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mlracing.co.nz

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Posts posted by mlracing.co.nz

  1. 2 hours ago, shrike said:

    @mlracing.co.nz

    If you had no coolant in the engine your temp sensor wouldn't have read it was overheating as they need fluid to read correctly. 

    In regards to the carbs, personally id be looking at efi options but thats just me 😛 

    Have you done a comp test on this motor? 

    If you have issues from overheating (ie headgasket) is it possible the 2nd carb isn't drawing as much because the cylinders that are closest too it aren't pulling as much vac? 

    Note im useless with carbs but just a thought 

    lol true, the sensor is after the thermostat so would have read nothing haha didn't think about that. Maybe I should run without thermostat and see what happens. 

    I did look into EFI stuff.. probably need about 5-7k to get it going. I'm willing to struggle more before that. The car isn't overheating.. that I know of. No steam coming out of the exhaust which might indicate head gasket, I haven't checked the oil so don't know if it's mush but also there wouldn't be water in there if there's no water in the engine so probably doesn't help. Haven't done compression test. 

    True I think it's not pulling as much vac, I need to order a proper vac tester and try get idle working so I can confirm it

  2. 1209fa4b-5385-4e84-a5af-3672ad64039c.thumb.jpg.a522b24d43c39e8e08bb834d598d9449.jpg
    To distance my brain from carb life for a while I decided to look into another thing that's been bugging me. The weird thing about this car is it's never got up to temperature, well at least it never seemed to get past the first little line on the gauge. Because of this I've always wondered if the thermostat was working properly and today I took apart some of the system to check it all.

    1ec45a5f-0ff8-4939-95d7-38b12a16e4f2.thumb.jpg.2ae059c24373d2b0ec37d4c739f22fc3.jpg
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    Once I took the hoses off it became clear that there was a thermostat problem, however it was the opposite to what I was expecting. This thing is jammed shut. I was expecting one to either be jammed open or not there at all. This might be the original (or very old at any case) thermostat, so definitely due for replacement.

    45168ab5-d195-4563-b56c-c1e7e14074f4.thumb.jpg.ab3d61b24843cbef849d035c1c4665eb.jpg
    Also abundantly clear that there's been no water circulating in the engine for some time as the coolant that came out of the radiator was green, not mud. This got me wondering.. has there ever been any in there since I've owned it? How long has there not been water circulating ? I have actually taken this car to some events in the not so distance past and the temperature never moved then either. Does this engine somehow have the power to never overheat?

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    This radiator has seen better days but it never leaked from memory so I don't think it was blocked and stopping flow. That said I might get it reconditioned or replace it anyway for peace of mind. As well as replace the radiator hoses as they looked pretty second hand.

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    I'll also be bypassing the heater core so the hoses along the top here are being removed.

    So now I'm thinking I need to get new thermostat, pipes, some block off caps, a few gaskets and perhaps I should check the water pump as well.. it's probably not been doing a whole lot.

    • Like 4
  3. Rant update I'm afraid. 

    Accelerator pumps still not working on either carb which means idle doesn't work properly and any throttle coming off idle at all just stalls the car. Additionally the balance of the carbs is now way off and the ignition timing has gone super weird. At one point the car wouldn't even crank over at all which made me think did I somehow cause some catastrophic damage while messing around with the disitributor but that doesn't make sense as it was just changing ignition timing. 

    So basically I was just getting frustrated and turning screws and fucking about without a proper plan which is not good and not helping. Taking a step back I really can't proceed without working accelerator pumps so this needs to be resolved first. If the car cannot even idle then I can't do anything else. I'm tossing up getting the next size up idle jets too, 50/50 on it. 

    If I can't fix them somehow then perhaps I will need to send them out to get checked over by someone who knows a thing or two about a thing or two. Another option is to get some other carbs like webers or something but we'll see, not at that point yet. 

    • Sad 2
  4. 20250618_120417small.jpg.4fad777ececfa088330d77124d97fee5.jpg
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    So this is the diaphragm situation. As you can see the new ones (red) are a bit different to the old ones. The height is a little different, the diameter of the metal bit is a few mm different and the spring that goes with it was different. I presume all of these things together mean no bueno. Reluctantly I have reinstalled the old ones as they didn't seem damaged, just crusty. No tears or anything. 

    Yet to test, too many sook businesses around during the week so I'll have a go on the weekend and see if it made any difference.

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    One thing I did notice is there is a little bit of moisture that appears after running the cold start circuit for a little bit, not entirely sure what that is and it goes away but there's no gasket or anything there so I guess that's just how it is. 

    Also something I learnt is there is different timing between the "early" 2T-G and "late". Mine is an early build (remember the engine is not from this car so it's been a bit of a puzzle to put together what came from where) so I have to get that back in spec again too. 

    • Like 8
  5. 20250613_114118small.jpg.59ae7e53a2a7622ebc987135e94ab3bc.jpg
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    First time I've taken apart carbs before and given them a proper clean with new gaskets and inspection. Actually they don't seem too difficult but there are a large number of tiny little parts that easily go missing. This is the actual reason I purchased an ultrasonic cleaner about 2 years ago and it does an awesome job. I was just using a splash of dishwashing liquid in there, nothing fancy. 

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    I only worked on one at a time which was good because I found a few errors along the way on the first one after dismantling the second one and ended up losing one of the tiniest washers I've ever seen. Thankfully my hoard delivered and I had a rebuild kit for a slightly different Mikuni which also used the same washer so was able to salvage a replacement from there. Once reinstalled they look great but I had to do some re-setup as I'd fiddled around with the screws and what not. 

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    After some time it seems like maybe the rear carb is not pumping enough fuel compared to the front carb, and the car may be running basically on one carb at idle. Rear plugs looked like this.. seems lean. Front actually didn't look too bad. 

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    Also there's a hesitation problem coming off idle when there's a bit of throttle applied. This is annoying and causes stalling sometimes. It seems to be a new issue and the only thing I can think of that has been changed during the rebuild that might do something is the spring for accelerator pump diaphragm under this cover. In the rebuild kit I was using there was a spring included which was a different height to the one that came out. I didn't really think anything of it, just figured a new one would be better but perhaps that's the issue. Once it gets past that little bump she revs no problem. 

    I'll get the spring changed out next week and see if that makes any difference. Also may look into getting a proper vacuum tester as the unisync doesn't really seem to tell me much aside from front carb is pulling vacuum, rear carb isn't nearly as much. Aand despite gooping the exhaust up, there are still some leaks so suppose I'll have to break out the welder again and try fix it properly. 

    If anyone has additional ideas feel free to post them in yarns thread.

    • Like 8
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