2.4L Chrome Bore 175 Running Issues

**Baker343** · 07-29-2022, 10:45 AM

Try your xr2 carbs on your 2.4

**pcrussell50** · 07-29-2022, 12:20 PM

Subscribed.

I hate tough mysteries when it comes to motors that I have myself, and am always hoping it gets fixed so I can learn from it.

-Peter

**TEXAS20225** · 07-29-2022, 08:24 PM

i had a 88 xr2 i took in trade on a 200 efi for a guy who had way too much boat for a 150 it was a23 ft center consol from the coast they had wh40 on them i still have them thy had 80 mains in all of the carbs

**croSSed** · 07-29-2022, 08:30 PM

Originally Posted by Baker343

Try your xr2 carbs on your 2.4

Are the carbs the same, except the jets?

**Baker343** · 07-29-2022, 11:00 PM

Originally Posted by croSSed

Are the carbs the same, except the jets?

Most WH carbs that came off 80's fishing motors had the same venturi size. Early 80's 225's had bigger. I have a set of 31's that I've used to identify carb issues. Some carbs just can't be fixed

**Baker343** · 07-30-2022, 12:40 AM

Yes the carbs are the same. Your mains on your xr2 carbs are probably 64's if stockish. They will work on your 175 for a quick pull. Bottom to mid is what your looking to correct, you can add main jets sizes for the big end if these carbs correct your issues

**rckid74** · 08-02-2022, 02:11 PM

Originally Posted by croSSed

All the pistons are on the correct sides, and not upside down. I ran it w/o cowling and air box cover to really hear it run. It runs - as I would say - ratty. Rattles, vibrates, doesn't seem like it's firing on all 6 all the time. Switchbox swap didn't change a thing. Seems to run fine above 4000 rpm. I dropped my XR2 back on and I'm running. Just not as much power.
Attachment 508125

Make sure you don't have two of the coil leads from the switchboxs interchanged.

**Dave S** · 08-03-2022, 06:07 AM

Yellow Melllow.......

Goood to see ya still ckin' around here....rcKid

**croSSed** · 01-23-2023, 09:49 PM

UPDATE: I know this is an old thread but I thought I'd let you know what was found. It looks like the starboard side head up by #1 is warped enough to let exhaust leak into the water jacket. Would this cause it to run like described above? Now I'm looking for someone to machine the mating surface flat or find good used UNWARPED heads. Thanks for posting any further thoughts on this. Peace.

**rgsauger** · 01-24-2023, 01:31 AM

Bunches of folks can cut your heads. JSRE Jay Smith Racing does a lot down here in TX

**OnPad** · 01-24-2023, 02:33 AM

I doubt it would cause the rattle, unless it was sucking water, and killing the spark. Or had done some damage to rings, rods, or bearings?

It usually takes alot of heat to warp a head.
Possibly enough to melt glue or demagnatize flywheel magnets, or make cylinders out of round?

I would still recommend running a timing light on all cylinders. Make marks on flywheel with white paint and label 2-6.

Compression test isn't going to tell you if you have a broken reed, unless it did damage.

**Baker343** · 01-25-2023, 02:16 AM

Originally Posted by croSSed

UPDATE: I know this is an old thread but I thought I'd let you know what was found. It looks like the starboard side head up by #1 is warped enough to let exhaust leak into the water jacket. Would this cause it to run like described above? Now I'm looking for someone to machine the mating surface flat or find good used UNWARPED heads. Thanks for posting any further thoughts on this. Peace.

Does the top of the #1 piston looked to be washed out by water. Have both heads cut a little and throw some new head gaskets on and retry.

**Dave S** · 01-25-2023, 02:58 AM

Make sure ya not using 2.0 head gaskets on a 2.4.....

.....Also on early 2.0/// or any merc.... make sure the choke enricher bolt is not tooo long.... will give a vacume leek.....

...

**croSSed** · 01-25-2023, 10:30 PM

Originally Posted by OnPad

I doubt it would cause the rattle, unless it was sucking water, and killing the spark. Or had done some damage to rings, rods, or bearings?

It usually takes alot of heat to warp a head.
Possibly enough to melt glue or demagnatize flywheel magnets, or make cylinders out of round?

I would still recommend running a timing light on all cylinders. Make marks on flywheel with white paint and label 2-6.

Compression test isn't going to tell you if you have a broken reed, unless it did damage.

Some clarification: The warpage had to have been caused before I got the motor. My engine builder did not notice any warpage, but... He said there was no indication of water intrusion into the comb chamber, BUT some of the plugs when I pulled them looked really clean. If any amount of water was getting into a comb chamber it would clean the plug, and make it run like s--- at low rpm, and even make it die at idle. If the leak were not really bad it would still run at high throttle positions. Me just speculating...

**OnPad** · 01-26-2023, 10:06 AM

Originally Posted by croSSed

Some clarification: The warpage had to have been caused before I got the motor. My engine builder did not notice any warpage, but... He said there was no indication of water intrusion into the comb chamber, BUT some of the plugs when I pulled them looked really clean. If any amount of water was getting into a comb chamber it would clean the plug, and make it run like s--- at low rpm, and even make it die at idle. If the leak were not really bad it would still run at high throttle positions. Me just speculating...

Sounds like a possibility.