About to upgrade the cg 229 asking for input

[paulsstag]

I am about to (mid Nov) try to get a little more out of my Recon 250 engine as others have done but wanted to ask whether certain things really need to be done?

Just like others i am aware of the limitation of the engine but for the most part i am looking at more low to med grunt to be able to accelerate quicker and maintain speed on hills , ideally would like to maintain 65mph in high elevation (6000ft) . Top speed is not my goal but 70 mph would be nice if needed.

So i have a mild cam and roller followers on order (i think its the same one others have used?)

4 degree advance key way.

I plan on a 1 mm shave of the head plus port and polish.

Just finished reading the post and link one legged put in about a sleeve and piston kit to go to a 69 or 70 mm piston, which i'm seriously considering as my engine is about to be worked on any way (cost about $100 with shipping)

Question : do i need an upgraded CDI box if so does anyone recommend one ?

Is my pz30 carb big enough/ flow enough or should i step up to a different one ?

Is the stock air box and filter able to flow enough air or is a pod filter set up the way to go?

Currant gearing is 17/43 and i have the ebay cfr 230 exhaust on the bike already.

I would appreciate your thoughts and advice or even suggestions .

Oh what about an oil cooler? i am never in traffic but would like to ride further 50 miles on open road to explore more trails?

[paulsstag]

not exactly the response i was expecting

I will try my best to get some real time results of before and after the mods. to share with others when i'm done.

[JerryHawk250]

The only thing i see on that list that i would change is upgrade to a smooth bore PE30 or PKW30 carb with a pod filter. The PE30 will be the better for easy access to idle speed screw.

[China Rider 27]

Originally Posted by paulsstag

not exactly the response i was expecting

I will try my best to get some real time results of before and after the mods. to share with others when i'm done.

Looks like you have a plan already so I could not add a lot to it other than to think you may need a carburetor upgrade in the end.

I think you have a great idea to get some "real time" results. I suggest starting a thread to detail your progress with good pictures. I suggest some way of measuring progress starting with where it is at now. Most people think of speed but maybe think about any other ways of measurement. Gonna be a lot of fun I say!

[JerryHawk250]

I wouldn't worry about the CDI. The 4 degree timing key will be a big improvement. I've played around with the so called performance CDI's and didn't feel any difference. Eventually I'll install the 4 degree key on my Hawk. It really woke up my X22R.

[franque]

Just make sure you've got a machinist who will do the work on the cases for the big bore. I understand the case mouth needs to be bored out a little bit. It might interfere with the oil passages (the do in the same engine family with some of the smaller motors, the '250' is a small redesign in some ways), so that might need to be welded to make the oil passages work as intended. Keep us posted, I'm fairly certain no one has done the bb kit on here.

[paulsstag]

Originally Posted by franque

Just make sure you've got a machinist who will do the work on the cases for the big bore. I understand the case mouth needs to be bored out a little bit. It might interfere with the oil passages (the do in the same engine family with some of the smaller motors, the '250' is a small redesign in some ways), so that might need to be welded to make the oil passages work as intended. Keep us posted, I'm fairly certain no one has done the bb kit on here.

I was not aware that i might get into the oil passages ? That is a little concerning. Good to know these things ahead of time and make appropriate plans.

Thanks Jerry for the insight on the carbs. i will get one of those ordered with a pod filter to match as well as jet assortments to match my elevation (6000ft).

Also good to know about the ignition box (CDI).

Many moons ago i bought a brand new Nissan 1400 pickup , in the owners book was a set of smaller main jets and a set of bigger air bleed jets for use at higher elevations (6000ft), the instructions called for the jets to be installed , the timing to be advanced 4 degrees and a recommended set of spark plugs that if i remember were 1 heat range colder? This was from the factory .

Thanks for the input
Paul

[JerryHawk250]

If you plan on riding trails at low speeds I would consider an oil cooler. These engines will stay cool as long as you are riding up top speed. Slow trail riding will tend to heat the engine up. I have a head temperature gauge on my hawk and my hawk runs the hottest when I'm out on the trails tractoring along. I've thought about installing a couple of small fans on the oil coolers I can switch on when needed.

[grumpyunk]

As I understand, and was stated in the post about the aliexpress larger bore, the crankshaft and connecting rod would need to be replaced.
Did you go with the larger bore? How did it work out? Did you install the roller followers? IOW, any progress to report?
tom

[paulsstag]

Originally Posted by grumpyunk

As I understand, and was stated in the post about the aliexpress larger bore, the crankshaft and connecting rod would need to be replaced.
Did you go with the larger bore? How did it work out? Did you install the roller followers? IOW, any progress to report?
tom

Update on the progress so far.

I decided to not do the big bore kit at this time as it was pointed out i may get into the oil passages plus i would have to do a case split , take out everything then bolt up the cases to send to the machine shop.

I also did the math on what a 70mm piston would be in terms of cc ? the figure i came up with was right at 250cc ?? so i assume the 271cc that one legged had mentioned must have an increase in stroke to get it?

It would be a fun project to do the crank kit and sleeve/piston kit but i would prefer to work from another engine (maybe one that is in need of a rebuild anyway) so my bike would not be down.

When i pulled the top of my engine apart i noticed the piston is still 'down the hole' about 3mm when at TDC so i believe there is room for at least a 2.5mm stroke increase without having a taller engine.

I did put in the bigger cam and roller followers which was just bolt in stuff.

I pulled the flywheel and added the 4 degree timing key.

I finished porting/polishing the head this morning so should get that back on tomorrow .

I plan on just putting the stock intake and carb /airbox on the engine to get it started (known entity) and after its up and running (on the bench) i will mount the new intake, carb and pod filter to get the jetting dialed in.

Paul

[JerryHawk250]

Paul, I think you will be more than happy with the power gain with just those mods.

[Deckard_Cain]

Originally Posted by JerryHawk250

Paul, I think you will be more than happy with the power gain with just those mods.

Absolutely agree here.

With a good carb/pod filter, full exhaust, cam and porting on the head, timing advance key the 229 has really good power for its size and is still reliable and durable.