Big Bore Kit - Injector Required?

[u33db]

Hello,

Its been 5 years since i last owned a PCX125 but next week my new one should arrive.

This time i am keen to fit a big bore kit.

I will likely go with the Malossi 170cc kit, which includes a FI controller as described here;

https://www.malossistore.com/en/gb/alum ... c12515-M-P

I would imagine this cylinder is very similar to the Takegawa 170 kit which Maddiedog used on his conversion detailed on this forum. With his conversion he used a large injector instead of a FI controller to up the fuelling to a safe level so i have a question;

- What is better and safer for controlling the fuelling - using a FI controller or skipping that and just fitting a large injector?

I have read the stock injector is already near its limits so would rather err on the side of caution.

Ideally i'd just buy the full Yumiashi kit but there seems to be a question mark around their customer service, especially as they are abroad so that puts me off. On the otherhand i have used Malossi parts many times before and they have UK suppliers so i am more confident buying from them.

Opinions appreciated

[waspmike]

Damn. I thought I contributed I must have closed the page before the upload was complete.

You need to discover what size injector you have. It is written on the side. Likely an H or 5A or...

INJECTOR NAMES & FLOW RATES FOR KEIHIN B-TYPE INJECTORS:
• A INJECTOR      (6-HOLES / 90CC FLOW RATE) LINK
• VDT INJECTOR  (6-HOLES / 90CC FLOW RATE)
• 5D T INJECTOR (6-HOLES / 90CC FLOW RATE) MY BIKE STOCK SHORT
• NDJ INJECTOR  (6-HOLES / 90CC FLOW RATE)
• 5VJ INJECTOR (6-HOLES / 110CC FLOW RATE)
• 5H T INJECTOR (6-HOLES / 115CC FLOW RATE) LINK
• 5F T INJECTOR (6-HOLES / 120CC FLOW RATE)  This one.
• F INJECTOR      (6-HOLES / 120CC FLOW RATE) LI NK
• VF T INJECTOR (6-HOLES / 120CC FLOW RATE)
• H INJECTOR (6-HOLES / 140CC FLOW RATE) LINK
• 5J T INJECTOR (8-HOLES / 145CC FLOW RATE)
• VHT INJECTOR (6-HOLES / 145CC FLOW RATE) LINK
• 5A INJECTOR (DOUBLE SPRAY PATTERN / 160CC FLOW RATE) LINK
• 5LT INJECTOR (6-HOLES / 170CC FLOW RATE)
• NLJ INJECTOR (6-HOLES / 170CC FLOW RATE) LINK
• 5VJ INJECTOR (6-HOLES / 170CC FLOW RATE)
• 5ED INJECTOR (8-HOLES / 170CC FLOW RATE) LINK
• C INJECTOR (8-HOLES / 175CC FLOW RATE) 
• NNJ INJECTOR (10-HOLES / 235CC FLOW RATE) LINK
• 5NJ INJECTOR (10-HOLES / 235CC FLOW RATE)
• 58J INJECTOR (10-HOLES / 280CC FLOW RATE) 

Then you chose one a questimated amount more. My 110cc honda runs a 90cc one, a 5D. When increasing to 120-ish cc I will use a 120cc one as that is what I could find conveniently. maybe a bit large I don't know. I will check the plug colour just like I would when putting bigger jets in a carburettor. The bike has an oxygen sensor so below 6000 rpm may modulate the mixture anyway.
Yuminash has some recommendations if you click on individual injectors on their site. Then your next challenge is where to source an injector.