[SOLVED] Feedback on purchase/jetting/install for going to 70cc BBK

[245luigi]

Yes I installed by kit at the end of november. Basically I soaked up as much info as I could from here and other forums/resources. Then I watched the a 2 stroke bbk install video on youtube probably 10 or so times. Then went for it. Went without a hitch. She fired up first crank. Still working on tuning though. Ive only worked on the bike once since the initial install as its cold as hell here in Baltimore and I have no indoor work area. The bike is at my parents house about 2 hrs away. Ill probably bring it back up here beginning of March

[JJJoseph]

Heres a link to my photobucket so you can look at what a real deal scooter guy does.

This guy's an unbelievable blowhard who takes photos at the local repair shop and posts them while he boasts about what a clever and helpful guy he is.  Don't trust anything he says.  Anybody who doesn't know how to diagnose a simple 2-stroke has got to be a total pretender.  How are you enjoying the dialog, LoveMyKymco?

[Vivo]

This guy's an unbelievable blowhard who takes photos at the local repair shop and posts them while he boasts about what a clever and helpful guy he is.  Don't trust anything he says.  Anybody who doesn't know how to diagnose a simple 2-stroke has got to be a total pretender.  How are you enjoying the dialog, LoveMyKymco?

And you?

[245luigi]

I'm going to install the 19mm Dell'orto carb in hopes of alleviating my tuning issues, and maintain the stock airbox if possible. I have never installed a new carb before. The Malossi kit for kymco does come with a throttle cable. Do I need to use this one, or will I be able to use the throttle cable already going to the carburetor?

[LoveMyKymco]

This guy's an unbelievable blowhard who takes photos at the local repair shop and posts them while he boasts about what a clever and helpful guy he is.  Don't trust anything he says.  Anybody who doesn't know how to diagnose a simple 2-stroke has got to be a total pretender.  How are you enjoying the dialog, LoveMyKymco?

Come to St Louis. Why would I take shots of someone elses shop when I own the building. Simple I dont need to argue I have real world proof.

[LoveMyKymco]

I'm going to install the 19mm Dell'orto carb in hopes of alleviating my tuning issues, and maintain the stock airbox if possible. I have never installed a new carb before. The Malossi kit for kymco does come with a throttle cable. Do I need to use this one, or will I be able to use the throttle cable already going to the carburetor?

You will need that cable as it will mate to the new Del carb and your splitter wire going to the old carb and the oil pump.

[LoveMyKymco]

Is this the carb you got? I run the Athena racing Del on a Piaggio LT50 Hi Per2 engine and a 94cc Polini evo kit. I have the PHBG19 del and the PHBL25 del. When I ran the 19 on a stock engine, W/oil pump, I found that the oil pump feed line on the PHBG to be too large and it causes the line to split. I would run new oil lines when doing this carb swap as their old and brittle.

[245luigi]

Looks very similar based off my memory. I know the PHBG comes in several different models, I have the dell'orto PHBG 19 AS.

[LoveMyKymco]

AS is clamp style for the stock style intake kymco you bought it for thats the only difference.  It should of came with a package with extra jets and a needle. Mine came with a W0 and W7 needle. The W7 was installed and I quickly changed it to the 0 but then went with a W3.
These are wicked accurate carbs but take a little time to fine tune. Not a lot of people on here have had good experiences tuning them as theyre not the same as Keihin or mikunis. You will need to do some reading for fine tuning with it as the jet and tune scale isnt the same.
What do I know, I havent actually owned or used one and I just took pics of someone elses stuff I guess. I also guess someone else paid my credit card invoice and ordered it to my house for me. Crazy world.

[245luigi]

Do you think I can keep my stock throttle cable or should I install the one that came with it?

[LoveMyKymco]

On the Piaggio Hi Per 2 it came stock with a dellorto carb so I could have used the cable or the stock one. Ill return on the 6th next week and if you havent set it up I can check at the shop then. A lot of people widdle down the stock cable ends to fit into the dels usually rather than go buy a new one.
I know I had to on my first del swap when I bought the wrong cable. If you order a single wire cable and using it on a del or arreche make sure to order a del cable, not a generic one or it will be for Keihin/mikuni style carbs. The only reason you would order a single cable conversion is if youre deleting the oil pump. On mina style based engines ( like the like) if youre not spinning 12k+ you can leave the pump and just add a 1oz 2 stroke oil to the tank full.
Being as its not a 100% correct and true minarelli design engine ( your engine is tilted at a degree not completely horizontal like a real mina is) I wouldnt try to rev it past 12k anyways. Real minas and morinis can spin way past 14k. At the point of hitting 13k rpms your stock pump cant meter enough oil because its already at its max vacuum draw. Thats why you need to add some to the tank. Problem is it will gum up your carb so you need to clean it every year or run some Seafoam every so many miles. I rather clean it every 6 months than run seafoam but I dont mind dropping the float bowl. On the PHBL style carbs the float bowl is held on by one screw in the center. Those rock.
Im only giving you 100% first hand experiences here, no speculation or reading someone elses posts online and regurgitating it. 100% field experience.

[245luigi]

Glad you mentioned the oil pump, I completley forgot there was a Y connection in there with the cables. I have the stock keihn carb so looks like ill be whittling down the end. At what point should you be adding oil to the tank (im assuming on top of what the oil pump is outputting too) with stock motor or as soon as you go 70cc? Also if I start adding 1 oz per tank do I need to play with jetting? Thanks for all the info.

[LoveMyKymco]

Add oil after installing the big bore kit if you are going to be running it higher than stock rpm. Always upjet with any introduction of pre mix. If you add something that isnt fuel (2 stroke oil pre mix) into the same size orifice(jet) youre no longer getting the same amount of fuel to the cylinder.
The main reason for more oil is for the higher rpms you will see with the better porting from the big bore kit than what the stock pump is made for. It actually makes less power on the extra oil you add but better safe than sorry if youre going to retain the stock pump.
At a side note also, the size of the cylinder also dictates if you need to add oil to the mixture as the volume is effectively larger. Not just higher rpms but displacement as well. Even if you were to keep it at lower RPMs if the cylinder volume is 50% larger you obviously need to compensate.

[245luigi]

The bike has a hose running from the oil pump and branching into a "Y" with one leg going to the intake manifold and the other leg going to the stock carb. The new dell'orto does not have a connection for this hose. Is the proper way to handle this on install is by replacing this hose with an unbranched, straight hose from oil pump to the intake manifold?

[245luigi]

Bump. Its the oil pump outlet line. I have no idea why it runs to the stock carb (Keihn PB16). Just a single line to the intake, right behind the reed valves should do the trick, amirite?