FYI for people wanting to do the ld100 conversion for yd100

Sloppyslopster

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Hey everyone, more importantly, yd100 users.

I made a discovery tonight that apparently not all yd100s are compatible with the ld100 jug conversion! Now you're probably wondering why that is, right? Well apparently the ld100 jug doesn't like 40mm cranks! Resulting in the piston going too far up the bore and hitting the head and the biggest tell of all is that piston skirt exceeds the allowable length for the exhaust port (Picture down below). Not sure if anyone has made something about this before but I just wanted to share my findings so people can not waste their and money like I did. If you're yd has 38mm crank, you're good. 40mm is a no go unfortunately.
IMG_5164.jpg
 
Could you make a 2mm spacer for the jug?
I don't have access to a cnc of any sorts right now. Saw a video of a guy taking a hacksaw to an old yd100 jug and using that as a spacer, but I feel like that's just asking for air leaks and scaring. Unless someone on here sells stuff like that or there's a dedicated shop for stuff like this I just can't really do much. If I can't find something like that I might just shelf the engine for a later date, funny enough it's a perfect match for a ms660 conversion lol. Might actually buy a quality engine this time and just move my expansion chamber, carb setup, and head over to the new one.
 
I don't have access to a cnc of any sorts right now. Saw a video of a guy taking a hacksaw to an old yd100 jug and using that as a spacer, but I feel like that's just asking for air leaks and scaring. Unless someone on here sells stuff like that or there's a dedicated shop for stuff like this I just can't really do much. If I can't find something like that I might just shelf the engine for a later date, funny enough it's a perfect match for a ms660 conversion lol. Might actually buy a quality engine this time and just move my expansion chamber, carb setup, and head over to the new one.
Did you try a couple of base gaskets?

The floor of the exhaust port should be flat.
 
Did you try a couple of base gaskets?

The floor of the exhaust port should be flat.
Already had two or three on there couldn't remember honestly and 2 head gaskets. I think I might just go through with the phantom conversion, seems easy enough. Only downside is that I can't just buy the cylinder, I have to buy them both as a combo. I would like to just buy the cylinder and buy a hyway piston.
 
I don't have access to a cnc of any sorts right now. Saw a video of a guy taking a hacksaw to an old yd100 jug and using that as a spacer, but I feel like that's just asking for air leaks and scaring. Unless someone on here sells stuff like that or there's a dedicated shop for stuff like this I just can't really do much. If I can't find something like that I might just shelf the engine for a later date, funny enough it's a perfect match for a ms660 conversion lol. Might actually buy a quality engine this time and just move my expansion chamber, carb setup, and head over to the new one.
Makes me wonder if a 3d printed spacer would work.

Given you'd need a file, It'd be a little tricky to draw.
 
Feel like the heat from the engine would melt it over time no?
Depends on the filament material. They make higher temp filaments. Anything that can survive up to 400F would work just fine. The gas and oil exposure and heat would eventually cause it to get brittle, but you can always print more. I would definitely do a 100% in-fill for durability.
 
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