Smallframe engine build - 1974 Primavera
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Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Wed Feb 19, 2014 8:46 pm quote
Yea! DRT Runner tree has arrived, the build can commence!

But now I'm second guessing my primaries - is it worth the scratch to go straight cut or should I just rock the stock? This is the time to decide....

Ugh with the second guessing .
Addicted
'77 ET3
Joined: 05 Mar 2013
Posts: 564
Location: OC
Thu Feb 20, 2014 7:02 pm quote
sdjohn wrote:
Yea! DRT Runner tree has arrived, the build can commence!

But now I'm second guessing my primaries - is it worth the scratch to go straight cut or should I just rock the stock? This is the time to decide....

Ugh with the second guessing .
The benefit of running a straight cut primary is the ability to swap the cog on the crank up or down to alter your gear ratio without splitting the cases. A straight cut will translate a decrease power loss in the drive train vs. the helical cut. The gear whine is a bit noisy and rattles at times but its not obnoxious.

My stock helical primary had a bit of play in the cush drive so I replaced mine with a DRT 27/69. But you could also go for a cush drive repair kit and swap out the springs and gears instead, albeit a little more work but less $'s.

What DRT input shaft version did you pick up?

Short 4th,
Xtra short 4th,
or Xtra short 4th and short 3rd (i think this is the runner)?
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Thu Feb 20, 2014 9:03 pm quote
I went for short 4th only. I liked that 3rd would rev to 45 mph and didn't want to shorten it.

I decided to rock the helicals and move on. I installed the kick start gear, the quadrant, the loose gears today. I will do bearings on the fly side next!

image.jpg

Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Thu Feb 20, 2014 9:18 pm quote
Btw I'm hoping the short 4th is short enough, but it's hard to tell until it is too late. So far I've got short 4th, the DR cylinder, the lightened flywheel working as my power improvements, which should help a lot. I will make sure the squish is good and I will consider a foam filter on the carb. I figured final drive is now around 5.56 or so, up from 5.3.
Addicted
'77 ET3
Joined: 05 Mar 2013
Posts: 564
Location: OC
Fri Feb 21, 2014 6:29 pm quote
sdjohn wrote:
I'm hoping the short 4th is short enough, but it's hard to tell until it is too late <snip>
Ya, a 21 tooth on the tree should be good enuff for your tune.

What gear calculator are you using?

I've use this: gear ratio calculator

G'stuff to whoever created the spreadsheet, only thing missing is a mph conversion.
Veni, Vidi, Posti
px200 cutdown,px180,px150. Puch SR. Puch scooterette
Joined: 08 Apr 2009
Posts: 5109
Location: west aus
Fri Feb 21, 2014 7:43 pm quote
mr.j wrote:
[

G'stuff to whoever created the spreadsheet, only thing missing is a mph conversion.
just divide the km by 1.6 and you have miles



learned to drive miles cars on km roads so i find it easier the other way around
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Fri Feb 21, 2014 7:44 pm quote
There's a great one on the smallframes forum, but it doesn't have the tree I bought so I had to do that math by hand. I should pm that dude and have him add it. It's a really nice sheet.
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Sat Feb 22, 2014 9:51 am quote
Bearings in! Thanks Mr. J you can have your bearing drift back now .


image by john.headley, on Flickr

The DRT tree was too snug for the bearing, but nothing a little emery cloth and a gentle push from the rubber mallet couldn't solve.


image by john.headley, on Flickr
Molto Verboso
Joined: 24 Jan 2008
Posts: 1909
Location: Santa Margarita,Ca.
Sat Feb 22, 2014 11:24 am quote
It's true. Orange is fast!
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Sat Feb 22, 2014 12:55 pm quote
Totally faster than apple.
Sergeant at Arms
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: 21 Oct 2005
Posts: 7300
Location: The state of insanity, SoCal
Sat Feb 22, 2014 4:51 pm quote
bah! we all know that red is the fastest...

orange is definitely cooler, though.

source: own red PK, do not own anything orange.

-g
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Sat Feb 22, 2014 5:39 pm quote
Cases mated. Spent about 20 minutes looking for a "lost case bolt" only to remember it was attached to the bracket on the brake cable.


image by john.headley, on Flickr

Pull apart the clutch to install a Polini spring. I hear they are in between a Malossi and standard, so it seems about right:


image by john.headley, on Flickr

Polini at the right:

image by john.headley, on Flickr

Install the clutch, the nut on the primary and the clutch are both loose until I install the top end and can use a piston stop to torque them.


image by john.headley, on Flickr

Today's questions:
1) DRT tree came with a wavy washer instead of the tabbed one for the clutch nut. Is this OK to use?
2) How do I know how deep to drive the cylinder studs? They are through holes, so there is no positive stop. Medium loctite on these?

Thanks.
Molto Verboso
Joined: 24 Jan 2008
Posts: 1909
Location: Santa Margarita,Ca.
Sat Feb 22, 2014 6:52 pm quote
sdjohn wrote:
Totally faster than apple.
But not as simple as green.

Waves washer under nut. It will need a hit of dremmel on the id to fit. Red loctite.
Molto Verboso
Joined: 24 Jan 2008
Posts: 1909
Location: Santa Margarita,Ca.
Sat Feb 22, 2014 6:53 pm quote
And the torque setting is higher for the m11 shaft than the original m10.
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Sat Feb 22, 2014 7:03 pm quote
scootermarc69 wrote:
And the torque setting is higher for the m11 shaft than the original m10.
Any idea what torque to use?

The wavy washer threaded on , it seems like it will be fine as it flattens.

Thread lock on the primaries and cylinder studs too?
Addicted
'77 ET3
Joined: 05 Mar 2013
Posts: 564
Location: OC
Sat Feb 22, 2014 8:10 pm quote
Stock M10 nut with tabbed washer torque value is 28-32 ft/lbs. Since you are using an M11 without the tabbed washer, I'd shoot for 35 ft/lbs and use some loctite.

On the primary nut, I assume that you are going to use a tabbed washer = 36-40ft/lbs. Loctite is up to you here but the extra security of the washer helps.

Loctite on the cylinder studs are also dealers choice. Since they are open holes its less of a risk of fracturing a stud hole.

FWIW the only place I use loctite is the flywheel nut, I run tabbed washers on both primary and clutch nuts.

Looks good John!

@joshzingzing - I'm glad that my optimistic speedo is in km/hr and I gauge my speed with the flow of traffic and butt dyno. lol.
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Sun Feb 23, 2014 5:49 pm quote
Installed the piston to the rod today, rag is for those pesky circlips:

image by john.headley, on Flickr

Lap the mating surfaces of the head and barrel:

image by john.headley, on Flickr

Install the barrel.

image by john.headley, on Flickr

I tried several ways of measuring the squish. This way is a bit difficult, things tend to move. I also tried the solder through the hole method.


image by john.headley, on Flickr

I got 1.9-2.0 mm on my measurements. The DR head doesn't have much area to compress it, I am not sure I am getting a true measurement. Since it seems large-normal, I am going for it. The measurement was always in the doubled area of my twist, which means if I could get a twist all the way to the outside I think it would be narrower still. My solder looping technique kind of sucks.

Buttoned it up.


image by john.headley, on Flickr

I installed the exhaust studs (new from DR). I went to install the intake studs but they are kind of trashed, so I will have to source some new ones. I think it's a bunch of loctite on there. I tried using a die to clean it up but they are really just a mess, so bye bye.
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Sun Feb 23, 2014 6:34 pm quote
On the intake studs, will these exhaust studs work? (upper in picture) They have a shorter portion to go into the case, so I'm not sure if it is enough. The old one is on the right.


image by john.headley, on Flickr
Ossessionato
73 Rally, 74 Rally, 76 ET3, 80 P200, 63 Li125, 65 Li225 Silver Special, 86 Elite 80, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 3305
Location: Oceanside/ SF
Sun Feb 23, 2014 6:57 pm quote
What did you use for a flat surface to lap that?

It looks like a picture frame.
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Sun Feb 23, 2014 7:11 pm quote
Yes, the glass from a picture frame.
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Mon Feb 24, 2014 8:06 am quote
I thought of a simple modification to my squish measurement technique:

image by john.headley, on Flickr

I still get 2mm. I'm thinking this needs attention. Should it come from the barrel or the head???
Addicted
'77 ET3
Joined: 05 Mar 2013
Posts: 564
Location: OC
Mon Feb 24, 2014 7:25 pm quote
2mm squish is not too bad but not optimal, I would aim for 1mm - 1.5mm

I would just skim the top of the cylinder about 0.5mm - 1mm or so.
You might want to take an additional 0.1mm if you intend to use some sort of sealant (hylomar or hondabond) on the base of the barrel and cylinder head.

My squish was 1.7-1.8mm and thought about skimming the barrel but I just wanted to get the scoot together. I have read that the squish band tolerance that falls on the high side will give a better top end result. While a tight squish will yield a better low end torque.

You could run without a base gasket, see where that puts you.
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Mon Feb 24, 2014 9:02 pm quote
Yeah I pulled the head and will have a go at lapping it with 220-400-600. If I can get even 0.2 or 0.3 off it'll probably be fine.

Thanks for the input!
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Mon Feb 24, 2014 11:14 pm quote
Lap lap lap today. 220 / 400 / 600 grit.

1.4 / 1.52 / 1.52 / 1.65 last measurements at 4 corners. It's hard to get that 4th one, the band is narrow over there.

I call that done.
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Tue Feb 25, 2014 8:20 pm quote
Torqued down the primary nut and the clutch nut today. Installed the rest of the clutch bits and the cover. Done on the clutch side.

Next up stator, including points gap and timing.
Ossessionato
73 Rally, 74 Rally, 76 ET3, 80 P200, 63 Li125, 65 Li225 Silver Special, 86 Elite 80, 2015 HD Road Glide Special, 2011 Ural Tourist
Joined: 18 Jan 2012
Posts: 3305
Location: Oceanside/ SF
Tue Feb 25, 2014 9:55 pm quote
Sweet man. Home stretch
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Wed Feb 26, 2014 8:16 am quote
Yeah you can feel it now

I put the stator in last night after I posted. It's a real challenge to get those wires through the rubber plug thing and get it through the case. In the end, I couldn't find a way to seat the plug with the wires in so I had to take it all back apart and seat the plug and then pull the wires through. With a new plug, and 5 wires with ring terminals, it's a tight fit! Pic to follow.

Static timing and points gap next.... Fortunately I just went through marking up the flywheel and case before this, so I don't have to bust out the degree wheel.

I found some metal shavings from my primary gear in the clutch side when I went to torque it all down. Turns out a non-torqued nut on that gear plus having the cover on with no gasket = no clearance. I double checked the direction of my primary gear - shoulder is out and that's how my picture and the How to Restore Your SFV book show it, so it was just tolerance stack. I cleaned out the bits and tried with grease (on the cover as a check) again, and it seems to clear now. That took a few minutes of head scratching, I'll say.
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Thu Feb 27, 2014 8:19 pm quote
Set up the stator day.

First, dig out the non-lightened flywheel with timing marks. Set up the points gap. It took me a while to figure out the 0.4 gap specified was mm and not 0.040". Once I figured that out timing the stator got a lot easier!


image by john.headley, on Flickr

Then use the paper method to determine the opening point. From my last try at this weeks back, the paper releases about 2 degrees after the firing point as strobed on my bike. So I set up the stator so the paper released at 18 degrees BTDC. I'm going to run 20 degrees, stock ET3 timing. This is specified as OK on the SIP page with the DR kit. Since I run premium fuel all the time, I don't think this is high risk. If I get some detonation I'll readjust but I think it will be just fine.


image by john.headley, on Flickr

Take off the boring flywheel and put on the Hot Rod Al special. Done with ignition.


image by john.headley, on Flickr

Next up, grab a shroud from Motorsports, mine is a bit melted with a fastener location either melted or cut off. Grab some intake studs at the same time.
Molto Verboso
Joined: 31 May 2009
Posts: 1220
Location: NC, USA
Fri Feb 28, 2014 5:16 am quote
You might want to hook up the clutch cable before installing the wheel and exhaust to check the pull. After trying three different clutch springs and a four-plate conversion, I am back to stock for easier riding. A set of dog leg levers did help a great deal with the stout springs.

A teflon lined clutch cable also helped.

Great project report!
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Fri Feb 28, 2014 9:17 am quote
I had to pull the flywheel back off - forgot to lube the points felt .

Got started filing the Polini exhaust flange. There was a carbon trail from the port hole to the stud hole on the manifold. Got to make sure it's flat, like this:

Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Fri Feb 28, 2014 9:18 am quote
The Polini is too easy to live with compared with the bolted flange joint on the banana, so I'm starting with it on the bike. It's one bolt and a spring to get engine access. Plus, reading the Scootering exhaust test, it seems to do better than the banana anyway. I like the banana exhaust sound and character, but maybe I'll get a SIP one with the spring setup later.
Sergeant at Arms
Weird 80's Vespas & Cool Vintage Lambrettas
Joined: 21 Oct 2005
Posts: 7300
Location: The state of insanity, SoCal
Fri Feb 28, 2014 11:46 pm quote
sdjohn wrote:
Set up the stator day.

First, dig out the non-lightened flywheel with timing marks. Set up the points gap. It took me a while to figure out the 0.4 gap specified was mm and not 0.040". Once I figured that out timing the stator got a lot easier!

Take off the boring flywheel and put on the Hot Rod Al special. Done with ignition.
double check your timing/gap just to be sure-- the points cam on the lightened 'wheel may be slightly different thus causing you a headache down the line.

good job on taking a file to the flanges, those polini ones warp like crazy.

-g
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Sat Mar 01, 2014 9:48 am quote
Thanks Greasy.

I did run this briefly before in place of the standard one and didn't notice any change as far as knocking, etc. There's no meat left to carve timing marks in, so if I do it I need to redo the timing marks thing using a fin and a new spot on the case. Timing to a fin is strange though, as it's curved and even less precise than a mark on the flywheel edge. I went through this on my Serveta. It is the right way to do it though, of course.
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Sat Mar 01, 2014 4:59 pm quote
OK so back to the filing:

image by john.headley, on Flickr

Then I lapped it to get it smooth. New gasket with copper RTV and on it goes.


image by john.headley, on Flickr

Then a quick cleanup of the intake and some hylomar and on it goes:

image by john.headley, on Flickr

Install the stator wires to the junction box (later I added the coil wire):

image by john.headley, on Flickr

I put the shroud on and routed the wires but forgot to grab a pic. Oh well, there will be one once the shroud goes on. Speaking of the shroud, it was too rusty to go back on untouched. I gave it a cleanup as best as I can without a blasting cabinet and on with some primer today:


image by john.headley, on Flickr

If the imperfect cleanup comes back rusty in a year or two it's easy and accessible to redo. Couple of screws and find a friend with a cabinet. After it dries thoroughly I can give it a shot of flat black, it will be miles ahead of where it was.
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Tue Mar 04, 2014 10:17 pm quote

image by john.headley, on Flickr

It's in.

I went with the felt on the intake as the diagram shows crowd, but I'll back that up with the Hondabond on the carb slits. What I do notice is that the felt helps the sleeve fit nicely over the manifold and centers it. It feels correct, whereas with it on the other side the sleeve is a crappy fit to the manifold and the tab wants to fall through the slit / retainer easily.

Speaking of the carb, I'm thinking 82 main jet as a starter, am I too low? I have 82 and 85 in the jetting kit.
-DR130
-Polini kidney
-19.19 carb
-reduced filter material (thanks for the suggestion spiderwebb)

Will I need a 48 pilot or will the 45 work? Is the 48 the same as a Lambretta SH1 48? They look mighty familiar....
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Thu Mar 06, 2014 9:17 pm quote
So I've been painting a few things. The flywheel cowl got finished up:

image by john.headley, on Flickr

I got a replacement fuel tank from my friend Dan. It's super clean inside but was about 3 colors or more on the outside. I nearly caved and used it as is but I felt guilty and gave it a clean and a coat of flat black:

image by john.headley, on Flickr

My old tank has Kreem inside it and I can see some breaks in the coating, which makes me nervous. He gave me a killer deal on it so I had no reason to continue with a questionable tank.

I went ahead and made my wiring connections and installed the flywheel cowl tonight. The plastic hooks for the wiring on the shroud are kind of useless to hold in the wires - the metal dell clips do the job and I may add a selective zip tie or two. I'm not above zip ties .


IMG_0357 by john.headley, on Flickr
Mr. Clean
P,SUPER,V90, 50 Special
Joined: 27 Jul 2010
Posts: 10207
Location: This is't my locker!
Fri Mar 07, 2014 7:30 pm quote
Looks cool john! Large door you lucky!
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Fri Mar 07, 2014 7:41 pm quote
Thanks man, flat black makes everything look good!
Addicted
GL, PK, PE200, Rustbadge
Joined: 24 Apr 2012
Posts: 713
Location: Deep in the heart of Texas
Fri Mar 07, 2014 9:10 pm quote
Nice work. Now I'm going to rattle can my gas tank. PO had a VBB tank without an oiler. Found a Sprint take with oiler but a different color and I was going to just use. Now I'm painting. Good job and nice updates on your project.
Ossessionato
1 Empty Garage Space, 1974 Primavera, 04 Ninja 250
Joined: 04 Apr 2013
Posts: 4021
Location: San Diego, CA
Sun Mar 09, 2014 7:29 pm quote
So it was another day of progress over here. It's cable time, so out comes the headlight to deal with gear cables and clutch cables. What's the story with this thing anyway? The bulb doesn't appear to come out of the back but someone has sealed the glass with silicone. Does this come apart when I want to change the bulb out? Is it just a bulb in a socket in there?


image by john.headley, on Flickr

New cables run through for gears and clutch. I had a bit of a panic when I saw the outers had slipped down a bit then I realized I could just put a trunnion on the other end and pull on the nib on the headset end. Sorted.


image by john.headley, on Flickr

Time for fuel tank work. Have to pull the fuel tap from my old tank (it's a brand new tap) and install in my new tank. The fuel tap tool had to be modified to work with smallies, note the chopped off bit.


image by john.headley, on Flickr

The tank looks way better in the photo than in reality, but here it is after I seated my carb:

image by john.headley, on Flickr

By the way I've joined the use a felt on both sides crowd on that carb flange. I didn't like the way it was seating without it so I pulled out another and installed it on this side.

Soldered up the long ends and chopped them short. I need new side cutters, they didn't do a totally clean job as I wanted them to. No problem.


image by john.headley, on Flickr

Buttoned back up the headset. I've put on a mirror mount that works better for me. The fancy chrome ones I got are totally flat, which points the mirror toward the ground and makes it near impossible to adjust and be useful. So I ditched it for this black triangle of bent metal that was on my P when I got it. Does this look familiar to anyone? They work well but I would like to get a right hand side one since I have 2 mirrors.


image by john.headley, on Flickr

Sucky chrome one that looks good but doesn't work:

image by john.headley, on Flickr

Hub on, waiting for my hub holding tool that I had a friend weld for me at work out of bar stock and a scrap wheel. I don't understand why Vespa guys don't use these more, they are a mainstay in the Lambretta world. I'll post a picture of it after I get it.


image by john.headley, on Flickr

Oil filled. Almost there!!
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