motoforce crankshaft ?

[br4inl3ss]

hello.
once again talking about crankshaft.
this one is for my new 2020 Scooterre Bistro. not for the previous horror you know.

im having a hard time getting DECENT 72cc bbk right now so ill have to go for a 81 at least.
according to people 81cc is too much for stock crank. but who know... they all said to not boost a 1.5l hyundai accent they cant handle 2 psi of boost. well, they're kill themself if they knew i ran it at 15 psi dauly beaten for 3.5 years with 320 000km bone stock internals.

but as you know, with my previous "build" ( we can say re-re-re-re-re-re-rebuild ), already 3 cheap crank ( stock unknown state, no brand, and glixal ) and like 3 different bbk. so yeah i cannot afford the awesome naraku crank.

i have 2 option.... the motoforce MF30.13901 or the 101 octane BT7001-16. any experience with them ?
any better than oem and cheapo disgusting paper-made crank on aliexpress ?
honnestly  ive ran the glixal crank on my 81cc NCY bbk at 8200 rpm for a long time and the crank handled it fine. still nothing loose. but they scratch the shaft on thier own they're so damn soft WTF.
the last one i dropped a paperclip over it from about 3 foot, and it was done. scratch so deep the seal is useless when its rotating.
literally made of paper. ahd over 200 crankshaft in my hands in my life, NEVER seen such soft crank. NEVER. not even ford PoS. even lifan crank are way harder.....

i have experience with Motoforce. very good brand for its price. but what about the crank ?

or you tell me the 4000km stock crank can handle 81cc fine for some time ? like 5k km ?
need real answer. not " had one lasted 5 miles but didnt work properly so maybe bla bla bla" like we can find on the poll.

thanks.

[GrumpyUnk]

Can you polish the seal surface? When I have had grooved seal surfaces, I have used dark colored fine grit sandpaper(wet/dry) to clean up the surface. I have used emery cloth(I think, it WAS cloth) cut to width, a longish piece wrapped and moved to bear evenly. I also have set seals 'off' from fully seated or left a little higher than fully driven in to move the lip to a different spot on the shaft to avoid the damaged spot.
I know nothing about crank quality or durability.
If the glixal damaged so easily, I would be on contact with the vendor, and be demanding a replacement. A paperclip should not damage anything that is subject to the forces a crankshaft will encounter. You may have gotten a casting that was 'repaired' with the hope no one would find out until later how bad the sealing surface was from the factory. I think the site host had terrible sealing experiences on his Taotao and posted a few videos explaining his misery. I do not know if he ever got is fixed.
Send the junk back and demand a replacement.
Lifan has a good rep in my mind. I do not know if their parts will swap into a generic 139QMB or if they differentiate.
If you have access to a lathe, you could turn down the seal surface to a smaller diameter and use a seal of appropriate size. On vehicle engines, some sell thin rings that are placed over sealing surfaces to 'rescue' a crankshaft that has worn or damaged surfaces. The name escapes me...
Find a friend that can turn a brass ring that fits over the damage, and press it on... Machine shop fixes that likely don't apply to such low budget items, labor being more than the value.
tom