Installing Polini 165cc cylinder kit on Stella 4T

[lifebeat]

Hello again, sorry to be bugging you guys with so many questions lately... You guys are very patient

So, I've got my cylinder kit in the mail right now, but I'm trying to find some info on actually installing it. I've done a bunch of cylinder swaps on Yamaha 2T scooter, but never on a small 4T like this one.

My main question is : Can I just remove the cylinder head timing sprocket, and then let the chain pass through?, or will this create a mess with the chain tensionner?

Also, if this is the case, I'm thinking of aligning the flywheel mark on the fan shroud mark for TDC, but once I remove the head, are there any marks on the camshaft that will ensure I don't mess up timing on reassembly?

Lastly, can I do this with the engine on the frame, or shouldn't even mess with it and take it off from the start?

Thanks!

Luc

[JohnKiniston]

I've not done a 4T Cylinder swap yet but I'd recommend taking the engine out of the frame. I don't know if there is enough clearance between the engine and the frame to get the cylinder out otherwise.

It's sorta workable on a 2T but even then I'd drop the engine and not mess with taking the studs out.

[viney266]

Agree with John, it is going to be easier with the motor out I think. It isn't a terrible motor to take out ( well at least the 2T isn't). I haven't had a motor out of a 4T yet either.
If you are not "happy" with the timing marks you have , remember you can always make your own, just simple scratches in metal work to see that it all goes back together properly. Timing is everything in a four stroke.

[az_slynch]

The flywheel is keyed to the crankshaft and the pulser coil is bolted to the case outside the flywheel, around the 12-1 o'clock position. No need to scribe the flywheel. You will need to be sure to line up the camshaft and crankshaft when you put it back together, though.

Reference page 118 of the service manual for info on this.

[lifebeat]

Wow! Thanks for your answers guys! I didn't realize this manual was here! I've been looking for it.

I thought this cylinder swap was going to be an easy saturday morning project... I'll have to see if I tackle it now or wait for winter...

[JohnKiniston]

If you wait long enough Sean or I are bound to do it eventually

But if you don't wait you get to be first. TAKE PICTURES!

[lifebeat]

I'm just debating if I can go without removing the clutch side, and just remove the tensioner, which "should" give me enough slack to remove the camshaft sprocket...

So you're saying I could be the first at something here?

[JohnKiniston]

First in north America possibly?

I know the guys over on the LML UK forum have the 165cc kits installed but most if not all seem to be put on by dealers.

[lifebeat]

Pfft! We fear not on this side of the ocean!! Let me clear out my mess of a work bench!!

[misterbrackets]

Hey lifebeat --- how did the installation go with the 165cc kit? (this is an old thread, but can't hurt to ask)

Has anyone else tried fitting one of these?

[misterbrackets]

After reading enough favorable reviews on the LML UK forum and not finding enough negatives, I decided to order one of these 165cc cylinders. It arrived a couple days ago and I'm planning on installing it this weekend.

The directions that came with with the kit are very minimal. Basically, they outline the placement of the rings and rotation of the ring gaps on the piston, but not much aside from that.
(The Stella shop manual seems to have most of the info I need, though.)

The new piston, on the top, has an indentation on one side and an arrow on the other. I'm assuming the arrow points towards the exhaust. (?)

The only other thing I'm a little worried about is the timing/chain when putting it all back together. Looks like there are markings that should tell me where TDC is, though - according to the shop manual. - inside the motor, not just what's on the flywheel.

Looks like I have everything I need, though. Nothing seems to be missing and came with new gaskets, etc.

Any other words of wisdom or things I should be careful of when doing this? Special tools? Etc? Thanks

[Neurotic-Hapi-Snak]

Second pair of hands/set of eyes? Do you have a brother/sister/cousin/friend that likes working on cars or engines?

[misterbrackets]

Good call ...... I may be able to call on a neighbor who likes to work on cars if I get stuck in a bind. I took the engine out last night and it went pretty smoothly. Putting it back in is going to be a little harder .... most likely when I'll need that second set of hands. Tonight I'm hoping to tackle the cylinder swap.

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[Tipper]

If you are on facebook join the LML owners club GB group. A member 'Dave Tablet Smith" has just fitted the kit himself and will probably have a few pointers for you.

[misterbrackets]

Thanks Tipper! I've got the new piston/cylinder installed in the motor - went smoothly for the most part. But now I've hit a snag with the timing chain tensioner. I didn't need to worry about it when taking it all apart, but putting the chain back on is a different story. The center slotted screw of the tensioner doesn't appear to do anything (it seems like a cap more than anything). When I remove it, I can see a small ring with notches around it, but I don't want to try anything until I know whether or not that's the screw I need to turn. (Too far along now to screw something up). I'll join the LML forum and see if I can connect with the fellow that just fitted one of these. Thanks again

[Tipper]

Pm me your email address and I'll ask him to drop you a line.

[misterbrackets]

So, after a couple minor hang-ups, got the 165cc installed and it's running great! It's too early to say how much of an improvement it is since I'm trying to go easy on it for the next 300 miles or so, but I will say that it's an improvement. There are two hills in particular that I ride on my way to work and there was a definite increase in enthusiasm on the part of my Stella riding up those. So, yeah.... I would say it was worth the time and trouble. Looking forward to seeing how it performs after the break-in period.

I did run into a couple issues when installing it, that I think a more experienced motorcycle mechanic would have gotten past a bit easier, but I don't think installation is beyond anyone with some patience and basic mechanic's skills. If anyone is interested, I can list the tools I found especially useful (nothing out of the ordinary, really) and other general tips/info. The most important advice would be to take your time and break the project up into 2 or 3 days.

Believe it or not, the most frustrating thing I encountered was getting the new piston in the cylinder. You need to compress those tiny rings with your fingers to slide it in, and at the same time, make sure the ring gaps stay situated at a 120 degree offset from one another. (They like to slip around). The solution I found was installing the piston in the cylinder BEFORE sliding it on the dowels, then, leaving the end of the piston sticking out with the hole exposed, attach the piston to the crank with the pin. Much, much easier. Just make sure the flywheel is secured when you do this, or the piston is likely to get pulled out of the cylinder when you feed the timing chain through the block. Oh, this happened to me 2 or 3 times

All in all, a fun project.

[gburbank]

As the warranty will expire this winter, I ordered the 165 kit along with the polini pipe and carb. I have a sidecar, so any extra oomph will help. How has the engine settled in now that you have a few miles on it?

[misterbrackets]

Sorry for a slow reply to your question..... haven't been on the forum to often lately. But the engine has been settling in nicely with the 165 kit. There is a definite improvement, but not a huge difference. Though my Stella seems to be running the best it has since I've started riding it. (I've put about 8k on it, 1k with the 165 kit)

[gburbank]

Thanks for the reply. With the sidecar, even a little more oomph will make a difference.

[Neurotic-Hapi-Snak]

Sorry for a slow reply to your question..... haven't been on the forum to often lately. But the engine has been settling in nicely with the 165 kit. There is a definite improvement, but not a huge difference. Though my Stella seems to be running the best it has since I've started riding it. (I've put about 8k on it, 1k with the 165 kit)

I noticed from the picture you are still using the stock carb, are you still using the stock exhaust? That may be why you haven't seen a large increase.

Also the 165 kit will increase mostly down low because of its larger squish band and higher compression.

[djp4059]

I'm also looking for a little more power, so I too have purchased the Polini 165cc big bore kit. I've also purchased an IHI RHB31 VZ21 turbocharger (the smallest turbocharger I could find) and an Electronic Fuel Injection kit. The EFI will be easier to tune with the turbo than a carb. The challenge will be trying to figure out where to install the turbocharger.

I still need to get a Boost Gauge, maybe a Blow-off valve and I'm pretty sure I don't need a Intercooler (I've read that Intercoolers are only needed for engines that are on constant heavy load).

My only worries are:
1- Will the crankshaft hold up.
2- The heat the turbo will create.
3- If I'll have enough juice to run the EFI, a electronic fuel pump and electronic oil pump.

This will be my winter project, so I have plenty of time to figure this out.

[PeteH]

Whoa. If I were you, I'd budget for a steel plate under the seat for when it assplodes. But good luck!

[BuddyRaton]

I'm also looking for a little more power, so I too have purchased the Polini 165cc big bore kit. I've also purchased an IHI RHB31 VZ21 turbocharger (the smallest turbocharger I could find) and an Electronic Fuel Injection kit. The EFI will be easier to tune with the turbo than a carb. The challenge will be trying to figure out where to install the turbocharger.

I still need to get a Boost Gauge, maybe a Blow-off valve and I'm pretty sure I don't need a Intercooler (I've read that Intercoolers are only needed for engines that are on constant heavy load).

My only worries are:
1- Will the crankshaft hold up.
2- The heat the turbo will create.
3- If I'll have enough juice to run the EFI, a electronic fuel pump and electronic oil pump.

This will be my winter project, so I have plenty of time to figure this out.

Please start a build thread. I know that I and probably others would love to follow!

[az_slynch]

I'm also looking for a little more power, so I too have purchased the Polini 165cc big bore kit. I've also purchased an IHI RHB31 VZ21 turbocharger (the smallest turbocharger I could find) and an Electronic Fuel Injection kit. The EFI will be easier to tune with the turbo than a carb. The challenge will be trying to figure out where to install the turbocharger.

I still need to get a Boost Gauge, maybe a Blow-off valve and I'm pretty sure I don't need a Intercooler (I've read that Intercoolers are only needed for engines that are on constant heavy load).

My only worries are:
1- Will the crankshaft hold up.
2- The heat the turbo will create.
3- If I'll have enough juice to run the EFI, a electronic fuel pump and electronic oil pump.

This will be my winter project, so I have plenty of time to figure this out.

The crank will probably crap out, plan on upgrading the bearings (including the big end).

Separate oiling system for the turbo. Keep the clutch scuzz out of the turbo's oil ways. Maybe include an oil cooler for it.

Look at performance 7-spring Vespa clutches. You will kill the stock one.

Neat concept, though! A hot tamale of a 4T might finally get the interest of the vintage community.

[gburbank]

Yes, please! a build thread with photos on that turbocharger as you are CERTAINLY breaking new ground on this one. Also sources for the naughty bits as you purchase them and (if it's not asking too much) details on any custom machining you have done in the process. There are racing cams available. For now, I am trying to gain a little more muscle on the hills (the sidecar is a constant load) and better use of fourth gear, so my winter build is :165 kit, polini carb, polini exhaust, stronger clutch springs (for now) so while I am expecting modest gains, I have reasonable expectations. If you can figure out a way to transform a stella into something that smokes like the peugeot jetforce compressor, you've got a LARGE audience!

[BuddyRaton]

The crank will probably crap out, plan on upgrading the bearings (including the big end).

Separate oiling system for the turbo. Keep the clutch scuzz out of the turbo's oil ways. Maybe include an oil cooler for it.

Look at performance 7-spring Vespa clutches. You will kill the stock one.

Neat concept, though! A hot tamale of a 4T might finally get the interest of the vintage community.

Might want to contact Al at Hot Rod Scooters about upgrading the crank, he does great work.

I agree with the performance clutch. I did have a new Cosa Newfeld asplode after 1,000 miles on CBR 2012. The retaining ring blew out.

Now I'm using an MMW basket and Newfern EVO plates. Don't forget to rough up the steel plates to give them a bit more "tooth". It shifts like buttah!

[BuddyRaton]

Also consider higher rated tires. Most 10" tires are rated for 62 MPH. On my heavily modified bikes I run tubeless SIP performers which are L rated to 75 mph

http://www.sip-scootershop.com/en/produ ... +_79590000

[viney266]

As to the turbo kit.

1.) replace ALL the bearings in the motor with good quality ones ( not from India or China)

2.) Send the crank out and have it balanced and welded at the very least. I know guys who can do that if you need help.

3.) Innercooler adds "cool" factor but really not needed with low boost in this case. The manifold to run it is going to be tough enough to fab. You need to find a guy well experienced with a TIG who knows how to fabricate ( I know a few of these as well).

4. Controlling timing when it comes up on boost. The FI will help, but you will also need a "tuneable" ignition for the boost. OR keep it low 4-5 lbs and run really good fuel.

5.) oil cooler is a great idea, you will need it and the more oil the better.Run the best stuff you can, too.

Good luck with the project, save more money than you think you will need, and HAVE FUN. expect it to break and try to make sure it doesn't .

[Stilts]

I'm also looking for a little more power, so I too have purchased the Polini 165cc big bore kit. I've also purchased an IHI RHB31 VZ21 turbocharger (the smallest turbocharger I could find) and an Electronic Fuel Injection kit. The EFI will be easier to tune with the turbo than a carb. The challenge will be trying to figure out where to install the turbocharger.

I still need to get a Boost Gauge, maybe a Blow-off valve and I'm pretty sure I don't need a Intercooler (I've read that Intercoolers are only needed for engines that are on constant heavy load).

My only worries are:
1- Will the crankshaft hold up.
2- The heat the turbo will create.
3- If I'll have enough juice to run the EFI, a electronic fuel pump and electronic oil pump.

This will be my winter project, so I have plenty of time to figure this out.

The crank will probably crap out, plan on upgrading the bearings (including the big end).

Separate oiling system for the turbo. Keep the clutch scuzz out of the turbo's oil ways. Maybe include an oil cooler for it.

Look at performance 7-spring Vespa clutches. You will kill the stock one.

Neat concept, though! A hot tamale of a 4T might finally get the interest of the vintage community.

You'll still hear, "But it doesn't SOUND right, does it?"

[djp4059]

Where is a good place to order the 165cc big bore kit. I tried Scooterpartsco.com but they don't have it in stock and sent me a refund for my order. I guess they can't get it.

[Stilts]

Where is a good place to order the 165cc big bore kit. I tried Scooterpartsco.com but they don't have it in stock and sent me a refund for my order. I guess they can't get it.

SIP apparently still has some in stock

http://www.sip-scootershop.com/en/produ ... +_13000010

[Neurotic-Hapi-Snak]

Rob Hodge at Hodgespeed will hook you up with 165 kit and other goodies from SIP, I got one on order with him currently. As someone how has ordered from SIP directly 3 times now, don't order from SIP direct, order through Rob. Ordering directly from SIP is a PIA.

On the whole turbocharger idea, although a cool idea, I think will be way too much work. I would start with the basics, cylinder kit, big carb, exhaust; then move onto head mods like porting, bigger valves, aggressive can profile; finally maybe a long stroke crank if you can get one made or modified.

[djp4059]

Rob Hodge at Hodgespeed will hook you up with 165 kit and other goodies from SIP, I got one on order with him currently. As someone how has ordered from SIP directly 3 times now, don't order from SIP direct, order through Rob. Ordering directly from SIP is a PIA.

Your not kidding about SIP, just trying to register an account was a PIA. I sent an email to Ron Hodge about ordering thru him. Thanks for the info. Update: Ron already emailed me back with a link to his website to order the kit. Order has been placed. Thanks again.

I already have the turbocharger, oil cooler, oil pump and EFI kit, even bought a new MIG welder to weld up an oil reservoir and the tubing for the exhaust. Once I pull the engine apart I'll figure out which bearings I'll get (I'm thinking roller bearings for the crank) and I'm also looking at a BGM superstrong 10-spring clutch, they're kind of expensive though. Already figured out where I'll get the exhaust tubing and aluminum intake tubing and neoprene connectors. Haven't decided anything about the crankshaft it self yet.

I've done stuff like this on cars before, this will be the first time I've done it on such a small engine. I'm just doing this for the fun of it, something to do over the winter.

[Neurotic-Hapi-Snak]

So you already know what you're getting yourself into, that's good. I've never installed a turbo but I know it requires a lot of work and can quickly trash a motor if not done right.

You plan on any head modes? I want to do some porting but want to wait till someone with a little more experience tries it and can advise. Bolt on part are one thing but irreversible mods are different.

[Stilts]

I've ordered from SIP probably half a dozen times and have never had a problem. Weird.

Good luck with installing the kit!

[djp4059]

The problems I had with SIP were, first off, entering billing address and delivery address, after filling all the info and hitting next, the same screen would come back up like I forgot to enter some info somewhere, but I had everything filled out the way they wanted it. I don't remember how many times I kept hitting next before it finally took. And then for some reason when I tried to order using PayPal, it would come back saying "could not complete order refer customer to PayPal". I used PayPal at Hodgespeed and it worked fine. Also Hodgespeed charged the same price as SIP for the kit and the shipping is cheaper. So as long as Hodgespeed charges they same price as SIP, I'll just order anything I need from SIP thru them.

Turbos aren't that hard to install, its just finding a place to mount it. Ideally you would want it close to the exhaust discharge from the head for maximum flow. But there isn't much room under the Stella to mount it close to the head unless I install it where the muffler is and modify the muffler and mount it some other way. But since I'm thinking that I don't need a lot of boost, I'm looking at taking the airbox off and mounting it there somehow and making a new splashguard.

The hard part is probably going to be the EFI, there are a lot of wires and sensors for it. But it looks pretty straight forward, just got to follow the instructions.

As far as modding the head, I doubt if I'll need to, the turbo will do all the work. The turbo also has an adjustable wastegate and I'll have another pressure relief valve on it so I highly doubt I'll blow the engine. And I'm not trying to build some kind of rocket scooter, I just want to be able to climb hills with out losing speed with this sidecar attached.

[gburbank]

of course, a 200 cc lml 4t would fit nicely, power you up the hills, and can be had for about $1,900 delivered, all without risking the assplosion. All the naughty bits could be added without compromising the engine.
It's the cost, of course, that set me off to the 165 cylinder approach first.
If you're curious, the engine itself was 950 english pounds, plus crating and shipping of another 200-300 english pounds. Then of course you would add all the other items on the goodies list.
Yes, it will fit in a 150 frame, with a longer clutch cable and engine mount doohickey.(which they have)


http://www.lmlparts.co.uk/TECH_07.html

The turbo build is very intriguing, although outside my current level of mechanical expertise. I will follow your progress as posted, of course, because ya just never know. Thanks for being the willing and adventurous lab rat for the rest of us out here.