Eton beamer PN2 performance build.

[proy]

Hey guys. So I recently acquired a firts generation eton beamer with under 300 miles on the odometer. Put about another 200 miles on it (according to the factory odometer) and ended having an ignition issue that I have been chasing for the better part of 2 months.

Long story short I ended up ordering a naraku 50cc topend and a naraku crank with new bearings and oils seals. I had come to the conclusion after a compression test yielding under 80 psi that something was wrong mechanically between the topend or crank.

www.scootertuning.ca/en/cylinders-50cc/1042-cylinder-kit-naraku-50cc-10mm-minarelli-horizontal.html

www.scootertuning.ca/en/crankshafts-sport/2054-crankshaft-naraku-hpc-10mm.html

www.scootertuning.ca/en/product-home-scootertuning/2051-crankshaft-bearing-polini-hq-minarelli.html

Once I received the parts I assembled the topend onto the engine without replacing the crank to do another compression test before going all the way to the crank. With the new topend compression reached 123 psi average between 4 tests. So I decided against replacing the crank right now and will save it as a spare for the future.

I check spark after the compression test and although I did have spark it seamed very weak. New plug, had already chased the entire harness, new coil, signal from the pickup. Everything checked out and again was right where I started.

Orderd a new factory eton cdi off of eBay over $90 shipped... Ouch.

www.ebay.com/itm/254907633655?hash=item3b59adcff7:g:M3AAAOSwmSpgU6ze

After installing the new cdi yesterday and struggling with the built in rev limiter. I ended up needing to cut both green wires that are exposed on the cdi under the rubber boot. After doing so everything ran smoothly.

Did some basic tuning over the course of 17 miles yesterday up and down my road before thunderstorms rolled in.

This afternoon I put on another 24 miles on a short trip out of town and back. At the halfway point I attempted to adjust the high end mixture since I had noticed a slight breakup in the high end while riding. Backed the screw 1/4 turn out and made a half throttle pass downhill and the breakup occured lower in rpm and I think it was detonating so I killed the ignition.

Pulled off and went a 1/2 turn back so a 1/4 turn back from original position which ended up closing the mixture screw almost completely. At this point I realized my carb needs to be upjetted to safely continue running the engine. I limped it home under 1/2 throttle.

When I bought the moped it had a really shitty pod filter stuck into the rubber airbox hose with no airbox. So I replaced it with a better pod filter I had around but I suspect its the main culprit for this lean condition. I plan on ordering a new airbox and a good selection of jets to continue with the project.

Will be posting more as I progress further along. I currently plan on maintaining the 50cc bore until I can afford to dig into the CVT and buy a nice pipe that works well for whatever big bore kit I end up using.

[proy]

So update on my first gen eton beamer.  I ordered a temp and tach gauge. 

www.amazon.com/RunLeader-tachometer-thermometer-snowmobile-waterproof/dp/B01KSQY0GU/?_encoding=UTF8&pf_rd_p=401d07bb-1512-4937-8e79-12efae3f0ee6&pf_rd_r=G00FWQMDSZQA033KW94W&pd_rd_wg=HpAUS&pd_rd_w=YIldb&pd_rd_r=G00FWQMDSZQA033KW94W

Installed the gauge and started investigating the noise I heard at the end of my last ride. I assume it was detonation but the mopeds loud and my helmet also muffles things further. So right off the bat I adjust the needle position one spot lower (clip down/needle up) in hopes to add more fuel at 3/8 to 3/4 throttle. That is where i heard the detonation roughly.

I adjusted the low speed needle until I made good power and had decent throttle response (2 1/4 turns out). Starting and idling the moped on the stand with no throttle input, after warming up the idle temp floated between 154°f to 162°f. To be double sure I didnt have overheating issues on a fresh topend I closed the slow speed needle 1/4 turn so 2 full turns out total. After letting the engine cool to ambient temp again I retest idle temp which is now peaking around 154°f. 

Decided after putting on 5 miles on my road and not hearing any detonation as far as I could tell decide to go on another 20 mile test drive. Entire first half of the ride is steep uphill, WOT the entire way. Temp peaked at 309° f on the first half of the ride. Once reaching my destination again I let the moped cool completely too ambient temp before riding back home. On the return trip (all most all downhill) temps averaged 287°f and peaked at 302°f. 

In my last post I said that after cutting both wires on the replacement cdi it ran properly with no rev limiter. After installing the tachometer and doing a couple WOT downhill pulls I have realized that the moped still has a rev limiter. It kicks in between 9500 9580rpm.  

So after all of this testing and the cylinder finally making it over 200 miles im still not happy with top speed on the large hills in my area. With just me on the bike I drop as low as 10 mph. So my next plan of attack is to go completely through the transmission and tuning it until I find a happy medium between top speed on flats and top speed on hills. 

www.scootertuning.ca/en/variators-torque-spring/7059-torque-spring-motoforce-racing-set-of-3.html?search_query=MF84.101&results=1

www.scootertuning.ca/en/clutchs-clutch-springs/8062-clutch-springs-polini-evolution-soft-20.html?search_query=245.013&results=1

www.scootertuning.ca/en/clutchs-clutch-springs/8063-clutch-springs-polini-evolution-medium-35.html?search_query=245.014&results=1

www.scootertuning.ca/en/clutchs-clutch-springs/8064-clutch-springs-polini-evolution-hard-50.html?search_query=245.015&results=1

www.scootertuning.ca/en/variators-roller-weight/7075-variomatic-weights-adjustment-set-polini.html?search_query=15x12&results=8#/choose-15x12mm_3_50g_4_00g_4_50g_5_00g

www.scootertuning.ca/en/intakes-reed-valves/4029-reed-valve-stage6-vforce3.html?search_query=S6-3219000&results=1

www.scootertuning.ca/en/suspensions-shock-absorber/12006-shock-absorber-malossi-rs1-280mm.html?search_query=4615434&results=1

Waiting for the parts to come in atm but once they do and I have had a chance to test out some spring and weight combos I'll report back with what I come up with.

[geoffh]

How's that run leader gauge working out,I,ve looked at those before but thought it to cheap to be OK,hope I,m wrong.

Geoff

Thanks for the rep!y 

[proy]

Jun 16, 2021 14:54:35 GMT -5 geoffh said:

How's that run leader gauge working out,I,ve looked at those before but thought it to cheap to be OK,hope I,m wrong.

Geoff

It seams to be running great. Temps seam very accurate and the tachometer seams to be on the dot. It comes with a access panel to change the battery on the back.

I have no idea how long it will last battery wise. I also don't know how much in trust it to be weather resistant. The battery panel has a o-ring seal but I don't know how well it would stand up to anyone planning on leaving the bike outside.

[proy]

Ok so I finally got the last of the transmission parts in today.

Polini 5500, 6000, 6500 clutch springs.

Polini 3.5g, 4g, 4.5g, 5g rollers.

Motoforce 1000, 1500, 2000 torque springs.

I sat down yesterday and started by tearing down the cvt completely and looking it over. Pretty sure I am the first person to actually take apart the cvt.

After pulling off the rear clutch and variator I noticed a washer placed between the drive boss and the front variator. I moved the washer to the outside of the variator. Still over the splines behind the kick start cup. I picked up about 2 mph on flats and 4 mph downhill with the 9500 rev limit.

Now that I know how I am putting the variator back together from now on I took apart the rear clutch and started messing with the clutch springs and torque spring combinations with the stock 7 gram rollers. I settled on the 2000 torque spring matched with the 6500 clutch springs.

Take off was noticably better and uphill top speed (steepest longest hill in my neighborhood) went from 8 mph to 17 mph. The transmission was obviously shifting way too early. Launching at 6800 rpm and being pulled down to between 4000 rpm to 4200 rpm almost immediately. I figured as much but wanted to change one thing at a time and in the rear pulley first instead of everything at once.

For chosing the roller weights I just started with the heaviest weight in the kit 5g. It ended up being exactly what I was looking for as far as I can tell. I didn't have time to really test drive it other then around the block today. With a little effort I'm able to get the front wheel all the way up from a dig if im all the way back on the seat. Hills are dramatically easier as well. Haven't had a chance to check speed with GPS yet.

So with the final setup I'm going to stick with for now is.

Polini 50% (6500) clutch springs
Motoforce 2000 torque spring
Polini 5g roller weights
Naraku 50cc topend
Stock head
Stock carb
Pod filter (plan on going back to factory airbox once I order that and a full set of jets)
Stage 6 V-force reeds
Stock variator
Stock clutch and torque driver.
Stock pipe

Currently launch rpm is 7300 and drops to 6800 within 30 ft and pulls smoothly up to rev limiter on flats. Will be doing top speed and acceleration tests tomorrow with gps and give some more numbers.

[proy]

Ok so minor update on the build. Pulled the engine out last week to check squish clearance. The factory head that I used had a very high wall to the combustion chamber when I originally assembled the naraku 50cc topend. I pulled the head off the engine and measured the depth of the wall of the combustion chamber wit a set of calipers. I don't have my notebook on hand but I know that it measured over 1.5mm from the bottom of the combustion chamber to the head gasket sealing surface. That coupled with the head gasket hight I was way out of spec in my squish.

After doing the math and having a friend with mill machine down the head so with a copper gasket I would end up in the ballpark of 1mm of squish. After assembly and checking the squish with ~1.5mm solder. I placed a length of solder trimmed to length tapped to the piston running diagonally from one head stud to another. I did this twice in both directions so I had four measurements to go off of. 

The actual squish worked out to be between 1.08 to 1.11 low to high between all four corners. I know that is still high but its a drastic improvement. I tried to do a squish test before any machining was done but the 1.5mm solder didn't even make contact. So I worked off of raw measurements of the head and gasket for machining. 

[Zino]

You will notice the Improvement It will be snappier.
I just normally try to get them to 1mm or less on the sport kits .

Most of the Sport kits just try to get under 1.5 mm .
All of us that tune these up chamfer the ports set the base gaskets for good port timing and then dial the squish tighter

[proy]

Credit for finding this out goes to df41590 but an alternative to the $100 eton cdi has been found so I planed on picking up one or two for my self as well.

www.scootertuning.ca/en/ignition-cdi/2060000-replacement-cdi-dc-kymco-super-9-lc.html?gclid=EAIaIQobChMIiNmVi-qp8gIVjb7ICh3toQpMEAAYASAAEgLkf_D_BwE

The cylinder head I had machined down keeps blowing head gaskets so im not sure what's going on. It always starts leaking in the same corner so something just isn't right.

www.scootertuning.ca/en/cylinders-replacement-parts/1049-remplacement-cylinder-head-50cc-minarelli-horizontal.html

I plan on replacing it with this head and looking around for a reputable machine shop with good reviews. I really don't want to waste another head.

Also on a side note about the hour/temp/rpm gage I posted about. The battery is already dead. In its defense ot was left uncovered in the weather and remained fully functional until the battery died. I plan on just replacing the battery and keeping spares on hand.

[beamerbro72]

Any updates on the project? Just getting into the beamers and I have 2. Just put a cheap 70cc kit on one and am having a heck of a time getting it to spark. I can pm you but I was curious if I could bug you for a couple pictures of your harness from the ignition switch on next time it's apart? I've searched everything and have had no luck! Thanks either way and I needed all the tuning info you have in this thread, it's gold to me!

[190mech]

Lots of Eton's use DC CDI which require a full charged battery to spark..There are quite a few Eton projects in the build section from some years back..A wiring diagram for your model will be needed as they had several different versions,,Good Luck!!

[proy]

Hey been dormant for too long. Finally got a second stage of parts ordered. Saddly shortly after installing the 50cc naraku kit I pinched the oil line from the pump and smeared piston all over the cylinder.

So first major change to note is I removed the drive gears from the oil pump assembly and switched to pre-mixing my oil.

After the catastrophic melting of the naraku kit I decided to do a full engine rebuild.

Parts I that are currently installed after rebuild:

Naraku high pressure crank with new bearing

www.scootertuning.ca/en/crankshafts-sport/2054-crankshaft-naraku-hpc-10mm-4250362423832.html?search_query=Naraku+crank&results=15

Polini 70cc sport BBK

www.scootertuning.ca/en/product-home-scootertuning/1015-cylinder-kit-polini-sport-70cc-8054705040108.html?search_query=70cc+polini&results=49

Polini crank seals

www.racing-planet.com/crankshaft-oil-seal-kit-polini-fkm-ptfe-for-minarelli-p-297016-1.html

Yasuni z pipe

www.scootertuning.ca/en/exhaust-systems-sport-50cc-70cc/3000011-exhaust-yasuni-z.html?search_query=Yasuni+z&results=58

Naraku 19mm PHBG

www.scootertuning.ca/en/carburettors-sport-midrace/5131-carburetor-naraku-19mm-phbg-4250362423559.html?search_query=Naraku+carburetor&results=13

After I had all the parts and tools (I bought a case splitter and crank puller set). Once I split, cleaned and reassembled with the fresh crank I installed only the 70cc polini sport kit at first along with the 19mm carb. I ran the engine like this all summer until I could afford the pipe.

At the end of summer I finally ordered the yasuni pipe. After installing it I was chasing a no start issue and found out my stage 6 v-force 3 reed block broke and was causing no start/ wouldn't idle issue.

Decided to replace the vforce 3 with a polini evolution reed block.

www.scootertuning.ca/en/intakes-reed-valves/4030-racing-reed-valve-polini-8054705068720.html?search_query=Polini+reed+&results=7

I am currently waiting on the reed block to come in along with some other goodies I'll post once they arrive.

Also experimenting with cdi's at the moment. I have 2 eton factory replacement DC cdi's both the 2 wire version. I also am currently planning on testing a kymco super 9 liquid cooled DC cdi to see if it will allow me to bypass the Rev limiter the 2 wire eton box's have built in.

www.scootertuning.ca/en/ignition-cdi/2060001-cdi-naraku-racing-dc-kymco-super-9-lc-4250362410788.html?search_query=Kymco+super+9+cdi&results=3

Once I have the reed block and I am ready to try first start with the pipe I will update once i know if the super 9 cdi is a good replacement for first generation PN2 beamers.

[proy]

Sept 13, 2022 23:29:11 GMT -5 beamerbro72 said:

Any updates on the project? Just getting into the beamers and I have 2. Just put a cheap 70cc kit on one and am having a heck of a time getting it to spark. I can pm you but I was curious if I could bug you for a couple pictures of your harness from the ignition switch on next time it's apart? I've searched everything and have had no luck! Thanks either way and I needed all the tuning info you have in this thread, it's gold to me!

What year is your beamer? Like 190mech said the e-ton beamers are all over the place with how they handle the ignition system.

Did you change the cdi box when you upgraded to the 70cc cylinder?

Have you done anything else to the moped outside of changing to 70cc?

Have you re jetted your carburator?

Are you still using the factory air box?

Have you confirmed that you have no spark by pulling the plug and turning the moped over with the plugh agiand the frame?

Do you have a battery you know for sure is good? The DC cdi systems don't like to start without a fully charged battery.

[aeroxbud]

That sounds like a good combination of parts. I liked my Polini sport. It will work well with the Yasuni Z.
Just remember the z has two restrictions.

[proy]

Feb 18, 2023 6:46:13 GMT -5 aeroxbud said:

That sounds like a good combination of parts. I liked my Polini sport. It will work well with the Yasuni Z.
Just remember the z has two restrictions.
 

Thanks for the tip. my pipe only came with one restrictor at the cylinder side flange which I had already removed by grinding out the welds. I looked into the silencer and there was no restrictor or baffle. So I don't think I have the second restrictor.

[proy]

so update. Just got the Polini reed cage in today and got it installed. jetted the 19mm carb to a #105 main jet currently running a pod filter with the stock intake tube that originally ran to the airbox that I retro-fitted a V-8 large valve cover breather filter that has a rubber grommet that surprisingly enough fits  snug and perfectly into the inner diameter of the stock intake tube. If any one is interested in seeing that contraption in photos ill post some photos. this is the way I have ben running the moped the entire time I have owned it. 

because of the clicking noise that I hear from the intake/reed valve I always catch my self thinking I am hearing detonation but its just intake noise. I have a factory airbox I plan on installing as soon as possible to see if that is where the noise is coming from. I would worry that its detonation but it never made it over 220 F on a several mile test ride. I varried the throttle and used all throttle positions but because of the wet and low temperatures it stayed extremely cool along with my suspicion of a #105 main is still to fat but start high and work down. 

On the news of the kymco super 9 liquid cooled DC CDI it does seam too cold start slightly harder but for it being in the upper 30 F outside and having to prime a dry crank case I did manage to get it running using the super 9 CDI. On my ride the pipe seams to rev out around 10.5K RPM and stayed stable around there. I sadly didn't get to run my GPS for a speed reading but its definitely faster then the stock pipe and the acceleration is phenomenal. 

so for anyone who ends up here needing a DC CDI for a first generation eton beamer (PN2) this is the CDI I am currently using:

www.scootertuning.ca/en/ignition-cdi/2060001-cdi-naraku-racing-dc-kymco-super-9-lc-4250362410788.html?search_query=kymco+super+9+cdi+&results=3

I will have to take photos and post links but I also replaced the run leader tach/temp gauge with two separate gages. Both gages are still run leader. The first gauge is a combo that can be switched between a temp gauge, battery voltage and a clock. The second gauge is a RPM gauge alone so that is always displayed. I have had no issues with the run leader gages so far as far as weather and accuracy but the batteries do end up needing to be changed every couple months but for the price point I cant argue if it saves me from a critical overheat or over rev. 

Tachometer:

www.amazon.com/Runleader-Tachometer-Maintenance-Backlights-Motorcycle/dp/B08FQZP7JW/ref=sr_1_1?crid=2A9NCRUL0CL20&keywords=runleader+digital+maintenance&qid=1677016813&s=electronics&sprefix=run+leader+digital+maintenance%2Celectronics%2C108&sr=1-1

Temp/voltage:

www.amazon.com/RunLeader-RL-TM005-Temperature-Thermometer-Snowmobile/dp/B01G6T1VF6/ref=sr_1_12?crid=195XSNMV726DK&keywords=runleader+digital+tach+voltage&qid=1677016916&s=electronics&sprefix=runleader+digital+tach+voltage%2Celectronics%2C167&sr=1-12-catcorr

If anyone plans on using the run leader gages then i would suggest mounting them in a way that you can get to the battery compartment on the back side of the gages. I initially used double sided tape on the first gauge I bought but the leftover adhesive and having to re-apply more tape every battery change was very tedious. one of the two came with Velcro that had a cut away for the battery door on one side of the Velcro and so far that is my preferred mounting method so far.

I also removed the electric start assembly and now rely on kickstart entirely. Instead of using shim washers (which will be ordered in the next round of parts) i cut the center of the one way assembly that has the splines cut into it and had a friend put it into a lathe and turn it down into a round even usable washer. Its not 100% perfectly centered/balanced but it allows me to assemble the engine without the mass of the starter assembly so I'm happy with it being a temp fix. Ill keep you posted if anything is going to cause issues i think that it is going to be this "hacked" spacer.

Well if you have made it this far and have been keeping up with the build thanks for the read and everyone's advice to me in my various threads so far.