1st Performance Upgrades

Seeing as I noticed before I'm going to have to strip the bike back to get at the carb for a few things & I'm going to be tinkering within that region anyway, I've decided to get the K&N 'style' induction air filter to fit on the carburetter now. I did some asking about & some say it's a 38mm diameter connection & others say a 42mm. I do know there is a bigger carb to buy to fit these engines as an upgrade in itself so not sure whether one measurement given is in regard to one of these? They're only a few £s, which again I was surprised about, so I bought one of each size to be sure. I'm hoping it's the bigger 42mm diameter, if so I have a use for the 38mm elsewhere.
You can have a shop about for them on Ebay, they come in various sizes & fit bikes & scooters from 50cc up to 250cc & are fairly universal & in either the washable K&N style or the foamy type if you prefer.

They are meant to boost horsepower, although not sure it will be a great improvement on it's own, together with other mods it will all add up but, again it's an improvement none the less. & a better improvement over the stock filter that would've needed replacing overtime. At this low price point I'm unsure why such air filters just don't get installed at the factory to start with to be honest? But then again there would be no extra income generated from replacement parts I guess?

Performance induction air filter:

For only £11.34 there was an race performance DC CDI unit available to use with the bike on Ebay also. So far this bikes been very cheap as a project, it's been great. Changing the unit is basically a 4 stroke's equivalent of how a 2 stroke is derestricted to allow for a greater power / speeds. The unit controls & alters the power curve of the engine & removes the RPM rev limit set by the original CDI. All in all it's a better quality unit in a nice aluminium housing over the standard plastic cheap looking one, if nothing else & people have noticed how much smoother the curve & ride itself is over standard.

You need to see whether your particular bike fires with an AC or DC system before purchasing a performance CDI. In this case I've been assured it's a DC system (I guess the same for the SKYJETS etc also?), although there are ways to tell by counting the number of wires for instance. However, I haven't had the bike fully stripped back to see that for myself, so I'll just go off of the information & hope it's right, I can always pick up an AC unit if not. Just in case the plastic connectors themselves don't match up I ordered some 15 AMP terminal block connectors for a £1.00 while I was at it. You could go for bullet connectors or something similar but would have to solder them onto the wire ends. Of course you could directly solder the wires together but future swapping would be hampered by having to mess about to unsolder them to replace a future unit. That would be up to you. The CDI unit appears to be located underneath the fuel tank.

There are many units available but the one in question I picked up was a Casoli DC unit that works with Honda based 156/157fmi engines like this one & the GY6 Honda based scooter engines in DC. You should be able to pick them up on Ebay or somewhere like Ali Express for £10 - £15:

http://www.aliexpress.com/item/Racing-motor-Alloy-CDI-for-157FMI-CG125-150cc-200cc-250cc-4-stroke-Engine/1395408488.html

*If you see something for either 157fmi or 156fmi it's the same engine. The exact measurement is 156.5 and some manufacturers round it up one way or the other.

The unit is supposed to offer a boost of about 8 - 10 % in BHP. Likely around 2 BHP at the most. Doesn't seem a lot on paper but seeing as the 125cc engines put out about 11.4 BHP in total it could be a nice little boost. & still keeps it under the legal limit.

11.4 \ 100 = 0.14 (that's 1 % of 11.4 BHP)

0.14 x 8 = 0.912 BHP

0.14 x 10 = 1.4 BHP

(8- 10% improvement).

Casoli performance CDI unit:

Original CDI unit:

I think it's best to wait to do all this at once seeing as I would need to keep on removing parts of the bike to the same extent over & over again for each part & carb adjustment and I offer this advise to anyone else. I know putting bigger jets in the carbs can be a good upgrade but at this time I won't mess around too much with the fuel / air mixture. I could find myself in engine running trouble jumping in with that alongside everything else. If I need to revisit that later on I will do.


*EDIT. Read ahead, I had trouble getting a performance CDI unit to function with this engine. Don't order one unless it's at some point in the future and you know for sure it's a working model that's compatible with the engine (and if you do manage to find one drop me a comment).

Close Quarters

Just a couple minor upgrades again that won't cost no more than a couple of £s. First of all I wanted to change the spark plug cap on the XTRS' HT lead. It has one of those Chinese designed 'all metal' jobs on it & although it seems to work fine, I remember stories of people having intermittent problems in the wet weather with these on other types of Chinese bikes (like the cruisers etc) in the past, with regard to magazine articles I've read & motorcycle forums I've frequented. And all in all I'm just not in the right frame of mind about something all metal that is designed to be part of the electrical ignition system! It's something I would recommend doing personally.

The standard cap:

I decided to change the cap for a good quality NGK one. Changing the caps themselves is not an overly difficult task. There is a self tapping style screw inside the cap attached to the HT lead end which screws into the lead & the copper wire core inside, making contact. Removing it is just a case of unscrewing it in an anti-clockwise manner while holding the lead still with your other hand. Attaching the new one is just the opposite & just requires screwing onto the lead. Remember to put the rubber seals which came with the new cap onto the lead before you screw the new one on, they're there to stop moisture from getting inside & you might need a little force to do so!

To get to the spark plug area itself you first need to remove the upper right side fairing. just undo a few strategically placed screws, not forgetting the ones placed at the front inside near the front wheel.
While I was there I was also going to replace & upgrade the spark plug to an high performance NGK Iridium plug: http://www.ngksparkplugs.com/products/spark_plugs/iridiumix.asp?mode=nml
The plug itself is supposed to give both a boost in performance & fuel economy. So I swapped them out while I was there.
It's very close quarters itself working within the area as part of the chassis comes right across close & I thought I was going to have trouble removing the original plug, as none of my spark plug spanners would fit in there! I also didn't have the little toolkit included under the rear seat, which sometimes includes a crude socket to remove the plug with a hole in for a screwdriver to lever it round. I started to become concerned. & rummaged in one of my old socket drawers & found a spark plug socket that fitted both my spark plug & socket set, even if it didn't fit the socket set or I wasn't able to get it in (that's what they all say!), it had the nut molded on the top to be used with a spanner. I was lucky, I didn't need to make a trip down to Halfords to buy one after all.

Close quarters:

With about 2cm turns at a time I was able to remove the original 'Torch' Spark plug. I'll keep this plug around as a spare should I need it, It seems to work fine, I was just always going to change the plug for a new decent one if I was in that area.

Looking at & inspecting the tip of the old plug itself, it seems to be running a bit rich & needs to be leaned out a bit at the carburettor (air / fuel mixture). I need to up the idle speed screw at the carb a touch anyway, as it seems to be idling at bit low & I've noticed I'll need to take the bike apart some in order to get at it properly. So I'll leave it all to be done at the same time. It's also probably not the best time of year to be stripping the bike down either now, cold & wet outside or stuck in a freezing cold garage!

Running a bit rich:

NGK Iridium:

When screwing a new plug in always make sure to be patient & do it by hand first to make sure you don't cross & damage the threads on the engine's cylinder head. You can repair damaged threads with a Helicoil kit but, it's a road you really don't want to go down. Finish by tightening with tooling until secured. & the new cap should just push down with a 'clip' on the spark plug with some pressure.
I cable tied the loose HT lead to the chassis to make sure it doesn't flap around, loosening the cap off the sparkplug over time. It would be a right pain in the arse to be driving along and have the thing shutoff because it knocked the cap off half way down the highway!:

Aesthetics

Ok, how the bike looks. The XTRS looks ok, nothing too wrong with the decal scheme on this black version of the bike (there is a red & a white version available). However they do look a bit boyish & 18 I'm definitely not no longer & it wouldn't be much of an 'project' without changing the looks or cosmetics of the bike to how I want in some way either, would it? I must point out if you don't want to void a warranty then don't do it!

First off I started by completely de-badging / decaling the bike:

 It doesn't look too bad like this to be honest but I have further plans for the bike yet, involving some vinyl wrap. All that was left was to remove some of the sticky gunk left underneath with some T-Cut & an old rag.


You can remove the decals easily with a heat gun set to a low setting, so you don't melt the plastic fairing. Best to start lowest, then notch it up ever so slightly. If you don't have one you could try an hairdryer. And then just peel them off.

If you have trouble removing some of the gunk you can use the heat-gun again & an old plastic card to scrape the glue off. It has to be plastic so as it's not too hard to scratch the fairing underneath:

All that's left then is to get some T-CUT & an old rag and completely remove any of the gunk & residue left behind with some elbow grease (hard work not actual grease!):

It does seem to leave a slight outline where the decal has been, which indicates the paint work as a whole has some sort of plastic coating maybe? But it's not a big deal:

Feels as if the bike has a slightly mature look to it without the decals.

I would also like to point out a fact I forgot to mention earlier which is the fact that the bikes are based on a clone of a previous model Honda CBR 125 R aesthetically. & again many of the Honda parts fit the bike:

The Lexmoto XTRS

Waiting around for an V-Twin Honda Varadero for ages I decided to take a plunge for the Lexmoto XTRS 125cc KS125-24 while I wait. The Veraderro being an big V-Twin no longer in production & in demand can hold it's price high. The average life span for any 125cc no matter who the manufacturer is, is about 4 -5 years, mainly in terms of the engine life, rebuilds etc (even if you know of ones lasting much longer) & paying a high amount for a nail with the  Varadero like any 125 of a certain age is an obvious possibility. That's something I have no intention of doing, so I'll wait for a decent one.

I managed to get an 5 month old machine, virtually brand new (XTRS), which means I don't have to run it's engine in as it virtually has been. The thought of having to run the thing at 30 - 50 MPH everywhere while it was running in would've been a killjoy to any of the project mods.  It is a chinese manufactured bike & although in the past people have had trouble with such bikes, they seem to be getting their act together in much the same way the Japanese did. Of course there's better manufacturers than others in this arena too & Lexmoto appears to be one of them alongside the likes of Sinnis etc.

The XTRS itself is an update over the previous XTR model, although the two look near identical. I think mainly it's update is down to the engine, an OHC (over head cam) version of an Honda based 156 / 157fmi CG engine (a licensed adapted clone) laballed an 156 fmi 2. The previous model used a standard OHV (over head valve) version. The OHC allows for slightly more power / speed.
The engine is a 4 stroke, so 'reliability' over speed. It's rated for around 70 MPH, which to be fair is the UK speed limit any way. Of course with the project the aim will be to try & get more power & speed than that, if possible (even if I do have to carry out the speed tests on private land).

I've been assured any 156/157fmi engine can go in or be swapped out for another chassis designed to take one as they have standardized fittings. There are many different chinese licensed clones around as well as the genuine Honda ones, so it's always good to know, should I damage the engine messing around. Although there's also a comprehensive list of individual engine components available too.

So it won't be touching speeds near 100 MPH + off the bat like it's 125cc 2 stroke counterparts but, it won't be going BANG! Like them either. Trust me, I know from experience just how much of a pain & how temperamental 2 strokes can be, even if they are quicker. A bike that works is always better than one that finds itself in pieces on the garage floor every couple of months.
People talk about chinese motorcycles but I've seen certain Italian bikes engines blow & heard many more such stories from other owners elsewhere in regard to them. I've even seen the after math of two friend's Japanese blown engines too. I'm not too bothered about the bike being chinese & it's all part of the project experience. Look after your bike & you should be fine full stop. This engine should be bulletproof, unless 'I' do something to hamper it.

The XTRS has it's fair share of chinese dopplegangers, under other names knocking around also. For a start it's sold under the brand name Kaisar elsewhere & is also imported as such. SKYJET, Superbyke, Yuan, XJGAO, & Mototek are just other brand names for the identical bike. Although which ever engine version they use is for closer inspection, all the other parts are interchangeable which means getting spares & mod parts is even all the more easier online. & people that own versions of those bikes can also make use of this blog.

A SkyJet:

An quick early mod was to exchange the bulky original bulbed indicators either side of the front to small Lextek l.e.d versions, as one needed replacing anyway. It involved the removing of the side panels, securing the indicator to the fairing with the provided nut & connecting the two wires where the previous flasher was connected. No new flasher unit was needed to make them flash & the indicators work just fine as they are. I was going to replace the back ones also but wondered if they would be a bit short visibility wise, especially in the daylight? So I left the back for now. There was a small hole left where the old indicators were connected but isn't a big deal, besides I plan on vinyl wrapping the fairings later anyway & they won't be seen at all then. I also added an new set of wing mirrors, they were cheaper to get the Skyjet ones so I did. It was pointless an spending unneeded amount especially on something like that, which was the beauty of my point about parts earlier.