Seized my Blur's engine!

[babblefish]

Still waiting for parts to arrive:

I've got a 61mm cylinder kit, A12 cam, 30mm OKO CVK carb, 30mm intake manifold, jets, Dr. Pulley sliders and a new belt coming from Taiwan (seller Carlos, AKA "autotech355" on EBay). BTW: Carlos is a great guy to buy from because he's really helpful with picking the right parts.

I've also got a performance clutch, 30mm intake manifold and cooling fan coming from MonsterGY6 (www.monstergy6.com).

Yeah, I know, what's with the two intake manifolds. Well, I had already ordered the intake from MonsterGY6 before ordering the carb from Carlos at autotech355 and didn't realize that he (Carlos) included an intake with the carb. So, if anyone needs an intake for a 30mm carb, PM me.

The parts from MonsterGY6 had to be resent when UPS forgot what customer service is all about and sent my package back to the seller, hence the long delay. I had it resent via USPS instead because they at least give me the option of picking it up at a local post office. Yeah, I had to pay freight a second time...

[gearhead]

did you also buy the gasket set that fits the blur from carlos?

[babblefish]

did you also buy the gasket set that fits the blur from carlos?

No. I bought a generic set from www.partsforscooters.com then when I discovered the transmission (variator) cover gasket wouldn't work, I ordered it and the center crankcase (where the crankshaft lives) gasket from www.scooterloungeonline.com. The center crankcase gasket from the kit would have worked, but I bought an extra just in case I had to split the cases again.

[babblefish]

Just catching up on this. Sounds like you are having fun.

My blown Blur 150 is still sitting in my computer room. I get to look at it every day!

Wow! You still have that thing around your neck?
I heard from someone in Taiwan that PGO had problems related to the connecting rod that caused a lot of engine failures. I'll bet the same thing that happened to mine happened to yours except with a lot more consequence.

Well, you can always convert yours into a floor lamp!

[KS Power Nick]

You are going to want to do some work to those intake manifolds. They flow like crap. After some port work that are not too bad, but out of the box they suck.

[babblefish]

You are going to want to do some work to those intake manifolds. They flow like crap. After some port work that are not too bad, but out of the box they suck.

Really? What is so bad about them? They're suppose to be opened up for a 30mm carb, but I'll certainly check them out once they're in my hands. Thanks for the heads-up.

[KS Power Nick]

You are going to want to do some work to those intake manifolds. They flow like crap. After some port work that are not too bad, but out of the box they suck.

Really? What is so bad about them? They're suppose to be opened up for a 30mm carb, but I'll certainly check them out once they're in my hands. Thanks for the heads-up.

You have to use one for a 30mm carb to work. The internal shape of those intake is horrible for flow. They can be made to flow ok with some port work.

Also one thing to note. Those 30mm OKO carbs are meant for 2-stroke engines. The needle in them is not perfect for a 4-stroke. The part throttle will be off.

This is why I ONLY use Mikuni Carbs. They are not that much more and there are tons of parts that are EASY to get to tune the carbs in the way they are meant to be.

[babblefish]

If the OKO carbs are meant for 2-strokes, then why are they stock in the 4-stroke Buddys and Blur? Just curious.

[KS Power Nick]

If the OKO carbs are meant for 2-strokes, then why are they stock in the 4-stroke Buddys and Blur? Just curious.

OH HANG which carb did you end up getting exactly? If you got the 30mm CVK carb you will be fine!! If you got the slide carb it will be the pain to tune in.

So which carb did you get. ATUOTECH555 sells both.

[babblefish]

This is the one:

http://cgi.ebay.com/ebaymotors/Power-IN ... ccessories

Two reasons I choose this carb:

1) Direct bolt-in with no mods other than jetting.
2) Has the automatic choke.

[gearhead]

ohh nice carb!

are you going to install something to relieve pressure in the crankcase?

[babblefish]

ohh nice carb!

are you going to install something to relieve pressure in the crankcase?

Yes, but I'll probably end up making something rather than buying one of those high priced canisters.

[babblefish]

Oh boy! More pics!

Here's a pic of my new NCY clutch (left) next to the stock clutch. Notice the greatly increased friction pad size. Also, the changable springs and weights to allow for fine tuning of the clutch action. I'm also changing the big torque spring (the one that pushes against the rear CVT plate) from a blue (1000 rpm) to a yellow (1500 rpm).


The modified kickstarter coupler and Dr. Pulley variator plate. I drilled four 1/8" holes into the coupler sized so that the hardened dowel pins are a press fit into it. But before inserting the pins, I used the coupler as a jig to drill the four holes into the variator plate guarenteeing alignment of the holes. In retrospect, I could have probably gotten away with using just two dowel pins since each pin is rated for 3,200 lbs shear strength for a combined total of 12,800 lbs. Unless I gain some serious weight, I'm pretty sure I won't come anywhere close to breaking them off. Anyway, now my scooter will be wearing suspenders with it's belt. AKA, electric start and kick start. BTW: if anyone needs 1/8" x 3/8" dowel pins, let me know because I had to buy a box of 100 from McMaster Carr. I have a few extras...


This shows the difference in spline/thread lengths between the stock crankshaft (upper) and the +4.2mm stroker crankshaft (lower). The shorter splines are just long enough to engage the variator plate, but not the kickstarter coupler.


I've started doing the port work on the Ruima head and will do some work on the intake manifold.
Originally, I was going to just reuse the stock exhaust system, but after looking at the size of the new head's exhaust port, it's obvious that the I.D. of the stock exhaust manifold is going to be too small for good flow. So, I'm shopping for a new exhaust system. Something in carbon fiber and stainless I'm thinking. Anyone have any experience/opinions about this one from MonsterGY6?


This is starting to become an awfully big can of worms....

[babblefish]

If the OKO carbs are meant for 2-strokes, then why are they stock in the 4-stroke Buddys and Blur? Just curious.

OH HANG which carb did you end up getting exactly? If you got the 30mm CVK carb you will be fine!! If you got the slide carb it will be the pain to tune in.

So which carb did you get. ATUOTECH555 sells both.

OK, after doing some research, I found three different types of carburators using the term "OKO". Now I know what you were getting at. The other carb that I had been considering was the Keihin OKO PE 28 which I've been told gives better throttle response and is more suited for high performance work. The only thing that held me back was the manual choke. That's ok though since the CVK type carb is much easier to intergrate into my scooter.

[babblefish]

You know...the best thing about this rebuild is the excuse to buy new tools...

[Lostmycage]

You know...the best thing about this rebuild is the excuse to buy new tools...

Hell yeah.

[KS Power Nick]

When looking for Exhaust systems for the blur. Remember that they are not the same mounting as the standard GY6. So you may need to get a different head pipe.

[babblefish]

When looking for Exhaust systems for the blur. Remember that they are not the same mounting as the standard GY6. So you may need to get a different head pipe.

Are you referring to the way the stock head pipe wraps over the fan housing vs under as on other scooters? Or is it the way it bolts to the head? The way the muffler mounts are attached?

[bigbropgo]

When looking for Exhaust systems for the blur. Remember that they are not the same mounting as the standard GY6. So you may need to get a different head pipe.

Are you referring to the way the stock head pipe wraps over the fan housing vs under as on other scooters? Or is it the way it bolts to the head? The way the muffler mounts are attached?

Probably all of the above. That's pgo for ya.

This has been cool to follow. Thank for sharing your rebuild. Hope it all comes together for you.

[babblefish]

Just for general information, here is a picture and specs comparing the stock Keihin main jet and the OKO (Keihin?) CVK main jet. The smaller Keihin jet is very hard to find. Most places stock just the larger size.

[gearhead]

where can you find the torque values for the crankcase and head?

[ichliebe]

yeah ,who can tell us?

[KS Power Nick]

yeah ,who can tell us?

Case bolts I torque to 5-7 ft lbs

Cylinder studs 12-15 ft lbs.

[gearhead]

yeah ,who can tell us?

Case bolts I torque to 5-7 ft lbs

Cylinder studs 12-15 ft lbs.

thanks for the info!



now what's going on with this build?!? crickets*

[babblefish]

OK folks, I'm back!

Haven't had time to deal with the Blur for awhile, but with summer coming, I've given it more priority.

The only thing I've done recently is to buy the correct tool/jig to bore out the crankcase for the bigger cylinder.



I'll be posting pictures of how it's mounted and used. I can tell you one thing for sure, it sure is a PAIN to remove the four cylinder studs from the crankcase. Double nutting the stud and using a wrench didn't work for me. And forget about using ViseGrips on them. Had to use a special stud removal tool that I borrowed from a mechanic friend.

I also bought a longer timing chain (92 links) in case the chain tensioner can't handle the additional 2mm stretch caused by the cylinder spacer.

In the meantime, I just found out that Kymco just released a new 300cc sports scooter that I can't afford:



It's also available in silver or orange. Liquid cooled and fuel injected. MSRP is $5,600. Wish I had the money for one of these things...

Anywhos, stay tuned!

[gearhead]

Ah hah! So you had to get the longer timing chain! What about an after market cam chain tensioner?

[Rippinyarn]

The Downtown came out last year to generally good reviews, but it's still just a bigger traditional scooter design in the rear suspension dept. And it sure ain't cheap! It's not a Blur competitor, I'd love to ride one, though.

Good luck on your build!

[babblefish]

Ah hah! So you had to get the longer timing chain! What about an after market cam chain tensioner?

I've never seen an after market tensioner and besides, I'm pretty sure the stock one will work out fine.

[babblefish]

Update:

The crankcase boring tool that I bought could not be used as received. I had to modify it because the cutting bit was too long to fit into the tool itself which meant it could not be bolted up to the crankcase. Then I discovered that the opening in the tool for the cutting bit was too small to allow enough adjustment of the bit for any cylinder hole bigger than 64.5mm. Unfortunately, I needed to open up my crankcase to 65.5mm. So, it had to be thrown on the lathe to open it up a bit.
Finally able to use the darn thing and I mess up the crankcase by taking too deep of a cut and made a 66.1mm hole.

Bugger! Ended up cutting into the oil return port and one of the cylinder stud holes. This stud hole also serves as the port through which the oil gets to the head. When done right, the wall thickness of the crankcase material at those ports should be a little under 1mm.

All fixable, but highly annoying. I'm going to close the return port with an TIG welded aluminum plug then relocate and drill a new port. For the cylinder stud port, not sure yet...possibly "JB Weld" or TIG weld a liner into the hole after opening it up a bit.

Ho Hum, that's what I get for being in such a hurry and trying to do this at 1 o'clock in the morning.

BTW: I could buy a new crankcase assy., but I don't really want to spend $260 because of my muck-up right now.

In other news, I bought some new Michelin Pilot Sport tires - 130/60 x 13 for the front and 140/60 x 13 for the rear. With the slightly greater ground clearance and stickier rubber they'll allow even better handling than the Blur is already known for. Also with the bigger diameter front tire, the speedodometer should be a little more accurate.

Gosh this is fun. When was the last time you heard the word "gosh" used?
More to come. I'll post pictures soon.

[babblefish]

Old thread, but this saga will continue...

I would also like to retract any negative comments I made about Scrappydogscooters. They're actually not that bad. My standards might be a bit too high for my own good.

[babblefish]

Just some teaser shots
Oh yeah, it's 180cc

[avescoots1134]

Use a modded air-box instead of a pod filter. CV carbs and pod filters don't play well together.

[babblefish]

Use a modded air-box instead of a pod filter. CV carbs and pod filters don't play well together.

I've heard that. Thanks for the reminder. I'll take a look at my airbox to see what can be done, but, I'm going to try the pod filter anyway to see for myself what effect it has.

[babblefish]

Shot of where I bored into the oil galley and the repair work done.

[babblefish]

Intake port of the new head is significantly larger than stock. This is after doing a bit of clean-up with a Dremel. I enlarged the hole in the plastic insulator plate that goes between the intake manifold and head to match the larger port size.
I just hope I didn't kill all of the bottom end power of the engine...

[babblefish]

Exhaust port is also significantly bigger, hence the need for a different exhaust system that has a larger diameter pipe.

[babblefish]

Nick of KS Power Nick mentioned in an earlier post that the 30mm NCY intake manifold is restrictive so I took a look and could see some areas that could be opened up and made better.
Pictured is the NCY manifold after some massaging with my Dremel. I also included a picture comparing the NCY and the stock manifolds.

[babblefish]

Pictures showing the difference between the 24mm stock carburetor (left) and the new 30mm carburetor. The new one is a direct bolt-on replacement including mounting points and electrical connection.

[babblefish]

Use a modded air-box instead of a pod filter. CV carbs and pod filters don't play well together.

Looked into fitting the stock airbox hose to the new carburetor. Old carb has a 42mm diameter inlet opening, new carb is 46mm. Hmm, what to do. Heated up the rubber airbox hose with a heat gun to soften it up, forced it onto the new carb, then let it cool. Hopefully it will hold it's shape. Just have to modify the airbox itself to allow more air in as the inlet port is pretty restrictive. Thanks again for the heads up avescoots1134.

This build has been both fun and a challenge, and I'm enjoying every minute of it. Learning a lot as I go along. I'll probably be ending up with a few new parts that I will most likely not use such as a brand new 59mm big bore kit (no crankcase modifications required to install) and an extra intake manifold for a 30mm carburetor. If anyone is interested, PM me, otherwise they're going up on eBay.

Note: The 59mm BB kit will not work in 125cc Buddy's. The piston wrist pin is too big to fit (15mm in a 150cc engine vs 13mm in the 125cc).
For a 150cc engine, the new displacement will be 160cc.

[babblefish]

This is a pic of my engine without the head installed showing where the piston sits at TDC (top dead center). I guess that's the correct position relative to the top of the barrel. If anyone knows differently, please let me know.

[babblefish]

I can see some light at the end of the tunnel...unfortunately, after I installed the engine into the frame I remembered that I needed to make an adjustment to the exhaust tappet clearance because I set the wrong gap, fooey!

[babblefish]

I seem to be talking to myself here, but just in case there are lurkers out there who might be thinking about doing some upgrading too, I'll continue.

The 30mm carburetor is physically slightly larger than the 24mm unit so it is a tighter fit. Looks like there's not enough room to fit the pod filter directly onto the carb, but I could mount it on the end of the original rubber tube that connects the carb to the airbox. Problem is, that leaves the filter out in the open for water and dirt to hit it. Guess I'll have to modify the airbox and use that. Oh yeah, the original clamp that secures the rubber tube to the carb is now too small. Have to go find a bigger one.

Details, details...

[chickdr]

It would be interesting to see what your 180cc would do against a stock ss220i...

[babblefish]

It would be interesting to see what your 180cc would do against a stock ss220i...

I doubt if it would do well against the 220i. As they say, there's no substitute for cubic inches, or in this case, cubic centimeters. Plus the 220i's FI would make it more efficient.

[babblefish]

Still coming along nicely, but still a lot of little detail work that needs looking into. Touching up the paint on the frame here and there and looking to install a cooling fan on the fairing in front of the oil cooler to help keep the engine happier. Bought a fan that came off a Kawasaki 250 from eBay and will probably make some kind of thermostatic switch to turn it on and off depending upon oil temperature.

Mounted my new tires (kind of a pain, but satisfying) and had them balanced at my local scooter shop (thanks Barry @SF Scooter Centre!). The balance job cost me a ton of money, mainly because I got a parking ticket while I was in the shop.
The new tires are Michelin Pilot Sport SC's, 130/60-13 front and 140/60-13 rear.
Looked at the Hooligan scooter while I was at the shop, wish I had the money to buy one...that flat bottom floorboard sure would be handy while on shopping errands.

One thing I won't have to worry about is whether or not the stock starter motor will be able to turn the engine over...it does. No, I didn't start the engine yet, still need to re-install the oil cooler/filter and lines, but it does crank over easily.

The Blur is nine years old now and some of the hardware is starting to look a bit tattered, so I've been replacing some of them with stainless steel.

Planning on installing an HID headlight, too. They're pretty cheap on eBay, but I don't know if they're any good. I don't trust anything that's too inexpensive.

I'll be leaving the center stand off the scoot for now. I kept touching down on it when making hard left turns. Sometimes hard enough to lift the rear tire completely off the ground. That's a lot of fun when you're right in the middle of a turn...NOT!

Getting close to take-off, but still need to find a suitable exhaust system; hopefully one that won't get in the way when making right turns.

The to-do list seems never ending...

[babblefish]

Well look'et what I found: http://www.ebay.com/itm/Power-High-Flow ... 90&vxp=mtr

A bit expensive, but it's washable and reusable.

Oh, and BTW, it fits the Hooligan too! (same OEM P/N as the Blur)

[babblefish]

My technical adviser laying down on the job...

[babblefish]

Oil cooler and lines reinstalled. Kind of hard working on a bike while it's sitting on the ground and motorcycle lifts are pretty expensive, so I made my own. It's basically a small floor jack with a 2x6 board bolted to it. A little bit wobbly, but it works. Truthfully, although the picture shows the whole scooter lifted into the air, I mainly use it to lift either the front end only or the rear end. Safer that way. I'm going to redesign it a bit to make it more stable so that I can safely lift the entire scooter into the air and work on it. Sure saves my back.

[babblefish]

Here are some before and after shots of the rear suspension support arm. Five years of storage in a damp garage and a cat peeing on it (eww!) did a number on it. Too bad I couldn't reuse the label that was on it when I repainted it. Can't find a replacement on the net, not even ScooterLounge.

[babblefish]

Decided that since I'm already doing so much work on the Blur, I may as well improve the front suspension too. I've always thought the front forks were a little too soft and underdampened, so off they came. I plan on installing a pre-load spacer and replacing the oil with 25-30W fork oil. I drained the old oil into a cup so that I'd know how much to refill with (spec is 95cc). The old oil was pretty much black, but at least it didn't smell like the cheap fish oil that I've come across in Japanese forks back in the seventies. There is what appears to be a drain plug at the very bottom of the forks, but it was so tight that I left it alone because I didn't want to risk breaking something. Besides, I needed to get to the spring anyway. Note that it is possible to remove each individual fork tube without having to pull the entire fork/triple clamp by loosening the pinch bolts on the triple clamp. I wanted to check the headstock bearings and grease anyway so I pulled the whole thing. Although there was grease in the headstock, the lower bearing balls were dry in mine. Good thing I checked since the lower bearings takes all of the weight load.

Some useful specs:

Fork oil: SAE 10W20, 95cc (95ml/3.21oz) per leg
Headstock bearings:
Upper - 26, 5/32" dia.
Lower - 19, 1/4" dia.