GEN IV dax build and review

apex said:

I have a new dax motor as well. I developed a sqeak after about 200 miles. I isolated it to the clutch to sprocket shaft assembly. I pulled the sprocket cover removed the small bar and yes, there is a ball bearing inside shaft. I greased it up good. I also removed the cluth cable perch on the motor casing and pushed some grease in there as well.

The squeak is gone, for me.

Here is Happy Time Harry.


Good luck finding yours.

I too am quite pleased with this motor. Mine is still bone stock, for now.

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Nice looking bike apex..... I like the rear mounted tank also, trying to figure out for sure what it is, looks kinda like a coleman cook stove fuel tank but cant tell for sure, whatever it is it looks like its doing a great job.

Map

Larger jet sounds like the right direction to go. You increased the air flow and increased exhaust flow, therefore you must increase fuel. What oil mix are you going to run?

That plug color looks good to me, I run my plugs that color or lighter with 100:1 Opti2 mix, very little four stroking at any rpm and runs cool as a cucumber on long wot runs......

Superior lubrication that I get with Opti2 is my recipe....... to much oil in the mix lenss the fuel/air mixture so a well tuned carb and 100:1 with a superior lubricant like Opti2 is a great combe for performance and engine protection in my experience, people that aren't running it just dont know what they're missing out on for sure.

Map

mapbike said:

Nice looking bike apex..... I like the rear mounted tank also, trying to figure out for sure what it is, looks kinda like a coleman cook stove fuel tank but cant tell for sure, whatever it is it looks like its doing a great job.

Map

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That tank is a windshield washer fluid reservoir from a 1970 VW bus. They were a pressurized vessel so its quite stout. Gas doesn't react with whatever its made from either. My peanut tank didn't last one fill before leaking.

I'm thinking about trying my hand at fabricating a small copper tank. I have a slip-roller and a metal shear at work, I've brazed pipe before, for plumbing purposes, so I figured Iwould give it a go. I ddon't know how to tackle the filler neck/cap assembly, so I may just use an-fittings.

On another note, how do you like the upgraded carb you put on the dax? I'm considering it myself, not sure which jet range to go for.

I am currently running a #64 jet from sick bike parts using opti 2 mixed 100:1. Amazing results with it. Smokes only while it's cold. My plug chops are a gray and my ports/cylinder crown is spotless. Previously I posted saying to go up a jet size but that was before looking at your pictures. I suggest starting with a #68 jet and do several plug chops before jumping to another jet size. It takes several miles of riding to get accurate plug readings. I lost my entire summer of riding to carb tuning and playing with oil mixes ratios because of inaccurate plug readings. My best advice is to choose an oil mix and stick with it and tune your bike to run that mix. I have a long thread on here breaking down my experience tuning my bike to run several different mixes and settling on opti 2. Opti 2 is made locally where I am located and I've never heard a single complaint.

apex said:

That tank is a windshield washer fluid reservoir from a 1970 VW bus. They were a pressurized vessel so its quite stout. Gas doesn't react with whatever its made from either. My peanut tank didn't last one fill before leaking.

I'm thinking about trying my hand at fabricating a small copper tank. I have a slip-roller and a metal shear at work, I've brazed pipe before, for plumbing purposes, so I figured Iwould give it a go. I ddon't know how to tackle the filler neck/cap assembly, so I may just use an-fittings.

On another note, how do you like the upgraded carb you put on the dax? I'm considering it myself, not sure which jet range to go for.

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I really enjoy the added low and midrange performance increase with the RT Dellorto clone carb, it's much more responsive than the NT carb on my engines, I'm using the shorty manic mechanic type intakes on my engines that are running the RT carbs.

Dax has a great deal on the carbs, cable and filter.

Just a note: the throttle cables that dax has cor the RT carbs needs a very minor mod before it will work, the small barrel shaped end that goes into the flat slide in the carb needs to be either filed or ground down so that it's about half the length it is when it comes from dax, simple mod but has to be done or the cable wont fit into the slot in the slide so that the slide will have full range of motion .

Map

rogergendron1 said:

that carb is nice but its only 15mm i like along the lines of 16mm pluss usualy between 16 - 19 mm

if i was going to keep my motor stock or near stock motor that rt carb would be a great option ! but i already have ported it for high flow and high rpms and run a free flowing custom exhaust and have a light piston and piston mods, and the motor needs a bit more fuel flow from a larger carb for it realt benifit, it would make no since to get sutch a small carb and only have to upgrade later.

i am actually in the market for a new USED miuni vm 18

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Well its a "to each their own" situation on what carb one wants or needs for that matter, my engine is heavily ported and im getting over 9000rpm and a top speed of 45.3mph with th RT carb and very good power in the upper low to mirange rpm range all the way to top cruise speed, unless everything is just right even a bigger carb wont get a person any better power or cruise speeds, as far as top speed, I've hit 45mph with the little NT carb it just doesnt perform nearly as well in the low to midrange as the RT does.
If a person isnt careful they can do what I used to see people do back in my hot rod days and end up with an 850cfm Double Pumper on a mild 283 smblk which will not perform as well as what a 600 or 650cfm rated carb would do on that platform, the larger carbs are fine for real high flow china girl builds and there is some extra speed to be gained if tuned correctly and the entire platform is built to handle the added fuel and air supply, but in my experience what most of us do to our engines ranging from mostly stock all the way up to good porting along with a few other mods, the RT Dellorto clone carb fits the bill in an excellent way for a very broad range of china girl builds, it just simply does a great job of added performance in the area of throttle response and noticable torque and midrange improvement even on a bone stock engine and still performs great in the rpm range of 9000+rpms which is highr than most people engines will ever see.

I plan to experiment more with some other size carbs in the future, but for 95%+ of most builds im gonna say the RT carb well tuned is still the best bang for the buck.

Map

rogergendron1 said:

ok i am painting up the case bolts so they POP out and painting the long intake and swaping over to it, i want the larger dia boar and believe it will offer better flow, also started with the first coat of paint on the fins, and cleaned up and rebuilt the carb.

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I must say I'm quite impressed I liked the bare metal look on the fins better than the orange paint on them.

For some reason the orange paint on the fins makes it look like rust at first glance.please note I mean no disrespect to your awesome project sir!

Good thread. Read it all. Learnt some things , and going to try some of them.
Especially that 100:1 oil . i found a dealer close to me. Going to try some, I will let you know what I think about it.

powerbike said:

Good thread. Read it all. Learnt some things , and going to try some of them.
Especially that 100:1 oil . i found a dealer close to me. Going to try some, I will let you know what I think about it.

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Best wishes and enjoy the Opti2 100:1 mix, its all I run now and wont go back to anything else....

Map

rogergendron1 said:

ok here is inside the case and the clutch disk looks to be made of a much higher quality steel than the grubee motors soft plain steel one, all else looks in order !

the piston marked up for ramping and cutting

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How come you didnt do the exhaust port also?

Gray or alloy color appears on the tip of your plug from excessive heat and some cook off of your alloy piston putting alloy or gray deposits on to the tip of your plug. A lean condition.. If you are a racer and rebuild after every race, this can be acceptable since lean and mean is the way to win just short of a piston melt down. For the every day rider looking for a long life engine needs to be looking for a toasty brown color on the plug chop.

thatsdax said:

Gray or alloy color appears on the tip of your plug from excessive heat and some cook off of your alloy piston putting alloy or gray deposits on to the tip of your plug. A lean condition.. If you are a racer and rebuild after every race, this can be acceptable since lean and mean is the way to win just short of a piston melt down. For the every day rider looking for a long life engine needs to be looking for a toasty brown color on the plug chop.

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Right on.....!

So Roger whats your top speed with this motor? I'm contemplating this motor or a GT5