2.4 Cold seize cause this?

**coffeeguy** · 10-20-2020, 03:45 PM

200 Carb ,weisco piston, has steel liner,happened around 5000rpm well warmed up. Could it be started by a cold seize or lean condition. Carb was clean inside and main jet clean also(wh-15 72 jet). All other plugs where a dark tan and piston tops good

**Merc 2.5** · 10-20-2020, 04:53 PM

Thats just lean. If it burns piston at exhaust port its lean , hole in top detonation, cold sieze would stick all way up and down cyl. Maybe I stepped off a limb sayin this but ill b corrected if I'm wrong. Cyl 2 and 5 should always b jetted up least 1 size on a 2.4.
Also looks like intake side pretty dry

Guys help me out if I'm wrong here , everyday I learn sumthin new is good day

**FMP** · 10-20-2020, 05:32 PM

Took some local heat , how'd the ring to roof look?

**rgsauger** · 10-20-2020, 09:47 PM

My #6 just did that in my 2.4, too. It's trash in carb/jet or switchbox breaking down and double firing. Mine wiped out the chrome bore so I'm getting a sleeve. I have wiseco too. Happened around 5k too
Sucks

**coffeeguy** · 10-21-2020, 04:35 AM

Third pic shows abit of aluminum transfer.(like a thin solder splat when doing plumbing)

**Dave Strong** · 10-21-2020, 10:28 AM

Lean

Dave

**rjdubiel** · 10-21-2020, 10:46 AM

72 main is lean for a 2.4 usually.

**coffeeguy** · 10-21-2020, 04:23 PM

It was an 80 225 frount and wh15s(72s in all 6) ,34cc heads, on a newer late 80s block,over the years it has suffered a wiesco locator pin failure (same cylinder). It was always abit rich. What would be a better starting point for jetting?
I am thinking 78s on 2 &5 and 76s on the others, or would even bigger jets be better. I find it confusing how some of the newer carbs have much larger jets then the old whs.

**rgsauger** · 10-21-2020, 05:16 PM

mine...Attachment 475575

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**rgsauger** · 10-21-2020, 05:18 PM

James Perry is sleeving my 2.4 block. He said if a switchbox is acting up and double firing, then it can do that too because it causes things to go lean. Said MUST test/check the switchbox before putting motor back together. If he was doing it, he would insist on using new switchboxes. Interesting.

**Merc 2.5** · 10-21-2020, 05:21 PM

Originally Posted by rgsauger

James Perry is sleeving my 2.4 block. He said if a switchbox is acting up and double firing, then it can do that too because it causes things to go lean. Said MUST test/check the switchbox before putting motor back together. If he was doing it, he would insist on using new switchboxes. Interesting.

Yes but he's just lean , wrong jetting all together. 1 pic shows little bit of #4 and it was looks little dry to

Most stock 2.4 200s with no mods and wh carbs came with 76s-80s. Hes runnin 72s in all and modified heads

**coffeeguy** · 10-21-2020, 07:17 PM

The 80 2.4 225 came with 72s

**Merc 2.5** · 10-21-2020, 07:21 PM

Originally Posted by coffeeguy

The 80 2.4 225 came with 72s

Wow. I know on the wh46s was 78 and 80ish that was for 200
72s isn't enuff imo. Take pick rest of pistons for us

If motor pretty much died round 5k rpm u should still b able tell if lean or rich

**Capt.Insane-o** · 10-22-2020, 02:30 PM

lowest i ever went in a 2.4 200 was 82...usually 84s and in the fall or spring 88's

**rjdubiel** · 10-22-2020, 03:17 PM

Lots of info needed that is not supplied. I would say you were lean. But lots of questions could be asked and all sorts of discussions could take place here! Looks like your already set up for a oversized piston and I would go with bigger mains. But again, airbox or open carbs, what adapter plate, what water pressure did you have, water pump good? and lots more questions! i am guessing could be asked.