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Andrew ITA

150 LD MKII - Build thread...from rust to glory

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I both hate and love following this thread. Hate that I don't own this LD and have the talent to do a restore job like this and the pictures alone tell you why I love it. Every time I log on this is the first thread that I look for to see the latest update. Best of luck with it on the road. If you get it to run as good as it looks that will be one fine LD.

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Thanks! Oh well, it takes a lot of effort but it's not impossible...also I haven't made it easy on myself by starting from a rotten piece of junk

 

 

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All in all it went well, everything work except the following:

  • Jetting is way too rich, top and bottom. Will keep it as is for now as I break in the engine, then I'll fine tune it when I switch to synth mix at 4%
  • Gears clunk, I need to tighten the clutch cable a little
  • Horn not working at all. It's a 6VAC that I'm using with the 12V varitronic, it should work but instead it does nothing. When lights are on and I try to use it, lights turn off. Mmh
  • One seat spring broke off, easy fix
  • Some dark goop seeping from the exhaust flange at the cylinder. The flange is super tight and I've used a high-quality copper gasket, it might just be because of the extra assembly lube I used. I'll clean it up and see how it goes for the next few miles.

All in all I'm happy, no major problems for now.

 

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Do you guys know any trick to seal the exhaust flange at the cylinder?

I remember back in Italy I had a sort of black goop that would seal exhaust couplings...is there any similar product here in US you can suggest?

I'm running 6% BelRay mineral for just this first tank to break-in the engine, then will switch to 4% synth. However, I think the issue is really the jetting, it hits the wall at around 70% throttle. I'm way too rich, will try 10 points less and see what happens. It really sprayed everywhere :lol:

 

 

IMG_20171102_133121408.jpg

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The LD should have a Copper ring exhaust gasket yes?

Anneal that sucker so it's good and soft. Also use some copper RTV on it.

6% mix is a lot of oil.

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Yes it's copper, I special ordered it on purpose since the aluminum ones usually lead to leaks. Great idea about annealing it, I'll try that along with the copper paste.

With regards of the mix, I follow Tino's recommendations for the shaft drives..."quantity is better than quality" and stick to 6% for the first tank,then down to 4% mineral. Having said that, I noticed it doesn't burn that well here with ethanol fuel and lower octane. What do you usually run on LDs?

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I started following Tino's 6% for break in and only made it 1 tank before I abruptly dropped it to 4%. I use a full synthetic and it's much happier at 4%. I also used the updated crank with the small end bearing instead of the brass bushing that came standard. If I had that crank, I'd probably run 5%.

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Ok so this is what I'm going to do to fix the issues.

The original jetting with the MA19B4 was 45 MIN and 72 MAX. I'm now running 50 / 82 with a PHBG 21 AS. 

What I'm observing is: exhaust leak, throttle only takes 70% of travel until engine hits the wall, in 3td gear is about 40mph. Bottom/mid is a little weak. 

Spark plug looks like this, a little dark (but not too much), oily.

 

IMG_20171106_115437708 (1).jpg

 

I will try this:

-Drop the max jet to 77, which is 5 less than what I'm currently running and 5 more than the standard spec.

-Needle down 1 slot

-Flush tank and run 4% mix w/ Motul 710

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With regards of the exhaust leaking at the flange, I've called some "seniors" who told me something I didn't really know...

There are 2 types of exhaust flanges:

-OEM type

-"import" type

The "OEM" type has a thick, machined flange. It requires a copper seal, you tighten it then let the engine get up to temp, then tighten again for an additional 1/4 to 1/2 turn

The "import" style has a thin 0.8mm flange. This requires the use of the alu/rubber "sandwiched" seal. The only way to seal it is to tighten it moderately and use a liquid gasket to aid sealing. If it leaks...avoid over-torqueing it and just wait until the deposits seal the leak.  If you tighten it too much, chances are you deform the flange and it will leak even more.

 

I'll check it out and let you guys know how and if it works

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Ok this is what I found.

This is my exhaust, it's a new repop from CL. Notice the thin flange.

IMG_20171106_130204044_LL.jpg

 

Here is a picture of an OEM flange, notice how thick it is, appears to be machined instead of pressed

20087230122_P1000277.JPG

 

And this is a comparison between the two gaskets. The CL one is thicker and much softer, a rubber gasket is sandwhiched between two aluminum rings

IMG_20171106_130249396.jpg

 

You never stop learning with these LDs

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Today I finished the last detail...my grandpa used to say that doing things right always helps you save half the time...in fact I tried to fiddle with the throttle cable that was clearly too short. trying to reroute, bend it here and there...but ended up wasting time and the LD was still accelerating while on the stand. 

So I came up with this solution, hope it will help other folks that run PHBGs on these scooters.

You need a 90 degree and a 40 degree elbow kit.

P1080699.JPG

 

If you are good at machining, you can build an adapter (male M5x0.75 to female M6x0.75) or if you  can't, you can buy a small aluminum spacer (I found it at ACE) that you can use as a sleeve connector.

I drilled it with a 15/64 bit, which is about 5.95mm. Once you make the hole you end up at around 5.97 while the Dell'Orto elbows are 6mm OD, just perfect for an interference fit.

 

I simply heated the connector and pushed the two elbows in by hand

P1080702.JPG

 

As you can see the cable ends in a better location, having enough slack to operate correctly

P1080705.JPG

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Beautiful job on this. Not into LD models, but that thing is good looking and sounds even better. Sure hope to see it in person some day.

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5 hours ago, upjettr said:

Beautiful job on this. Not into LD models, but that thing is good looking and sounds even better. Sure hope to see it in person some day.

thanks! Took forever, but it was worth it...I'm very close to finish it, will post the final pics soon!

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Speaking of finishing...I was able to fix the exhaust leak at the cylinder, now I got one at the side inspection covers...more copper gasket will fix it. 

Anyways, just wanted to share my quest for the perfect tune up.

Even if the jetting is off, the PHBG is way better in terms of idle, throttle response and linearity, I think it was a good bet.

As you can see I started pretty rich.

Carb.jpg

After the first ride, this is what I observed:

-Lots of smoke

-Weak low range

-Idle Mix screw totally ineffective

-OK midrange

-Engine Can't take more than 70% throttle 

-Max speed 35mph

 

Spark plug looked like this, evidently rich but not that far off.

IMG_20171106_115437708 (1).jpg

 

 

For the second test, I performed these changes:

-Change mix to 4% Synth

-Dropped 5 points on main jet

-Dropped 5 points on idle jet

 

Results:

-Normal smoke levels, almost gone when engine warms up

-Ok low rpms

-Idle Mix screw improved, but still not really effective

-Ok midreange

-Top range improved by  10%, engine still can't take more than 80% throttle

-Max speed 41mph

 

The spark plug looks like this. Richer than before, I think because of the drop in oil to 4%.

IMG_20171113_144421104_HDR.jpg

 

 

Tomorrow, before dropping 5 more points on main and idle, I will try running the engine without air filter (to see if the box restricts the air intake too much) and inspect the exhaust, since I have to open it anyways to seal the inspection covers.

 

 

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...almost there! Unfortunately weather in TX is not helping the process, but finally I've narrowed it down to a point where I can do all the fine tuning within a day.

These are my findings:

-The Malossi filter was restricting air intake, the Polini free flow changed everything

-Pilot jet: 50 (45 is too small, 55 is too rich)

-Main Jet: now I'm running 94 and it's decent. A little slow in in peaking but I got to 45mph, I think I'm still missing 3 to 5 mph

-Lower than 90 and it's starving fuel, losing about 5/7 mph

-96 and higher it floods and doesn't rpm high enough, losing 5/7 mph

So now I just need to fine tune it, knowing it's in the 90-95 bracket.

 

Spark plugs:

-B6HS: too hot

-B7HS: still a little too hot

-B8HS: this will be my next step, I placed an order already, will see when it arrives

 

This is with 94 main, after 4 miles, mostly at WOT

 

P1080724.jpg

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