YD100 anybody got one?

Like I said it's in the clutch, springs too strong or oily pads. There are too many model names/numbers to keep up with, you're probably on the right track.
 
Greg58 said:
Like I said it's in the clutch, springs too strong or oily pads. There are too many model names/numbers to keep up with, you're probably on the right track.
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I think its oily pads do i have to disassemble the clutch to deal with that problem and is it a tool i should use?
 
oddengines said:
How far off was the stihl jug? Was it close enough that the jug could be modified instead of the case to mount it?
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Yeah looks like the holes in the jug could be slotted to fit the stud spacing. Didn't have a base gasket for the Stihl jug to try on the studs and the YDs gasket was stuck well to the block so I couldn't try it on the Stihl jug either.
 
Bigwheelz said:
Its an automatic clutch bt 80 electric start no handle to release. And thank you !
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Yes, it has no handle. Start it with the starter, recoil or electric(recoil is junk) and twist and go. Has a large wet clutch that is very smoth and should last about forever.
 
I was trying to help him but know very little about that engine, somewhere I saw a manual on it a couple of months ago
 
Greg58 said:
I was trying to help him but know very little about that engine, somewhere I saw a manual on it a couple of months ago
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Yea there is a manual but its mostly just how to put it together and minimal maintenance, might be oil seal gaskets....a guy i ride with in this club hooked me up with a spare china girl.

So im re-taping the stud mount holes and gonna use that until i get the bt80 squared up....

But still all info on the BT IS MUCH APPRECIATED!!! Happy riding!
 
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I’m new to this just built my first bike and it was so much fun building it I want to do another. I’m 45 (old guy) 6’4” and almost 300 pounds (big fat old guy) but a kid at heart like most of you. My question is can you port out the yd100. I hear the motor has good torque And me being a big big guy it might be the one for me. O ya my first build pic everybody likes pics.
 
Well after 450mi with this engine on a 10mi daily commute I surmised the initial timing is too advanced. Engine ran ok but was jerky or bucked a bit in the low to mid range at cruise. Kinda irritating. So I retarded the timing half a key width and what a different engine it is now! Really much smoother from idle to top. The low end increased, and got a bit more top end too.

A member of another forum had figured out several years ago that the CG cdi had too much advance and built a unit with a lower value that gave excellent power. The cdi advanced too much for the stock initial setting. I’m believer now in his research as retarding turned this engine in to a much smoother tractable runner all thru the band.
 
I will be looking at this engine. To see how well it works over time. Some of the newer 69cc two stroke engines are getting cylinder with cast iron sleeve. Would like to see that in 100cc engine.
 
Yep cast liners are a great thing. This of course is a 79cc. I suspect the cast liner jugs will become more common as the next great thing for the CG engines. Once one manufacturer goes that way the others have to follow suit to stay in the game.
 
Well I’m about 150mi into the timing retard. The advantages are well worth it. Super smooth idle, fat bottom end and believe it or not 4mph top end increase. This follows much that has been written about overly advanced timing on two strokes. It seams half a key width is 4-5degrees which is about right for these engines from what I have read. This mod certainly improved the YD and probably any CG running the stock CDI.

My final thoughts on the YD is its a very fine engine. It has required very little tweaking compared to the usual CG. The NT carb it came with must have been tweaked by the manufacturer for the engine jet and needle wise. Only requirement to tune it was to drop the needle one notch. Has never 4stroked and is very responsive. This engine is very smooth. It’s the most pleasant to ride of any 2stroke I have had from China including my next favorite BT80. Don’t know and don’t care how it may or may not tune for max power, I leave that for others to figure. In my opinion/experience this is the best out there at the moment for a great daily rider. It just plain runs great!
 
Widening the key way I find it easier. Got a bunch of rotors on experiment with. I scored the rotor at half a key width and filed to that point. May take a bit more off just to see where the point of too much is. If you have ever set up an older outboard the timing does much of the low speed “throttling” before the carb even begins to open. Seems like a bit more might be good. Just a gut feeling.
 
Might not have made it clear, I’m filing the key way in the rotor. When you do that and hold the rotor against the mags laminations and tighten the rotor nut it rotates the crank clockwise while tightening retarding the timing. tightening the nut is more than sufficient to lock the rotor in place.
All that saidI filed the rotor to 3/4 the keys width and it’s even running better. It will idle so low and smooth it’s crazy 1450rpms! It’s even a bit smoother and snappier over the whole band. I’m satisfied where it is now. Somebody try this on a CG.
Realize this will not fix other poor running problems. If you have a sorted out decent running engine, it should improve it noticeably.
 
I feel that timing is a big difference in some engines, looking at the key way cut. I bet if you mic 10 you may find two the same.
 
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