98 Elite S Big Bore problems

[veedubh20]

50mm bore kit is not bolt on, because boost port is bigger, Lot of time, riders seize piston, because of blockage boost port on the case.. Better off get polini contest a or corsa.

[ped-city]

Boost port???

I just emailed vtcycles.... hope to receive a reply and get the ball rolling on a new bbk, carb setup, air filter, and exhaust set up for some sort of a kit they may be able to help me with... I'm not one the likes to mix and match parts...

[808BMW]

The exhaust is of an 89 250R 2stroke. I was thinking of using the stock header pipe that curves around to the stock muffler and cutting it there...

What all else have you done with that 50mm kit as far as exhaust, carb, and air filter? What's your top speed?

Still sounds way too big, you're trying to throw a 250cc pipe onto an 80cc bore... I just pulled the muffler off my yz250 dirtbike and that thing is an animal, definitely way too big for a moped.

I run a 24mm carb, no filter, and varying exhausts. I can do around 58mph with my stock muffler, and 65+ with a racing exhaust, but I have very long gears (6.9:1). P.S. stock, uncut boost port.

If VT doesn't email back, you probably have to give them a call, don't forget to account for the time zone difference in Hawaii.

[eliteguy50]

Boost port??? ...

The intake port at the back of the case that comes up to the cylinder. The af16 has a smaller port than the BBK (designed for true dio which we never got in the states).

[JJ Joseph]

50mm bore kit is not bolt on

I've used this 80cc BBK, and it was a simple bolt-on, except for the jet tuning afterward (use a 90 jet), and altering the cooling shroud. Note that you'll need a Dio or Elite SA50 high-rate oil pump, not the fixed-rate SA50P oil pump. If you've got the regular SA50 Elite, or a Dio, you won't have any problem with oiling. The kit is available for $99.00 here http://www.jiangwayne.com/scooter/p_i.php?i=13. Top speed will still be about 40mph, but with a 17mm belt and a new variator, it should get you 50mph with the stock muffler. The exhaust port on the new jug is bigger than stock, so a new exhaust system that matches the exhaust port will give you another 10mph (about 60mph). If you're short of cash, you can stay with the stock exhaust while you save up for the upgrade. It won't hurt anything.

[Trafficjamz]

50mm bore kit is not bolt on

I've used this 80cc BBK, and it was a simple bolt-on, except for the jet tuning afterward (use a 90 jet), and altering the cooling shroud. Note that you'll need a Dio or Elite SA50 high-rate oil pump, not the fixed-rate SA50P oil pump. If you've got the regular SA50 Elite, or a Dio, you won't have any problem with oiling. The kit is available for $99.00 here http://www.jiangwayne.com/scooter/p_i.php?i=13. Top speed will still be about 40mph, but with a 17mm belt and a new variator, it should get you 50mph with the stock muffler. The exhaust port on the new jug is bigger than stock, so a new exhaust system that matches the exhaust port will give you another 10mph (about 60mph). If you're short of cash, you can stay with the stock exhaust while you save up for the upgrade. It won't hurt anything.

JJ, you have a af18 engine, the af16 requires that the boost port be enlarged.

Why would you tell people that a top speed of 60mph could be reached with a new pipe and belt change.

The only way you could get 60mph is with a gear change to go with the bbk.

And another thing....there is no such thing as a "fixed-rate sa50p pump"

And you will have a problem trying to run a 50mm bbk for any amount of time without premixing some oil in the tank to go with the oil pump.

Quit giving such bad advice.

[ped-city]

^^^^^^^^^^

Btw, vtcycles IS OPEN.

will be ordering all new parts from him. Seems very knowledgeable.
New 72big bore
New jet kit
And anything else I might need ill be ordering from them.
Very reasonable shipping prices as well!!!

[Trafficjamz]

^^^^^^^^^^

Btw, vtcycles IS OPEN.

will be ordering all new parts from him. Seems very knowledgeable.
New 72big bore
New jet kit
And anything else I might need ill be ordering from them.
Very reasonable shipping prices as well!!!

Roller weight tuning pack
Clutch center springs 1k or 1.5k
Clutch grab springs (For a quicker launch)

If you decide to get gears , remember to buy a transmission gasket.

[JJ Joseph]

Quit giving such bad advice.

Sorry you're having such a hard time digesting all of this. The AF18E & the AF16E are identical except the US AF16E is just slightly detuned (older SA50 carb, airbox, and muffler) and made in Mexico rather than Japan. Engine parts are totally interchangeable. An unrestricted Elite S or R engine can be turned into a Dio clone just by changing the intake and exhaust. But you have to be more careful with the restricted Elites. There's 2 kinds of restricted Elites:

* Restricted SE50P capable of 30mph
* Heavily restricted (25mph) SE50P sold in Iowa and some other states.

Some of these are real dogs. Besides being air-choked, their oil pumps are fixed at a low rate of flow, and they have a low-speed final drive ratio. Maybe that's what you're thinking of. It's a free country and you can drive your Elite on pre-mix if you like, but don't dismiss the Dio oil pump set-up. It's a really clever device. The variable rate set-up has plenty of oil for an 80cc BBK. If you're nervous, just turn the adjuster to increase the oil flow over the 50cc rate: increase the flow til it smokes, and then back off a bit. There's lots of them on the road, easily capable of 55-60mph, check them out for yourself. If there was any problems with them, we'd have heard long ago.

[Trafficjamz]

The AF18E & the AF16E are identical

Not true, the boost port is much larger in the af18e

Some of these are real dogs. Besides being air-choked, their oil pumps are fixed

No SA50 or SA50P has a fixed pump. The SA50P has a variable oil pump, but no split throttle cable to hook to it.

The variable rate set-up has plenty of oil for an 80cc BBK.

Also not true. The sa50 oil pump opened all the way can deliver oil at a 50:1 ratio at best.
32:1 or at the very least 40:1 seems to be the norm on 72cc and bigger.

There's lots of them on the road, easily capable of 55-60mph, check them out for yourself. If there was any problems with them, we'd have heard long ago.

I know what speeds dios are capable of ...........(my 50mm bore would embarrass your dio in a drag race)
Just quit telling people that it is possible on stock gears

[eliteguy50]

Don't some of the af18 engines have a different crank or case opening?

[Wheelman-111]

Greetings:

JJoseph incorrectly asserts:

Sorry you're having such a hard time digesting all of this. The AF18E & the AF16E are identical...

They're really not, Dawg! The boost port on the 18 is twice the size of the 16's. If you try to mount a Dio Big-Bore kit on a 16 block, you will leak massive air. The 16 cases need to be gutted, reassembled and the boost port enlarged using the 18 gasket as a template. Absolutely NOT "bolt-on". There are bearing/seal size and maybe crank diameter differences in various years too. If they were "Identical" they'd both have the same AF number. They're not! Jamz is indelicate but correct. Please watch what you assert as fact to the Noobs.

...except the US AF16E is just slightly detuned (older SA50 carb, airbox, and muffler) and made in Mexico rather than Japan

. This part may be true.

Engine parts are totally interchangeable. An unrestricted Elite S or R engine can be turned into a Dio clone just by changing the intake and exhaust.

(Emphasis added.) This part is NOT!! See above. Also the tranny covers can feature one or two NTN bearings, on the AF16 it came both ways. Double '94-early '98, single late '98-2001. Axle shafts have to match the cover. I've read about some AF18s being the same way - some single, some double-bearing. I can't confirm that directly.

The take-home message is that if you're buying a Taiwanese BBK for your AF16, you must plan on splitting the cases to match up the boost ports.

Sanjuro, Bakaracer and others have owned multiple examples of both engines. Anyone seeking to know about parts interchangability should consult one of them.

[JJ Joseph]

The take-home message is that if you're buying a Taiwanese BBK for your AF16, you must plan on splitting the cases to match up the boost ports..

My new Taiwanese BBK was a simple bolt-on. No dis-assembly of the crankcase required. NONE! Just took off the old jug and put on the new one. Done in 3 or 4 hours. Maybe up the oil pump output adjuster slightly to compensate for the bigger bore. I've attached a photo. Just stick that there jug in the hole and bolt it down. You'll be on the road in a couple of hours - at 60mph after a few mods to the belt & pulleys. Total cost of the BBK: $99.00

[Trafficjamz]

My new Taiwanese BBK was a simple bolt-on. No dis-assembly of the crankcase required. NONE! Just took off the old jug and put on the new one. Done in 3 or 4 hours. Maybe up the oil pump output adjuster slightly to compensate for the bigger bore. I've attached a photo. Just stick that there jug in the hole and bolt it down. You'll be on the road in a couple of hours - at 60mph after a few mods to the belt & pulleys. Total cost of the BBK: $99.00

So Your saying, I can take a stock US 2000 elite S:
1. spend $99 on this 50mm bore
2. bolt it on with no mods to the case
3. switch the belt from stock to a 17mm wide one
4. tweak the oil pump.
5. modify the pulley, and do nothing to the gears

And I can go 60 mph

Is that really what you are telling me?

So this is normal? I shouldn't worry about this.


Gobs and Gobs of Bad advice

[808BMW]

Wow JJ, you are spewing out lots of misinformation. Care to post a pic of this adjuster on the oil pump? I've never heard of or seen this adjustable oil pump. Or better yet, just post up a video of you doing 60mph on a stock geared dio block.

As far as the boost port goes, yes it does bolt on without any case mods. I still have a stock tiny boost port on my block, with a huge 50mm bore on top of it. Sure, matching the boost port would be nice, but I didn't do it.