Go Go Sundiro! 70cc Stage6 Sport Pro MKII build

[lordverminaard]

Time to add a build thread for my recent acquisition.  I mentioned it in my welcome thread but to recap:

2002 Sundiro Akita with ~1500 miles, owned by a 90 year old man who drove it up until around July when it became hard to start.  The old man died, and his daughter and husband let it sit while they gathered up the man's belongings and sold the house.  I bought it off of them for $125.  The battery was dead but I did kick it a few times, felt like it had good compression but it didn't try to start.  First things first, lets see if I can get it running!

It has the 1pe40QMB engine, which is a bummer as I was hoping it would have the FM but oh well.

Here it is after I brought it home:



I pulled the plug and replaced it, verified spark was good.  Still no start.  Hooked it up to my jump box and cranked while feeling exhaust, felt good pressure coming from it... Time for the shrouds to come off.  Got the airbox off, sprayed a little carb cleaner at the carb and cranked, and it kicked just for a minute but then went back to cranking without any attempt at starting.  Seems like a fuel issue.  The next time I work on it I will pull the carb and give it a quick once-over.  This is where I left off for the evening:




My work time is limited to about an hour after the kid goes to bed so I don't have a ton of time to tear into it but hopefully I can at least ride it around the block before the snow starts flying and then I order a bbk and stuff, lol.

The plan for this thing is to get as much streetable power out of it that I can while still making it easy enough to ride that my Wife could confidently hop on and go and not worry about it.  So I guess that means big bore but not a lot of crazy porting or a super high-strung exhaust.  I might even think of swapping in a 90cc.  Who knows. 

Until next time!
Brendan

[spaz12]

A 70 with a stock-ish pipe can make for a great boost in torque and fun to run around. It'll take a tuned pipe to unleash the speed, but then they sorta become unfriendly to wives.
I think the 90's you get the torque and speed, but I've never built or ridden one so couldn't really say for sure.

[lordverminaard]

Good things to think about.  I am leaning heavily on the cheaper/simpler approach, since I don't really love this scooter and if the Wife likes riding this scooter we will get her a nicer, new one like a Kymco Compango. I could turn around and sell this one in the spring and probably make some decent profit then I could get something I like a little more such as a Zuma or a TGB Keywest.

Anywho, I got her running last night, (didn't have my phone so no pics or a video... yet) all it took was a quick clean up of the carb.  I was surprised to see a real Mikuni carb on it, so the screws were all high quality and the carb was in really good shape inside.  Both jets had a "film" across the orifice, you could see light through them but it wasn't clear.  First time I have ever seen that.  

I fired it up, and decided to go ahead and ride it around the block- at 10:30 at night and about 33 degrees F cold, haha.  Also all the back-half plastics removed and no taillight.  It did ok, it would bog at anything past half throttle, I am not sure if that was because it was so cold out or if something else is wrong.  The front break also squealed so loud I probably scared half the neighborhood, haha.

When I got back I noticed a lot of smoke, so I hopped off and saw that the petcock was leaking fuel all over the cylinder.  Thankfully I didn't set myself on fire but that will need dealt with.  Actually, all the fuel lines, vac line and fuel filter were in such bad shape, it felt like I was working on something from the 70's.  The spark plug boot has a crack, so I will probably just replace the coil/plug/cdi "while I am in there".  Intake manifold also has visible cracks so I should replace that too.  Suspension is REALLY bouncy in the rear so hopefully I can find a replacement shock that will work.  Also, the speedo doesn't work.  Not sure how much of a big deal that is, really.

So far, for $125 plus the cost of a new plug, and about an hour of me working on it, not a bad deal.  I don't know how much longer the weather will hold out so I am trying to decide if I want to replace a bunch of stock parts real quick to make it streetable for any nice days that are left or just not worry about it and start tearing it down.

I'll post some pics or maybe a vid later.
Brendan

[lordverminaard]

Ordered some parts, including a new fuel line and filter kit, "performance" intake manifold and reed valve set, CDI and coil since the stock plug wire and boot are cracked pretty good. Also ordered an ebay rear shock/spring that should fit, and also two smaller front shocks that should fit the trailing link suspension. I realized that when I am sitting on the scoot, the front suspension is about 1/2 an inch from bottoming out, so that if I just push forward on the bars it will bottom. I'm not a small person at 200 lbs, but I don't think it should bottom that easily, lol.

I also called around about the fuel valve/petcock and nobody stocks one for this thing.  Moped World was the only one that did and they wanted $70 for it.  Sheesh, more than half of what I paid for the scooter!  So I went out and started it up again to see where the fuel is leaking, and it didn't leak.   So maybe I will ride it around the block again and see if it leaks.  For reference, this is the type of fuel valve it has:


There is another screw at the opposite side that you cant see in the pic.


So that's where I'm at right now.  It looks like I will probably just tear the scoot down here soon, pull the engine apart and see what I am dealing with and then order the bbk and associated stuff.  I won't touch the variator until I have the engine installed and running then I can tell what I will need to do from there.


Laters!
Brendan

[niz76]

I have gutted out (special order) petcocks and just an on/off valve down the line...



Shameless plug of a BBK for your scoot- if it uses a 10mm piston pin, if not you could order a 12mm piston for it... (makes a nice powerful torquey combo with the stock exhaust!)

49ccscoot.proboards.com/thread/17433/70cc-airsal-minarelli-horizontal-shipped

[lordverminaard]

Dude! That's a hell of a deal. Tempting to just do it and worry about the pin size later, haha.

Let me think about that.

Thanks!

Brendan

[lordverminaard]

Also, quick update, wanted to run it around the block again before it got too cold to see if the hesitation past half throttle went away. Well, I started it up, let it run a minute, no leaking. As soon as I dropped it off the center stand, fuel started leaking again. It was actually the fuel line that had a leak, and letting the suspension settle on the ground bent it enough to make it leak straight up into the bottom of the fuel tank, making it look like fuel was spraying out of the fuel valve. LOL! Good to know I don't need a new fuel valve.

Brendan

[larrball]

You'r not new to the game with your flash's words and working pitchers.



Welcome to the form.

[lordverminaard]

Rode it around the neighborhood today while it was warm for about 15 minutes, going slightly downhill it would haul ass, (since the speedo doesn't work who knows but it felt like at least 40) but on the flat or slightly uphill, it would still bog out at about half throttle. It takes off from a stop with great gusto for what it is. I don't think there is any sense in spending time trying to solve the bogging issue right now, I think I will commence teardown here soon and start fresh. I found the original owners manual in it, so looking through the specifications, the manual says it has the 1E40FM engine with the proper bore/stroke specs in the manual, even though the engine stamp has 1pe40QMB on it. So who knows what it really has, I guess I will find out when I pull it apart.

My first round of parts are due in this coming week so I might swap out the shocks just to see how it feels but after that I'll start tearing it down and cleaning stuff up.

Fun fun! I am very excited.

Brendan

[lordverminaard]

Got to work on the 'ol Akita tonight, after about a half hour of cleaning up the garage and workbench, I got started on pulling the engine- 15 minutes later, we are here:







No surprises really, it was pretty easy. I kinda had to lay over the seat with a wrench in one hand to hold the main engine mount bolt while reefing on it with another wrench from the other side, it was TIGHT. Scooters are fun to work on, after everything was disconnected, I just lifted it off the engine and set it on a paint can and tossed the engine on the workbench.

Pulled the variator cover off, (each screw requiring an impact driver!!! ) and it looks like nothing has ever been touched under there. Everything was pretty clean, no signs of anything crazy happening, and even the gasket was intact. I didn't have a lot of time left at this point so I got a quick measurement of final drive ratio, almost 11:1 exactly. I really wanted to pull the head tonight and measure stroke to see what engine I actually have in here but it was getting late. Maybe tonight I can get to that. Here's where I left off:



Some other interesting things. This has a non-cable actuated oil injection pump. I don't want to use pre-mix so maybe one of those adjustable oil pumps is in my future. Also did some measurements around the suspension, and it looks like I can run a 3.5x10 tire instead of the stock 3.0x10 pretty easily. Might even be able to get a little bigger than that in the rear if I shim the hugger fender a little. But I will probably just order some 3.5x10's for now and see how it does. I am also going to take a lot of the body panel hardware and the variator fasteners to the local hardware store and get some Allen caps to replace the Phillips head screws which will make variator tuning a hell of a lot easier.

I will also have some decisions to make once I find out what engine I have. If I do have the FM-style engine, it would make sense to split the case and put a larger crank in there just because it would be very simple to do so. If not, I still need to decide if I want to split the case to replace bearings, or put a higher performance crank in, and do some case porting. Time (and budget) will tell.

Finally, some bad news, I have been diagnosed with pretty severe carpal tunnel syndrome in both wrists. It has been a condition that has been bothering me for many, many years but I have always been afraid to do the surgery since I have heard the recovery is tough. But it is getting bad enough that I am loosing a lot of functionality in my hands, and my hands are my life- I work in IT so I am always at a keyboard, I am a musician which requires a lot of hand dexterity, and I wrench on cars, bikes, and now scooters for a hobby and I can't give that up. Plus my Son is 2 years old now and will be getting old enough to start "helping" daddy with his projects soon. I had a recent Electromyography test and the Neurologist said that I am to the point where permanent nerve damage can occur if I let this go much longer. All that being said, I will probably have one hand done before the end of the year (insurance reasons) and possibly the other toward late winter/early spring, so my wrenching time might be put aside for a while. I'd like to get as much of this done before the surgeries start. I've been told that during recovery I could use the hand but my gripping strength will be very diminished for a while. So I will play it by ear and keep the thread updated with that. All I know is, just from the small amount of light wrenching I did last night, I had trouble sleeping and my hands have been burning all morning and it has taken me quite a while to type up this post, haha. I guess I must really like working on old crap.

Thanks and sorry for rambling.
Brendan

[lordverminaard]

Got a little more work done last night, after tearing the head and cylinder off, it looks like this is indeed a normal 1PE40QMB and not the FM engine.






Head even has a little Sundiro logo on it, lol:



And here is what the specifications in the manual said:



So with that being established, I have to make some decisions as to how far I want to go.  I can slap on a new big bore cylinder kit and run with it, or I can split the cases and put a better crank in and do some mild porting and replace bearings and such.  I guess the common denominator is that winter is basically here (even though I rode the Ducati to work today, 72 degrees!!!) I have time to do either one, the only variable is time required and additional parts cost.  So I can mull over that while I work on other aspects of the scoot, like suspension.  Got my replacement front shocks in, they are really stiff, I can't compress them by hand but the original dampers are so worn that I can basically compress them with little effort.  I do need to source or fab a small spacer/bushing since the non-threaded hole in the lower shock mount is slightly larger than the OEM one.  Otherwise they will fit perfectly.  They should look nice too!


Probably won't get around to much else other than parts gathering until after the holidays so it might be a while before another update.  Time to start shopping around for a cylinder.  I'd like an aluminum one if I can find it but we'll see what comes up.

Thanks,
Brendan

[190mech]

If the crank looks OK,find a quality sport 70cc kit,Dell carb,pipe,and have fun!
www.ebay.com/itm/Performance-Aluminum-cylinder-70cc-kit-Dinli-50cc-Dino-50-2T-50cc-quads-/331954972822?vxp=mtr&hash=item4d4a0ee896

Be sure to check your piston pin size,and get a kit with matching head...

[lordverminaard]

I like that plan. Simple. Any pipe recommendations that won't wake up all the neighbors? Also, 19 or 21mm Dellorto? And are those "clone" Dellorto carbs any good or just junk?

Thanks for the input!

Brendan

[190mech]

LeoVince seems popular,many others though,,The Dell clones work fine,just need a teardown when new to clean,Cruise the tech section for lots of info..Also Brent had a looong thread on "project50" in the build section..

[lordverminaard]

Time to drag this thread back up with an update now that spring is almost here. (even though it is supposed to snow tonight, and it was 72 yesterday, WTF Ohio???)

I put my Ducati up for sale, I love the bike but I am not "in love" with it, that will free up some funds too.

Finally bought a carb for my Sundiro, one of the Dell clones on ebay, a 21mm variant:


I tore it down to see what's inside, the needle wasn't marked but from measurements it looks like it is a W16, so I will probably order a W7 since that is what everyone recommends. Floats were set correctly, it had the correct 2-stroke 262AU Atomizer and 9655 bushing, yay! 90 Main jet, 60 start\choke jet, unknown pilot jet. Slide is also unmarked but it has a cutaway bigger than any that I have seen pics of on the internet so I will probably need a new one of those as well, seems that the 40 is the one to have and if I need to I can file it down to a "45".  Need a 90 degree throttle cable top and some sort of remote choke lever so I can mount it on the plastics under the seat.  Managed to find a piece of 1" rubber dishwasher drain hose that fits the outlet of the carb perfectly and allows the boot on the fancy intake manifold I have to fit snugly too. The manifold came from ebay but it looks like a clone of the popular NCY manifold with two vac\boost nipples on it. The inlet side of the carb has a nice plastic screw-on velocity stack and it fits the hose from the airbox no problem. I like it with stuff comes together.

After a lot of research I will probably go with the Stage 6 Sport Pro 70cc kit and more than likely a Stage 6 Pro Rep pipe. Lots of people run that setup, and some of the tuners out there have gotten a ton of power with them with additional tweaks. Also at the price point for them, I am not sure there is anything else close in the aluminum cylinder class.

Got my tires too, Kenda K413 in a 3.5-10. Also got the front shocks installed after fabbing up a quick spacer.

I also have just about everything torn off the engine so that I can clean it. No surprises, everything came off without issue. I was even able to get the flywheel off without a special puller, used my jaw type puller and it popped off easily. I will modify the stator to get adjustable timing "while I'm in there".

Sorry there aren't more pictures, the last few times I have worked on it, I didn't have my phone with me. Once I free up some funds the work will really start.

Until next time!
Brendan