1967 Loadstar "Big Onion"

Discussion in 'General IH Tech' started by TheCrazyFarmer, Jun 5, 2020.


  1. TheCrazyFarmer

    TheCrazyFarmer High Wheeler

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    Here is what the vacuum gauge read at idle.



    I don't know what kind of readings I need to take. Do I take a reading while accelerating?

    Thanks guys!
     
  2. mallen

    mallen Y-Block King

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    Didn't you have to change the starter on the turnip truck? What was wrong with the original starter and do you still have it. Was the solenoid ok? For that matter, even if it was not, you might have enough good parts to make one good solenoid. If not solenoids are cheap and readily available. Most older gm vehicles used that part. In fact, if you have any old gm starters laying about they might have one.
     
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  3. 72soa

    72soa High Wheeler

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    Vac. is good. A stock IH SV will pull at least 20 inches of Vac. You are a little low but there is some room with some timing and carb adjustments. What you have is good though. It idles smooth and is ready to rumble.
     
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  4. 1975IH200

    1975IH200 Y-Block King

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    The GM style solenoids used on the IH/GM style starter can be disassembled, cleaned, and the contact washer can be flipped over.
    The fresh side can then be used for the contact side.
    Also, rebuild parts are available, or used to be available, from NAPA or others.
    Also, NAPA p/n ST124 is the "heavy duty" or 'long style' of starter solenoid.
    It will reach the starter contact lug directly without the use of the spacer.
     
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  5. TheCrazyFarmer

    TheCrazyFarmer High Wheeler

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    I replaced the starter on The Turnip Truck, because it was cranking super slowly, and it wasn't the battery. After I replaced it, it cranked like it should. I don't have the old starter because, unfortunately, that was back when I didn't realize it was a good idea to hang on to old parts. When the guy at the desk told me he would take the old one for the core charge thing, I thought that's how it was done.

    If my vacuum is fine, then I need to figure out what else could be causing the backfiring. I've gone over the ignition system, there's enough fuel getting to the carb, there's not too much fuel going to the carb, so I think I'm pretty much down to the carb itself.

    I'm on a real time crunch here. We have several big projects that need to get done before the rainy season, and we need Big Onion to do them. This means, if there's a way to do something faster, for a bit more money, its worth it. Time is money right now. If it seems like there's stuff going on with the carb, and its more than can be fixed with a few adjustments, buying a new low end/refurbished carb would be a better use of my time. If anyone has any advice on fine tuning the carb, it would be most appreciated.

    I also have to deal with the water pump, dang it! How should I go about this? Where do I get a new pump, and how do I replace it? I want to start preparing for that.

    Thanks guys, You're all a big help!:cowboy::thumbs up:
     
  6. Gunfighter97

    Gunfighter97 Binder Driver

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    https://www.ihpartsamerica.com/store/IHENG-WTRPMP-N.html
    This pump should be the ticket, first step for finding a replacement carb would be the stamp on the housing near the choke flapper (inside the air filter) and find one that will perform to similar specs/or a rebuild kit. They aren't hard to rebuild, I have one that I did in two one hour long sessions with an overnight soak in fresh acetone in between. Haven't tuned it yet, its a ready replacement for when my po jb weld mess finally gives out.

    Sent from my LG-LS993 using Tapatalk
     
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  7. TheCrazyFarmer

    TheCrazyFarmer High Wheeler

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    Thanks! I better order that soon. I don't know how long it usually takes to ship.
     
  8. TheCrazyFarmer

    TheCrazyFarmer High Wheeler

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    Do you think the fact that the PO bypassed the governor could be causing issues?
     
  9. 1975IH200

    1975IH200 Y-Block King

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    Last edited: Aug 23, 2020
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  10. 72soa

    72soa High Wheeler

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    I have dealt with backfiring issues in the past. It is almost always ignition. Does this thing have a points type ignition?
     
  11. TheCrazyFarmer

    TheCrazyFarmer High Wheeler

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    Nope, it has a PerTronix ignitor.
     
  12. TheCrazyFarmer

    TheCrazyFarmer High Wheeler

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    Thanks! That's a good article!

    I'm gonna print out that sheet, and see what I get.
     
  13. TheCrazyFarmer

    TheCrazyFarmer High Wheeler

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    here are the vacuum reading while working the throttle. At the beginning of the video, I am opening the throttle fairly quick, and the needle starts out at a little under 20 at idle, then drops down close to 10, and then goes up to about 22, before settling back down to a little below 20. Towards the end of the video, I'm opening it faster, and it goes from a little under 20, goes down to about 10, and returns to the starting point quickly. I am having trouble identifying it based on the chart.

    By the way, I was not opening the the throttle all the way. I don't know if that's an issue or not. If I open it all the way quickly, it backfires. Let me know if I need to test it again opening the throttle all the way.

    Thanks guys!:cowboy::thumbs up:




    yvlyhvg;iyiug;.png
     
  14. scoutboy74

    scoutboy74 Lives in an IH Dealership

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    Seems like fairly normal vacuum behavior. Is the backfire out the tail pipe or through the carb?
     
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  15. TheCrazyFarmer

    TheCrazyFarmer High Wheeler

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    I believe its backfiring through the exhaust. I remember before I hooked up my new exhaust, I could see a blue flame coming from the exhaust manifold.
     
  16. TheCrazyFarmer

    TheCrazyFarmer High Wheeler

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    I ordered my water pump from IHPartsAmerica, and that is supposed to get here sometime soon.

    If I was to go the route of a new carb, I would be getting an el cheapo one (AKA NOT HOLLEY) off of amazon or something. The problem with that, is I don't know what models would work. What other cheap carburetors are interchangeable with a Holley 2300?

    If I go the rebuild route, what areas do I focus on in particular? What could be going on with the carburetor to cause the backfiring?

    Do you think fine tuning the carb would do any good? Or do you think there's more to it than that? I feel like it should run good enough without fine tuning, but I could be wrong.

    Thanks!
     
  17. mallen

    mallen Y-Block King

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    Check the distributor shaft for excessive run-out and make sure the vacuum advance and mechanical advance are working right and set initial timing to zero degrees if you have not already done so. The to check the shaft for run-out put a dial gauge on the shaft and pressor with your finger. It should not move more than a few thousandths. If it moves like 20 or 60 thousands or something, it's a problem. Then disconnect the vacuum advance. Run the engine at various rpm. Check the timing advance at the various numbers listed in the service manual. In other words do you see 0 at idle and the specified mechanical advance at 200 rpm or whatever rpm is listed in the manual. Then run the engine at idle and hook up a handheld vacuum pump to the advance can. Verify the vacuum advance is giving you what it lists in the manual. From there, look to your carburetor. I'd rebuild or have rebuilt the carb you have if it's the one that came on it. Verify that it is if you have not already. Then I'd hook it all back up like it was supposed to be, including the governor. (Also check that the distributor is original, or at least the right kind)
     
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  18. TheCrazyFarmer

    TheCrazyFarmer High Wheeler

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    This is really good info, but I'm afraid I don't have a dial gauge or a manual. I'm not sure how I can set the initial timing on this truck. I did it on the turnip truck, but on this truck, there is no room underneath to turn the engine manually. Any tips?

    Thanks!
     
  19. scoutboy74

    scoutboy74 Lives in an IH Dealership

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    It starts and runs so you can skip ahead to hitting it with a timing light to see where it is at hot curb idle and vac advance plugged.
     
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  20. TheCrazyFarmer

    TheCrazyFarmer High Wheeler

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    Okay good.
     

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