My 1971 521

[d.p]

It’s weird cause it just seems to be at idle.  Like before it was right around 14.x and now it’s 16-17+ at idle. If I gas it it drops but it just seems to be super lean at idle but fine while driving.  Like 11-13 putting around and a little lower at WOT.  

[mainer311]

1 hour ago, d.p said:

Ok so this is what I will need?  4 of them?

 

https://www.shop.upgrademotoring.com/Mikuni-Carburetor-Pilot-Jet-65-40-44PHH28-N101043-65-MIKN101043-65.htm?categoryId=-1

 

 

That be them.

[Crashtd420]

1 hour ago, d.p said:

It’s weird cause it just seems to be at idle.  Like before it was right around 14.x and now it’s 16-17+ at idle. If I gas it it drops but it just seems to be super lean at idle but fine while driving.  Like 11-13 putting around and a little lower at WOT.  

I have seen similar numbers in the mornings when it's really cold, but only during startup... once warm the idle numbers where fine....

From what you say a main jet change won't really help you then...

Personally idle it high till it warms up and see what the readings are....

Unless it stays at or above 16 after warm up I'd leave it alone....

[d.p]

I think I’m going to check the timing and make sure they are all in sync.  I don’t know what would cause the change ? The only things that have changed are the fuel pump and the speak plug wires.  And well the weather but other than nothing else. 
 

I mean it was right around 14 at idle, rich under load and then lean right when I came off the gas but now it’s just lean at idle while everything else remains the same. 

[mainer311]

If it’s lean at idle, and that’s it, just turn the idle mixture screws 1/4 CCW.

[d.p]

Just now, mainer311 said:

If it’s lean at idle, and that’s it, just turn the idle mixture screws 1/4 CCW.

yeah only at idle. So turn them (CCW) out to richen up the idle?  

[mainer311]

Yep

[Crashtd420]

12 hours ago, mainer311 said:

If it’s lean at idle, and that’s it, just turn the idle mixture screws 1/4 CCW.

Kind of what I was thinking too...

[d.p]

Backing out those idle mixture screws seems to have done the trick.  Guess I will just need to turn them in when the weather warms up? 

[d.p]

Anyone run 16" wheels?  I really love these but not sure 16" is going to suit my fancy...16 x 8 +0.  If they were 15" I wouldn't hesitate and the reason I ask is I have a set of Chevy rallye wheels on tires that get absolutely no use so I figured I might as well buy another set of wheels and be done with those.  

 

[mainer311]

Your current wheels are the tits. Why change to something like this?

[banzai510(hainz)]

the wheels you have right now hide your drum brakes better.

[datzenmike]

Paint then same color as the body.

[mainer311]

5 minutes ago, datzenmike said:

Paint then same color as the body.

 

That thing will look like a fuckin smurf going down the road.

[d.p]

I have a wheel fetish.  I am going to buy another set of 15s when that perfect set presents itself.  They have yet to materialize but they will eventually. 
 

Finding a nice set with the right size offsets in 6 lug could be a full time job. 

[mainer311]

Have you tried www.croooober.com? There’s an English translation button at the top. You can do a wheel search with all the settings you want and see what shows up. I bought a set of Watanabes for my roadster on there.

[d.p]

Nah is that the same as buyee.jp?  I just took a look and couldn't figure out how to search on it.  

 

For instance this is the search I use in buyee:  https://buyee.jp/item/search/query/6x139.7+15?conversionType=top_page_search&searchHis=1 

[mainer311]

It's not the same as Yahoo auction. Croooober is the online retail shop of a chain of stores in Japan called UpGarage. The wheel section is a consignment shop of people selling wheels in Japan that ships worldwide. 

 

Click the "EN" button in the upper right. After doing that, a huge "find wheels by specification" banner shows up on the homepage. 

 

It's hit or miss. There's a lot of junk on there, but sometimes there are nice sets of Work, Watanabe, Bridgestone, SSR, and Epsilon wheels on there.

[Stoffregen Motorsports]

There are two basic styles in the vintage mini truck world - USA and JDM. The look of your truck right now is definitely American, and I like it. JDM has a very different look, and I like that too. Swapping to a more JDM wheel will change the entire look of the truck.

 

Also, remember that wheels are jewelry and should be changed often.

[mainer311]

1 hour ago, Stoffregen Motorsports said:

There are two basic styles in the vintage mini truck world - USA and JDM. The look of your truck right now is definitely American, and I like it. JDM has a very different look, and I like that too. Swapping to a more JDM wheel will change the entire look of the truck.

 

Also, remember that wheels are jewelry and should be changed often.

 

Huh? He has the most JDM wheels you can get on his truck right now. 3-piece Deerfields.

Edited January 14, 2022 by mainer311

[d.p]

These bad mamma jammas.

 

[wayno]

OK, let's talk about gearing for YOUR truck, I am not good with tire sizes and gearing like Mike is, so maybe Mike will answer what the gearing will be with your tires and specific gears.

 

I have already mentioned in Oilspot's thread that the set of 3.89 gears I have are rusty in areas of the ring gear and I would not be comfortable on selling them, I also have mentioned that you need to try and start your truck in 3rd gear and see how easy it is to do that, you have to be honest with yourself about that, is it really easy to get moving in 3rd gear, the reason I ask you to do that is because I do have a set of 3.7 gears that I would sell you, but I have no idea what it will be like for you to get the truck moving.

 

That said I had these gears in my 720 diesel with an SD22 engine(61hp), them engines do not have a lot of HP, but they have torque, so I could get it moving with them gears but it had a hard time keeping it moving at freeway speeds, I think I was in 3rd or 2nd gear going up a hill on hiway 101 in north CA one time in my silver 720 diesel with 3.89 gears, and decided something had to change and that was when I bought that first turbocharger but it sat on the shelf for years as I sold that 720 diesel truck soon after that trip and I started my 521 kingcab SD25 diesel build.

 

So you need to see if you can get your truck moving in 3rd gear or wait till Mike reads this and tells you/us what the gearing would be with your tires and 3.7 gears, here are two photos of the 3.7, as I said it is very dusty and needs to be cleaned but they are not rusty.

 

 

Edited February 5, 2022 by wayno

[datzenmike]

Need this info fresh and on this page so I can refer to it easily and not keep forgetting and having to ask or hunt 4 or 5 pages on different posts.

 

1/ Start with what engine you have? Larger L20B will out pull an L16 and can go lower number ratio differential.

 

2/ The 521 has a 4.375 differential with 6:00 X 14 tires. I think they are around 26" diameter but I'm very confused on this. Didn't Cardinal Grammiter have a post on truck tires??? Tires are much different today. Need to be sure of the stock diameter before comparing it to the tires available today.

 

 3/ Tire size you plan to run. If smaller diameter than stock, this will make the differential ratio even higher than 4.375

 

[wayno]

37 minutes ago, datzenmike said:

Need this info fresh and on this page so I can refer to it easily and not keep forgetting and having to ask or hunt 4 or 5 pages on different posts.

 

1/ Start with what engine you have? Larger L20B will out pull an L16 and can go lower number ratio differential.

 

2/ The 521 has a 4.375 differential with 6:00 X 14 tires. I think they are around 26" diameter but I'm very confused on this. Didn't Cardinal Grammiter have a post on truck tires??? Tires are much different today. Need to be sure of the stock diameter before comparing it to the tires available today.

 

 3/ Tire size you plan to run. If smaller diameter than stock, this will make the differential ratio even higher than 4.375

 

 

OK Mike, this is what was said in Oilspot's thread about D.P's tire size.

 

From what I understand a 195/70r14 is pretty close to stock tire circumference at 77.7". 

A 195/50r15 rolls out at 71.2".

 

You re-geared your truck at the tire!

 

So Mike, with 195/50r15 tires what gear ratio would a 3.7 gearset be with a 71.2 round tire be compared to a stock size tire?

Would it be close to a 3.89 ratio?

Edited February 5, 2022 by wayno

[mainer311]

6 hours ago, wayno said:

 

OK Mike, this is what was said in Oilspot's thread about D.P's tire size.

 

From what I understand a 195/70r14 is pretty close to stock tire circumference at 77.7". 

A 195/50r15 rolls out at 71.2".

 

You re-geared your truck at the tire!

 

So Mike, with 195/50r15 tires what gear ratio would a 3.7 gearset be with a 71.2 round tire be compared to a stock size tire?

Would it be close to a 3.89 ratio?

I think it’s close. You can use the percentage from the circumference differences and multiple it by 3.7. 
 

So: (77.7/71.2) x3.70. It gets you right around 4, so very close to a 3.90.