 48" and I know that's plenty of power because some GT's [used to] (in early 90's) came with 12hp and a 48" deck was optional. Not recommended, optional. But that's beside the point. This thing does have a high blade speed (no not as much as a commercial mower) and two pulleys to select to put the belt in. I put it on the bigger pulley on the motor which is what they say to use so that it has a faster speed. This thing cuts fine at about 5 mph but any faster and it starts streaking between blades because the blades are worn so bad. Yes, all the belts are tight.
  10. 65hoss

    65hoss LawnSite Fanatic
    Messages: 6,360

    Stickdad is correct.

    Some mowers can not handle doubles. Just a fact. If its cutting lower its because you added a blade to the bottom and it dropped the cutting height down. Also, since you don't have spacers, by dropping that blade down, you created the blowout. That is mostly why your having a wall of debris all over you and the mower.

    Comes down to this. Not all mowers are the same. What works on 1 doesn't always work on the other. Trial and error. Just like blade combos on doubles. The combo I like may be different on another brand mower. Sounds like you've tried double on the tractor and it doesn't like them. Get a set of gator blades and try single gators. That should help chop up the clippings better without losing the cut quality.

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