Project XL185/CG250 swap

[XLsior]

Sunday back road blurt to the cheapest fuel station around and back to see how the Aussie Muffler mods worked out.

I feel like it has opened up flow with the new DIY baffle and not audibly better or worse than it was stock.

Seems decel popping has also tempered down to the odd 1 pop rather than a sequence of 3-5

Throttle response seems sharp...Its been very windy so hard to say how flat top end 5th went....but I think there's an additional 100-300rpm improvement across all gears.

I checked the spark plug and its not bad but I think it's looking slightly cappuccino/flat white and less coffee grounds/nutmeg.

So I will bump up my main jet.

More than happy enough with the current performance of the exhaust.

Side note my kickstand foot/pad knocked off when I failed to kick the leg back pulling away "doh". I have ordered a replacement with a top retention plate this time.

Also managed to zip tie 3 tire levers to the frame under the fuel tank along with a front spare standard inner tube in an old sock (insert tube sock joke) in the under cavity of the tank. So my emergency flat situation is looking solved.

[XLsior]

I have proved that my current original cylinder Pool Noodle Hone worked and is currently running in the bike fine without leaks...

https://www.chinariders.net/showthre...ht=pool+noodle

I purchased my 70mm big bore kit prior to 73mm skirts being listed with the intention of just getting the 76mm machined down...

Well I made an inquiry and a local machine shop and just getting the surface decked was an $80 dollarydoo prospect...let alone getting the skirt turned down...

Basically getting the work done would cost more than just buying a new '73mm' kit from aliexpress.

With that prospect in mind...

I am opting for DIY experimental reasons to try and shade tree the skirt down to 73mm with a finger belt sander attachment for an angle grinder (which I have ordered online $30)

While that's on its way I am decking the head mating surface with 40/80/240/400 grit sand paper...Some of which I kept some floor sanding belts finer grades are wet/dry for finishing.


I am using the chamfered edges on the location dowel recess holes as a depth gauge as they appear to be about 1-2mm and are in 3 locations across the surface for level plane confirmation.

once all 3 chamfers are sanded down then no more major material is to be removed and surface scratches are finished down to a smooth clean surface.

Of course I am not recommending this process to anyone...

But lets be honest here its a single cylinder with push rods...not a space shuttle

[XLsior]

some slight outer edge rolling from the sand paper curling up...

Could be avoided by using spray adhesive on the back of the sanding paper and sticking it the true flat surface...in my case 10mm float glass

but the main gasket mating surface appears fine and flat.

Not sure how well the included metal head gasket will work, a composite gasket would be far more forgiving...

I'll use some gasket dressing if/when installing it.

But it is what it is...

[XLsior]

Installed the new CB500X kickstand foot pad, used some liquid nails to make it a more permanent install....

Went for a 3hr back road explore figure 8 local surrounds.

Mostly paved but some gravel.

had a slow speed front wheel wash out on a down hill right turn gravel intersection.

Pannier bag shredded. Front fender paint chipped and rashed bark buster.

I would say the bark buster saved the day and the tank from damage...

The fork brace probably paid for itself too...

Paint was already bubbling on the fender so no loss really...Thinking of just painting cheap black 2x or even spray bedliner....

the pannier luggage situation will have to change. Looked into Ammo boxes (heavy) and Pelican Cases (expensive) But think I will attempt a DIY plastic jerry can mod.

I was carrying some emergency fuel in an empty 500ml 3d resin aluminium bottle, which didn't rupture flying out of the ripped bag but took a beating. Sort of worked but 1litre would be a better amount.

[XLsior]

So yeah 3 hours on the saddle definitely made aware of some comfort issues.

There seemed to be a ridge/slope that kept pushing the seating posting forwards and made any attempt to sit back for awhile uncomfortable which forced to keep the knee bend almost locked in position

This would also put more pressure on the groin region.

Anyway the situation needed to be amended.

Took the cover back far enough and peeled away my memory gel foam layer to the factory foam.

Using a fine serrated bread knife and my fish filleting skills cut back about 20mm 5/8" thick layer off the rear seat. Then spray adhesive and relay the memory foam...

Just letting some glue help hold the back of cover better clamped down with pegs for now before re install...

But i can already tell the seating angle is far more forgiving now.

[XLsior]

I received the 2/1 speed metering gear set from aliexpress...

I believe it would have worked...

However the issue is, for whatever reason Honda felt a super tight interference fit bearing holding the transfer shaft/worm gear appears to be a non serviceable part...

I tried heat and chill spray but no amount of tapping or pulling made it budge.

Gave it a decent effort...

So rather than push my luck I have decided to forgo the factory speed metering drive + dash adapter.

and fit a permanent magnet to the rear wheel hub and the pickup unit to the rear drum hub for a 1 wheel turn per signal output.

[XLsior]

Got the finger belt sander adapter for the angle grinder.

ordered a few 40grit belts as the belts that were included were not coarse enough to remove material.

It has taken many passes using a marker pen to help maintain some consistency with each pass..

Gone through a few recharges on the 4ah battery packs so it is slow going.

But it's getting there.

Not quite 73mm yet...

but under 74mm.

[JerryHawk250]

I like the way you approach your project. You use what you got and make it work. I do a lot of my projects that way. It's more enjoyable for me.

[XLsior]

I don't mind if the tools required can be used elsewhere and are not just 1 off. So getting the finger sander wasn't a waste of money.

A 73mm cylinder out of the box would be the better choice, but they weren't a listed item at the time I purchased my 70mm piston kit.

Getting it machined by the professionals would have cost more then just getting another correct sized cylinder from Aliexpress...

So I didn't have much to lose other than time investment which I am fortunate to have ample.

I grew up fairly isolated in rural Australia so being resourceful and solving problems with what is at hand developed with the environment.

There's definitely more to do with a old bike resto-modification than just buying new... Pros and Cons.

I have more appreciation for the time investment of things, than the size of a persons bank account...Not to say I don't appreciate new bikes or those who work hard to afford them...

Just doesn't float my boat like DIY custom does.

[XLsior]

Made the executive decision to install the magnet and sensor unit that came with the Acewell 3701 digital dash as standard equipment.

The front wheel adapter was purchased separately.

drilled and tapped for M6 to install the magnet to the rear wheel hub.

Drilled and tapped into the rear drum brake backing plate for the sensor unit.

Seemed to be the most protected location.

tested the pickup before drilling and tapping holes.

[XLsior]

The Finger sander got down around 73mm...

Time to see if it will fit.

Had to tip the engine forward on the bottom rear mount to remove the head and cylinder...Thankfully it was not a total engine remove from frame job.

The pool noodle honed original jug got me over the finish line with getting the bike road legal and registered, But there was a fair bit of piston slop and I have noticed the bike was consuming a bit of oil...

So off it went, I measured the case opening and it was about 74.4mm, So 73mm might be overkill.

Test fit the finger sanded big bore and it went in without much fuss...

the case opening already had a chamfered lip and with wider opening + the gasket thickness I don't think it got hung up with any possible tapering.

So took it out and installed the cam rollers and checked ring gap then installed the piston.

used gasket dressing on the case paper gasket and sprayed the steel head gasket with some high temp paint that is supposed to have ceramic stuff... Just to fill in any possible flaws and scratches in the mating surfaces.

Then torqued it all to 25ft lb/34nm.

[XLsior]

Ok user error.

I installed the oil feed o'ring under the head gasket for some reason and had a compression leak...

So had to take off the head again...

Then inspecting the head surface it was apparent the o'ring did not have a locating recess. Which i might have sanded back or just wasn't Zongshen fitment as the composite head gasket they use had room for the O'ring to seat.

Well I got the dremel and made a chamfer enough for a new oring to squeez home and proceeded to torque the head down again starting with the oil feed head bolt.

Hopefully the metal head gasket is still fine...

But some other discoveries were made too...

[XLsior]

Prior to fixing the compression leak....

I found that installing the push rods and rocker arms the adjustment had to be backed right off.

My impression is : the contributing factors of a 'decked' head and jug 1-3mm, a thinner head gasket and the cam rollers...Put the push rod throw over adjustment specification.

I got around this by installing the 3 washers under instead of on top to act as a spacer...which would have worked I think. (I am not condoning it but it worked as a quick fix) and put valve lash back into tolerance. Did not foul on the rocker cover...

And running over on the starter motor nothing seemed to interfering and turning over nicely...

However that's when I found the compression leak and had to take it all apart again.

In doing so I also found 1 push rod was slightly bent (would not roll on a flat surface smoothly)

I also decided to shave 1.5mm from the 3 locating dowels to remove them from the potential compression loss cause...

I looked on Aliexpress for new Push rods Standard CG250 is 153mm...But also listed were CG198 pushrods 148.5mm, So I have ordered those to in theory compensate for out of valve adjustment issue.

As of now the bike is parked waiting for new push rods.

Thankfully the weather is terrible for riding.

[XLsior]

Got some ebay knock off Rox bar risers that arrived today.

I didn't quite feel right on the pegs with my hand position much lower than I would like. Maybe this is a newbie error...but it felt low and I am a novice rider, so I'll attempt to improve/reassure my confidence if anything.

While seated at full lock it almost felt like I was trying to punch myself in hips.

However I didn't want to use block risers and close the user space/rider gap ergonomics...

Tilting the current bars back would impact wrist angle...

So I needed risers that would pivot back as well as raise height.

I do like the adjustability, perhaps at the expense of strength/rigidity ...but i discovered my handle bars are bent after the gravel road bint.

So Ive ordered new ebay knock off protaper tapered 28/22 fat bars.

Gives the bike a bit more of a staunch stance....like 80s David Byrne shoulder pads.

Just adding farkles now while waiting for the push rods to arrive...

[XLsior]

I managed to find a replacement reproduction steering stem lock on ebay international...

(I did not have a key for the original and a locksmith re-cut would cost to much)

the seller has since removed shipping to Australia...I'll chalk that up to my order.

Getting a Genuine Honda replacement was out of the question.

However looking at other alternative bike lock methods the price of replacing the stem lock was justifiable...

More of a deterrent of course...I've seen bike thieves in India/SE Asia just reef and overwhelm the stem locks in a matter of seconds...

But where I live...I just need enough of a deterrent while I'm in the shop for milk and bread, or casting a fishing rod at the beach.

Quality is excellent, think it was made in Portugal and sold via Germany.