Dax 70 cc motor diagram?

[thatsdax]

Looks to me like ...

Looks to me like a lean condition. Either an air leak or not enough oil mixed with your gas. Looking at the pictures you have, the top of the piston looks too clean . Very clean for sure. The side of the piston looks cooked as well. How many ounces of oil per gallon of gas have you been mixing? Let us know. Thanks...

 

[thatsdax]

Looking at your pics again..

Looking at your pics again.. I must say, the top and cylinder looks clean.. Too clean.. did you do any cleaning before taking the pics? any de carbon work or anything? If not. Then.. You have a severe lack of oil with your burn. Let us know the ounces of oil per gallon of gas you were mixing. Thanks..

 

[Keepthedrivetommy]

this is probably going to make me feel like an idiot, but I am running, or was running back when the bike ran, a 40:1. I didnt do any cleaning, thats just the way that it was when I took it off. I cant exactly remember where I saw 40:1, but I know that someone else in this forum was running that after break in, so I did it also, and it seemed to be running fine.

So, does this mean that I have to order a new piston?

 

[thatsdax]

That is too ...

that is way too lean. Good for racing 2 stokes, but not yours. Even the new Yamaha's and Kawasaki's are 32:1 in the manuals. For these motors, you need to run 20:1 and then 25:1 after break in. Going to 40:1 will burn them up. But they will run great to the point of burn up. Keep in mind, racing two strokes run leaner such at 40:1 even 50:1. But.. The race bikes have their top ends rebuilt every other race too. so.. If you want your engine to run good and last a good long time, run 20:1 or 25:1 with Synthetics after Break in. At 40:1, you were running a mix that racers use typically, and... Now you need a new top end rebuild too. But.. I am sure it ran good up to the point of burn up. anyway.. Either buy a grab bag motor when offered, or buy a new top end and get her going again. And... Run around 25:1 with Synthetic 2 stoke oil.. Enjoy the ride...

 

[thatsdax]

Tommy.. Not a big deal

Tommy.. Not that big a deal. Looks like the cylinder or from what I can see of the cylinder looks ok. Just get piston and ring, maybe a new wrist pin bushing and you should be good to go. Thanks... Enjoy the ride..

 

[Egor]

Hi Duane - I am running one of your econo 65cc kits I got a few weeks ago, I love it. It went good but I could not leave it alone so I did one of my trick port jobs on it, I wish I could let you ride it now. I see you don't like the 40:1 mix, after I brake them in thats all I run, so far I have had good luck. I am an outboard motor mechanic they run 50:1. One thing I always do is take these china engines apart before I run them and see if all is correct, then I do a run in and check for high spots on the piston and the like. I then clear up any miss fitting and finish running them in. I also remove the sharp edges off the rings so they don't scrape the oil off the cylinder, the Chinese don't have time to do that. I ordered the drop tank, an am looking forward to see what I can do with that, I have to dream up a good paint scheme. My buddy Chuck said he had a good time talking to you, he is the one ordering my stuff, I have no Pay Pall. Have fun, Dave
PS: The exhaust port on the 65cc is 1.1" from the top and large, perfect, and it shows in the running.
Question - is the only engine you have with the needle bearing wrist pin the 50cc kit, I want to try one of them next. Oh one last thing, I love the larger cooling fins. (Looks Cool) LOL.

 

[thatsdax]

I am currently updating the 65

The 65 is being updated to roller bearing at the wrist pin as we speak. Should be done in the next 3 or 4 weeks. This was the only weak point on the 65 is the bushing at the wrist pin. There is no way to convert from what I know. the connection rod for the roller is different than for the bushing. Keep an eye on that Bushing. You may want to pull it and have a steel one milled and make your current oil hole larger. also.. I am Beta testing the new Titan 50cc 4 stroke ! So far so good !! This is a 4 stroke with wet clutch. Very cool, very quite, very sooth, and very fast !! As I am getting the 2 strokes up to speed, we are also doing the same for the 4 strokes. The 2 stokes with the roller set up are going to be tough to beat. But..This new 4 stroke is awesome !! I think it may be as fast as the 2 strokes. It is fast for sure.. Simple too. Over head valves with screw adjuster. Made with good steel and strong. Should last a good long time. But.. I am still testing. only 1000 miles or so now. I have around 4,000 on my 2 stroke and that is with bushing. I also have around 1,200 miles on my other 2 stroke with roller. Anyway.. I am rambling on. I am excited about this new 4 stroke. I am loving it. I have the Grubee type from Apple big. I only have 95 miles or so on it. I parked it. It makes too much noise. I have tried wet and dry in the gear box. Wet makes the clutch slip. It did not help the noise much anyway. I have heard others have the same problem with that gear box as well. Not sure what they need to do to make it better. Engine seems good. It is a Lifan or something. Seems to be good quality. but the gear box is not good. This new DAX Titan is there design wise. At almost 1000 miles I could say it is reliable. but..I need more.. I will let you all know.. Enjoy the ride..

 

[thatsdax]

How do you?

How do you remove the sharp edges? Can you explain? Also.. After break in, you go 40:1. What type of oil do you use after break in? Let us know.. Thanks..

 

[Egor]

OK all the expensive 2 strokes never have sharp edges around the circumferences of there rings. Oil control rings use the edges to scrape the oil off in a 4 stroke. What I do is remove the rings and run them at about 45 degrees to honing stone and run upper and lower edges off, this way as the engine is running the rings stay on top of the oil. Also I am using Evenrude outboard oil.
Does the 4 stroke resemble the Whizzer in any way, looks are everything. Have fun Dave
PS: The 65 has a smaller bolt circle so none of the top end stuff from the other engines will fit, Does the new one use the larger pattern? I would like to see this engine converted to a 4 stroke. There is a 4 stroke that takes an oil mix, the intake is connected to the crankcase just like a 2 smoke, it also uses a reed valve, it has a normal exhaust. As the piston comes down it acts like a super charger pushing on the intake valve, we have some in the shop. They sound cool.

 

[Egor]

Duane - Is is possible to see the Titan yet, Or is it too soon? Thanks for all the work you have done to keep the Two Stroke alive. Have fun Dave