r/hondagrom • u/PropertyDue739 • 1d ago

Help! Engine Seized

SF engine suffered sudden catastrophic total loss of oil while going highway speed. Seized up. Is there a direct bolt for bolt Chinese copy of the engine that requires no modification whatsoever?

Would it be more sensible to rebuild my current engine? I believe both the crankshaft and top end need repair.

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3

u/DawgOnaBone 23h ago

Check your marketplace… where I am there’s usually one or two stock Grom motors for sale for a $300-ish at any given time. But there’s a bunch of motors that will fit, I’m pretty sure a Boom Vader is a direct replacement (it’s made entirely of Honda replacement parts, when they say it’s a “clone” it’s not a euphemism.)

You can buy a stock size OEM or aftermarket crank/rod/piston/cylinder and replace any head and rebuild yours cheap enough too.

If you want to use this as an opportunity to hot rod it with a bigger motor.
Piranha, Dayton make a motor that will drop in, but you’ll need to adapt the throttle body and run an aRacer ECU as they are all bigger CC than the Grom. Same with a cbr250/300 engine swap.

It all depends on budget and time you want to spend.

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u/PropertyDue739 20h ago

Thanks. Open to experimentation. Trying to get it road worthy and reliable as cheaply as possible as it's my only vehicle.

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u/Defiant_Parsley_3898 5h ago

Honestly if I was you, I’d be getting a cheap engine from fb marketplace or something similar, then if you want to educate yourself a little then use the old engine to strip down, maybe fit some upgrades and when you are confident or ready to swap you have a spare engine for parts

1

u/Peterdestroysall 23h ago

So you want a new Chinese top end? Or you have a Chinese engine?

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u/PropertyDue739 20h ago

It was the stock 2019 MSX125 engine. This is (was) my daily rider right now though and I need to get it back running quickly and with the best bang for the buck.

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u/Peterdestroysall 20h ago

Yeah I've swaped cheap ebay pistion/ring sets onto my 2019... for them to last less than 50 miles. I would stick to honda parts, unless you wanna swap the whole engine, and even then I don't know how much you would be saving

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u/PropertyDue739 20h ago

I'm curious about using Chinese clone parts to repair the genuine engine. Not sure if the engines are truly identical or not though.

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u/savethechows 19h ago

No they are different, a Chinese engine won’t even bolt in.

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u/ricksure76 12h ago

Just pull it down and see what's failed, but there's plenty of cheap big bore and stroke kits for these ay

Also plenty of cheap wrecked bikes on marketplace..

I'm more curious how you managed to even blow up a Grom as I highway bash mine all the time and it refuses to die after years of abuse

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u/PropertyDue739 6h ago edited 5h ago

I feel so stupid because it's my own fault. I changed the oil, and even though I checked it before I rode, I guess I didn't torque down the drain bolt enough. It seems to have fallen out mid ride and crankcase dumped all it's oil. It was instant. No oil trail anywhere. Just one puddle.

I've always changed my own oil in all my vehicles, but today wasn't my day...