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Max-mix PMS thumbscrew (thought you should know)

17 posts from 5 voices
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  1. Tucci641

    Have you ever learned a valuable lesson that if only you could share it you would somehow feel it may have been worth it.
    I purchased the PMS thumbscrews from Maxair Engineering for my 1100 Vstar. Heard em mentioned and the reviews were convincing so you spent the $35 and you bought em. As soon as I put them in I could tell they couldnt be right because the idle was emediately rough. In your head you figured, nahh it cant be the screws, they were mentioned on the forum and the reviews were favorable. Only to learn after several hundred miles it was the screws and if only I was warned. The tapper of the screw is different enough that you will have a rough enough idle to suspect there was either a jetting problem or perhaps the carb's were out of sync? I wont be able to put this lesson to rest until I warn everyone not to waste your money on them unless you want to torment yourself as I did.
    So there you go, try a different company or use the factory screws as I did...everyone is warned and now I am moving on...or am I? perhaps I need to rant a bit longer in other venues...perhaps I shall.

  2. bkman

    This sounds like something you should be posting on the Maxair forum - did you contact them? I only ask because they are usually pretty good about replacment / refunding for defective parts.

  3. Tucci641

    I did contact them actually, spoke to Max himself. Says I'm the only in thousands of sales that has a problem with the screws. That it must either be in the installation or possibly one of the screws being off. Asked me to send them back to him and he would possibly send me another set. If there is a possible problem with the screws what kinda luck is that, getting a set with a problem because it sure the hell can 't be in the install putting them in is as easy as zippin your fly!!
    Told him if it's in the install how is it when i put the factory screws back in everything smoothed out? Told him there was a distinct differance in the pitch of the needle from the factory. His response was the mixture screw is a basic design and the pitch has no bearing. The proof is in the pudding I told him, my control was the original mixture screw.
    Conclusion, I have none cant tell what was the culprid just that the idle wasnt right from the start and will do everything possible to the factory part before going to an after-market part in the future.

  4. quicgmicg

    I had the same experience with Max a few years ago......he's always right, even when he's wrong IMO. I'm just glad you got the bike running smoothly.

  5. Tucci641

    Wow Mick, almost believed him (Max) telling me he never has a problem with those screws and my situation is 'Ironic'. Wish I'd known the 'latest and greatest' screws from that outfit had an issue I would have never ever gave em a dime of my $. Reason why I had to sound out about my experience, crap like I went through will continue until someone calls em on their BS. Maybe I can get the ball rolling.....ride safe my friend

  6. 149lx

    mine work fine

  7. bkman

    mine work fine...

    I guess that was my thought - there are a lot of these things out there and its the first time I've ever heard anything like this. I am glad you got your bike running right - regardless of how you did so. I just have to wonder what other variables could be at play, other than defective parts. It seems to me that the probable cause would be a defect (which DOES happen sometimes).

  8. quicgmicg

    Wow Mick, almost believed him (Max) telling me he never...

    My issue wasn't with PM Screws but with an intake set up. I didn't like how I was treated and will never buy anything from them again. There are too many vendors out there that do a good job and supply great products to waste time with one that didn't.

    That's just my personal experience with them, I've heard their service has improved somewhat, but it can't be even close to the same level of service of the vendors I use now.

    Again, this is all just my opinion.....

    Stay warm up there Tucci641...we're dropping to 30* down here tomorrow night.....Dayyyyum!!

  9. Tucci641

    I know, we were gonna take the bikes out yesterday but the temp was in the lower 50's (hell nooo says the mrs!). I did take it out on Sat to see how my new setup behaved at highway speeds and it didnt even so much as hickup. Ran it all thru the throttle circuit to include 90plus speeds. No hesitation or stumble, I think I'm right where I want to be. Gonna give it a couple of hundred mile trips to see how the tailpipe and plugs look for color. 99Orton going to 162 mains at 800ft elevation has me scratching my head. I guess if the color indicates too lean I will go up a tad?

  10. quicgmicg

    It was mid 40's and too cold to work in the garage yesterday too. No NASCAR on so I bundled up and went out shooting 10 minutes from the house.

    Donn is not the only one that has jumped back and forth on jetting...the funny thing is that it really doesn't seem to make a lot of difference. I know Donn's fuel mileage doesn't even change. Go figure. It just shows how wide of range you can go on jetting and still have a bike that runs great.

    I'm just not sure how accurate color reading is going to be these days of alcohol enhanced fuels. It still might be best to put it on a gas analyzer to check the results.

  11. Tucci641

    Know what you mean, good to know there's a wide range on jetting...sniffin it almost always shows it running rich. The last time I did that It took me weeks to get it running the way it did before. 3 turns out on factory PMS seems to be the sweet spot on not needing the choke. I guess as long as the plugs arn't white ashy, I will prob leave it alone.

  12. HouseOPain

    Reading this post I recall in the Slone page mention of the differences in these screws over stock, and I gathered that the Max Mix screws will have a different setting requirement than stock. So if your stock screws were at 3 turns, and you try to set your Max Mix the same, your mix will be off.

    In case it applies, read here:

    The difference between the Stock PMS screw and the Old Style MaxMix screws are how fast they taper to a point. The old style MaxMix does it much faster, so if a stock PMS screws is 3 turns out the MaxMix is 1.5 turns out. New MaxMix screws have the same taper as stock, and should be adjusted that way.

    MaxMix NEW (since early 2008) have the same profile / slope as stock - so they are set the same as stock.
    3. MaxMix (Old) screws setting is measured from turning all the way in until LIGHTLY seated, then turn out to value given. MaxMix (old ones) screws have steeper slope and therefore require fewer turns.

  13. Tucci641

    Although they claim the 'newest' screws are just like the stock, if you hold them next to each you will emediately note the stock screw tapers quit noticably. Looking at the Max screw you can see that although the tip of the screw is the same, the remaining tip does not taper as much explaining why regardless of the turns, there remained a rough idle with the annoying pop towards the idle twist of the throttle. Max told me the taper has no bearing, that even though they claim its a newer screw, it is in fact the same screw only redesigned to appear different. The public gladly bought the new screws. This he stated after telling me its off the record. If you know anything about how a mixture screw works, you will agree it makes all the difference. I almost took pics of the two screws but thought it maniacle and talked myself out of it. He said he was outraged that his screw is being discussed in a forum. My reply was a quote from Edmond Burk... all that is required for Evil to prevail (or in this case ireputable manufacturers), is for good men to do nothing. Just can't let that be, just can't.

  14. 149lx

    I guess that was my thought - there are a...

    all it would take is dtpping the pms screw on the ground 1 time for it to not work properly. Waiting for my cams to get here

  15. Tucci641

    By the way Mick, 99, Fulltilt, I meant to ask you guys about the jet right next to the Pilot (not the main of course) its not addressed in the KB what is it and why does that stay stock?

  16. Tucci641

    342 good point, my garage has 1/4 rubber mat all over for just that kinda possibility, I've had a bike tip over and nothing happened to it couldn't even tell it tipped. The screws didn't get dropped while in my possession, but if they did at the MA warehouse its their responsibility to remove it from stock or risk somone going on a tyraid like I'm doing. I mentioned quality control with Max.

  17. quicgmicg

    By the way Mick, 99, Fulltilt, I meant to ask...

    Tucci641, I believe you're either talking about the pilot air bleed - which provides air to break up the mixture at idle...or the "starter jets" which push fuel into the carb when you move the enrichener (choke) lever. The choke doesn't just adds fuel.

    Obviously neither would need to be changed as they affect only a little air flow at idle or when you move the enrichener lever for a few seconds on cold start up.


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