Project 90 (Stock 89cc And Beyond)

[90GTVert]

Repaired And Ready To Continue Testing


After the circlip failure in the last update, I picked up a new piston kit.




The kit came with the circlips shown at the top of the image below, but I used a set of circlips as shown in the bottom of the pic for assembly. It would be a good idea to use a bit of loctite on either style for added peace of mind. I used nothing. As much as I don't want another engine failure, I'd like to see if I have better luck with this style of circlip installed just as the others were.




I used a ball hone to hone the cylinder. As the pics show, I still have gouges in the cylinder wall, but it should be alright.






The head suffered some damage, but I cleaned it up and it can be re-used.






I put everything back together and verified that squish clearance, timing, and compression were all where they should be. Just as I thought I was ready to resume testing, I started having problems with the electrical system. To make a long story short, I ended up making a complete custom wire harness for this scooter and all is well now. Project 90 is back on the road.

[90GTVert]

Phase 2 : Phongeer Exhaust

The next pipe on the list to test is the Phongeer exhaust. This exhaust was tested in phase one of the project, so you can check that out HERE to see pics, video, and installation details.


Tuning the scooter after installing the Phongeer exhaust with the Phase 2 setup required a bit more effort than past pipes or this pipe on the otherwise stock setup. Jetting did not change. It runs well with the 90 main jet, just as the baseline did with the stock pipe. I spent quite a lot of time swapping up and down on main jet size and changing needle positions though. I did this because I had a rich stutter or bog at times trying to get to WOT. I ended up swapping from 1500RPM clutch springs to 2000RPM clutch springs. This helped the engine get past the dead low rev range faster, that I think the pipe is accentuating. No change was necessary to the roller weight. After installing the clutch springs I settled on moving the needle to the next to leanest (from next to richest) position for best results and re-adjusted the mixture screw. There is still a slight sputter, but nothing to be concerned wit. Essentially if I open the throttle all the way, quickly, from a stop, I get about two to three quick sputters (pop pop pop <please forgive my sound effects) and off it goes. This happens in a split second now, but before the clutch springs and needle position change it was quite a severe bog at times.


I took P90 out for a 31 mile test ride and managed 50.11MPG. Wide open cruising speeds ranged from 50-55MPH in most conditions. The faster you go with limited power (like a scooter), the harder it is to maintain a constant speed. Max speed increased 3MPH over the baseline to 61MPH. Project 90 has finally broken the 60MPH barrier! Maximum RPM observed was just shy of 9,200RPM. The Phongeer exhaust definitely likes to rev a little more than the previous setups, but power is increased anytime above 6 or 7,000RPM greatly. This pipe, coupled with the other modifications for Phase 2, is the first time that Project 90 is really beginning to feel like a 90cc should in my opinion. Strong power throughout the throttle. There's no need to go WOT or anywhere near it to get a strong start and it doesn't take much throttle to cruise unless you want to cruise fast. I believe this is why the gas mileage showed a little improvement over some setups.




I really enjoyed riding for this test. I believe this could be an excellent, reliable, setup for someone that enjoys riding reasonably quickly. If you ride even slower than I do, you could probably see better than 50MPG, which isn't bad for a 90cc 2T. It's plain enough and quiet enough that it doesn't draw much attention as well, so it's a great choice IMO. The porting on Phase 2 of this project is actually tailored for a bit higher revs than this pipe is meant for, so with porting to match I think it could be even stronger.

[90GTVert]

We might have the first ever SSBIDNT. That's... Sucks So Bad I Did Not Test. I bought YMS V8 some time ago to test in this project. It seems like a pretty popular pipe and it's easy enough to find on eBay at a good price that I though it would be a nice addition to the project and a nice addition to my current selection of pipes. I really like the PG pipe, and the YMS V8 is supposed to be somewhat similar.

Well, the fit is terrible to say the least. I had one hell of a fun time trying to get the pipe to seal at all. I eventually used the thick gasket it came with, coated with RTV, and finally got it to seal. Once it sealed, it sits in this position.



Just to be clear, the shroud is not keeping this from bolting up, that's where it has to sit for the header flange to line up well enough to seal.



Even if you don't think sticking way out and pressing on the fan shroud is a big deal, it won't bolt up. The pics below show how the bolts want to line up. The top bolt is so far forward that I would need to cut part of the shroud away in order to get a bracket to fit (shroud is unbolted and pushed forward a bit in the pic). The bottom bolt isn't too great either.






If you're thinking, no problem... I'll just cut that bracket off and make my own from scratch, there's more. It also runs into the center stand with it on the stand. I had to put the scooter on jack stands to prop it up for installation so I could make it line up right to finally seal. The stand can be used, but it's definitely not an ideal fit.






I've heard of enough other people using this pipe that I'm thinking I must have got one with something off about it. Either that or there are a lot of scoots out there with poor fitting pipes. Short of chopping the stock bracket off and making a new one, I really have no way of getting it to fit well at all. Even then I don't like it hitting the stand. I'm not sure exactly what I want to do at the moment, but I'm less than pleased with my V8 at this point.

[stepthrutuner]

Oct 7, 2011 15:28:11 GMT -5 90GTVert said:

I really enjoyed riding for this test. I believe this could be an excellent, reliable, setup for someone that enjoys riding reasonably quickly. If you ride even slower than I do, you could probably see better than 50MPG, which isn't bad for a 90cc 2T. It's plain enough and quiet enough that it doesn't draw much attention as well, so it's a great choice IMO. The porting on Phase 2 of this project is actually tailored for a bit higher revs than this pipe is meant for, so with porting to match I think it could be even stronger.

[/center][/quote]

Sounds like the experimental learning/teaching project might stay on hold for a while since you've missed so much seat time lately. :spin: :riding: :spin:

50 mpg ain't bad, buddy. :nana:

[90GTVert]

Na, as you can see the pipe came straight off and I went on to the headache of the V8. I did enjoy getting on a scoot I didn't expect to break down again, but a lot of what I enjoyed was also the project having the kick that a 90cc really should. Pulling out on a 50MPH road and realizing you're keeping up with traffic rather quickly. ...And all of that with a scoot that seems like little more than stock from the look and sound of the engine (granted T2 is kind of an odd duck and draws it's own attention lol). The plan was to put the V8 on and tune it and maybe get to Ocean City, MD for the big fall hot rod show going on right now. So much for that idea. Who wants to ride on a beautiful day when a bunch of muscle cars are out when you could sit at home with granny like every other day anyway? :spin:

[stepthrutuner]

:lol2:

[byte]

how sad....

i like the sound of those v8's, how it screams on higher rpms.

[90GTVert]

Phase 2 : Leo Vince ZX


Next up, the Leo Vince ZX. I tested this pipe in the first part of the project as well, so click HERE to see more details, pics, and video of the Leo Vince ZX 100cc in action.


I moved up to a 92 main jet and put the needle next to the richest position. It felt a little bit too rich at part throttle at times, but I got a lot of detonation at part throttle at higher speeds and the richer needle setting seemed to help that just a little bit. Throttle response was good, so I had no problem setting it slightly rich at part throttle. I stuck with the 2,000RPM clutch springs, as used on the last pipe test with good results.


I noticed a lack of RPM compared to what I was expecting. I had been seeing the revs hanging around 8,500RPM with the 6g sliders the previous setups used. I used to use this pipe with my first 90cc setup and it ran strong up near 10,000RPM, usually seeming to run strong until about 9,700 or 9,800RPM as I recall. I moved to 5g sliders and saw just over 9,000RPM, but it felt like nothing was there after 8,800 or so. I moved to 5.5g sliders and the revs would hang around 8,600 to 8,800RPM most of the time I was full throttle and that seemed to be the best option.


I rode 34 miles and saw only 39.7MPG. This is far below some previous tests. I must admit I was quite hard on the scooter, spending the majority of the ride at WOT or close to it. WOT cruising was good for 50-55MPH. I saw a max speed of 58MPH. I found this pretty disappointing considering the baseline for Phase 2 with the stock pipe was 58MPH and I've seen as much as 61MPH so far with the Phongeer exhaust. I might have been able to tuck down for a little longer and find an extra MPH, but the power just isn't there when I ask it to rev a little higher. My RPM was around 8,900 at top speed.





Acceleration felt good. Throttle response was good. Cruising speeds were good. All of that said, it just feels like something is missing. I know this pipe has more in it. At this point I am inclined to believe that without a larger carburetor this engine just isn't going to run as it should when attempting to rev it into the 9,000RPM range. When I ran my other setup in the mid 9,000 rev range all of the time, it had a 24mm carburetor. That's a full 10mm larger than the stocker being used on Project 90 right now.


The ZX still made a nice improvement in acceleration and power up till close to 9,000RPM, but if I had to choose a pipe for this exact setup it would not be the Leo Vince ZX.


Since I was able to get out for a brief ride during the day for a change, I took the GoPro along and made a little video to show you how Project 90 is doing at the moment. Check it out.

[190mech]

Cool Vid!Did the LV ever "hit" or "get on the pipe"?I would think a full expansion chamber would make it pull much harder than mufflers..

I get confused with all the combinations,,dont you have a 'mod chart' somewhere?? :stumped:

[jmkjr72]

the zx isnt a true expansion pipe it hs baffels in the pipe
and if you remove the baffels the geometry isnt right you need to shorten the header pipe and tweak a few other things to get a tip top pipe

[190mech]

Yeah,Ive got measurements for a few of their models,whackey angles and dimensions!I think its more show than go!!

[90GTVert]

It does hit and pull well, but it just can't get the revs up to where it did on the other setup. This pipe has had the header opened up and the baffles removed. It has ran very well on other setups. I've gone just over 65MPH with this pipe on a similar engine/trans but with a 24mm carb. It has more in it, but it's about 1000RPM shy of where it would be on that setup. It's like it runs hard right up till that cutoff around 8,800RPM and then it just says, "nope, that's all you get" and making it rev past there just feels empty.

As far as the combinations... I tried to make it as simple as possible to follow, which is why this is called Phase 2. Phase 1 was essentially trying a mod a time on a stock motor. This is the rebuilt motor (remember the crank went and I got a 45mm crank from an ATV, so it's 96cc), ported cylinder, Hoca vari. The fastest way to find all details is the condensed version of this thread in the Tech Library. All of the details of Phase 2 are on this page...

49ccscoot.proboards.com/index.cgi?board=yamajog&action=display&thread=1712&page=3

[Fox]

I like the vid! I think you should quit while you are ahead and just ride it for a while. After all, isn't that the fun part? It hauls butt and it seems reliable (knock on wood)

[90GTVert]

Can't do it. Must experiment. lol

[190mech]

YES!There are Mad scientist laboratories all over the country!! :zap2: