Author Topic: T120 Pre-unit ignition & float problem.  (Read 3592 times)

Offline Scriberman

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T120 Pre-unit ignition & float problem.
« on: May 13, 2008, 04:24:07 AM »
 Hello people.
Background: I usally ride and fix modern Jap(please keep reading) off road bikes but have a freinds T120 in my garage.
Problem 1: L/H carb keept flooding, new needle and seat, still same. ??? Polished float where it meets needle, same, ??? Filed a bit off cover return where the float pivot hits (slight whitness mark) cover, same ???.
 Refitted float with 'FRONT' marking facing inwards, problem solved ;D Why ???

Problem 2: Now no spark? removed kill switch wire,same ???. Unscrewed points cover (mag ing) and turned engine, mag not turning ???
I can turn the points by hand about a quarter turn.
Sometimes when turning the engine the mag will catch and turn about half a turn. ???

 So before I rip into it (timing case off, mag off) is this a common problem/most lightly thing to be broken :(

Please tell me a nut has come undone on the mag gear???  ;D

 Thanks in advance.

Offline thunderbird

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Re: T120 Pre-unit ignition & float problem.
« Reply #1 on: May 22, 2008, 08:38:23 AM »
hi i used to have a pre unit bonnie if i remember correctly the magneto drive gear is fibre, maybe it has stripped some teeth , it is a taper fit to the magneto it could be slipping on the taper if the bolt has come loose you will need to remove the timeing cover to check.Regards Steve

Offline Big_Frank

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Re: T120 Pre-unit ignition & float problem.
« Reply #2 on: May 22, 2008, 02:42:48 PM »
I had the self same problem, mine was down to the fibre mag drive. Now and again when the bike kicked back on starting it wrecked the fibre gear which was always at an inoppertune time and also quite expensive so I fitted a Dural gear, supplied by Unity Equipe (UNA 189) for £31 and this seemed to alleviate the problem. I agree that it might be a taper problem and worth investigating before shelling out any readies.
Frank
"Pleased to meet you, hope you guessed my name"