Afterfire pop?

[Husker]

Spent the last 3 days driving my Jeep day and night out at an event in West Virginia. Most I have used it ever preformed great towed the loaded 416 and pax up steep off-road trails. Found out my VRC46 radio didn’t work so well and I noticed a few things about the Jeep

Every once and a while it would let out an after fire pop a couple seconds after engine shutdown. Is this cause of to rich a mixture? Elevation was about 2000 feet or so and I only ever drove it at sea level before.

My speedometer seems loud does it accept any form of lubrication?

Finally I think my rear diff yokes are going out I don’t recall the order of symptoms if bad ujoints mess the yokes up or other way around
Front has new joints no sounds. Rear makes clunking noises at any speeds intermittently. New rear joints are on the menu in the coming weeks and I’ll see if the noise goes away but there is already a little up
And down play in the yokes.

[rickf]

The pop is usually caused by idling fast and shutting it off combined with am exhaust leak somewhere up close to the engine. The rich mixture gets trapped in the exhaust pipe when the engine is shut off and it is plenty hot enough to explode, all it needs is oxygen, if you have a leak there is the oxygen. Bang.
Speedometer cable may need lube, you can pull out the cable from the sheath and lube it and put it back in.

On the axles are the slip yokes free and moving in and out?

[Husker]

The Axles will slide in and out but with a little force

I have a noise that sounds like it’s coming from the speedo or maybe the cable but the cable was brand new kinda like a whipping rollery noise

I’ll look for an exhaust leak up at the head I tried spraying some starting fluid but that probably only works on the intake!

[rickf]

The speedo cable was brand new................ But how many years ago? The grease could have dried out. How high is your idle? It should be fairly low. Even with a rich idle and exhaust leaks they don't usually backfire unless they are running fast enough to dump a lot of raw gas at shut down.

[mutt and jeff]

And don't use starting fluid looking for an intake leak, use carb cleaner. It will slow down or kill the engine. Starting fluid will just burn off, or explode.

[1SGCAV77]

As for the noise at rear differential. I had same noise when I first purchased my M151A1. I did exactly what Rickf said about the slip joints. I removed, took apart, cleaned, lubed, checked u-joints, and installed new mounting bolts for differential. Noise was gone. One thing about the M151series....grease zerts are there for a reason. My 14yr old grandson said, “ dad doesn’t have to grease his Jeep, Paw”. Different jeeps Buddy. The 151 just isn’t a throw away like your dad’s Jeep. 151 doesn’t have all those plastic components like your dad’s either.

[Husker]

Thanks guys I’ll give it a look
Getting the Jeep off my deuce in a few minutes

[lpcoating]

What was the event in WV? Are you going to Graves Mountain MV trail ride?

Guy

[Husker]

It was a big airsoft game I’ll post some photos today in the other section

When is the graves event

[lpcoating]

Sept 3-7th.

Guy

[Husker]

Is it just a show up and pay event or do you need to pre register? It’s only an hour and half away from me!
But I would need to figure out leave etc most likely I couldn’t do it cause of covid maybe a day trip would be doable

[lpcoating]

http://g838.org/viewtopic.php?f=15&t=12683

[TFischer]

Spent the last 3 days driving my Jeep day and night out at an event in West Virginia. Most I have used it ever preformed great towed the loaded 416 and pax up steep off-road trails. Found out my VRC46 radio didn’t work so well and I noticed a few things about the Jeep

Every once and a while it would let out an after fire pop a couple seconds after engine shutdown. Is this cause of to rich a mixture? Elevation was about 2000 feet or so and I only ever drove it at sea level before.

My speedometer seems loud does it accept any form of lubrication?

Finally I think my rear diff yokes are going out I don’t recall the order of symptoms if bad ujoints mess the yokes up or other way around
Front has new joints no sounds. Rear makes clunking noises at any speeds intermittently. New rear joints are on the menu in the coming weeks and I’ll see if the noise goes away but there is already a little up
And down play in the yokes.

Did you figure out the after pop cause? I have this same issue

[Mark]

I had same problem, I leaned the carb's fuel mixture maybe something else with the carb?

[TFischer]

Mark,

That as a good idea to lean out the mix. I’ll post my results in the next few days.