The Triumph 650cc Unit Overhaul Manual
The Bonnie Ref
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Bonnie At the Castle
Page -2- Triumph 650 Unit Overhaul Manual
NOTE: Most bolt and nut sizes are Whitworth (B.S.F. interchangeable) except where U.S. sizes are gradually being introduced.
Unit construction engines start with DU101, 1963 models.
| Machine | Model | Change |
| 1964 DU5825 | T120 | 1-19/32" intake valve (E4**03) and 1-7/16" exh. valve (E2904) instead of 1-1/2" inlet (E3310) and 1-11/32 exhaust (E3927) |
| 1965 DU13375 | All | Oil release valve changed to blind cap (no oil pressure indicator) |
| DU13375- DU24874 | All | Crankshaft located by drive side (before DU13375 and after DU24874 crankshaft located by timing side - see applicable parts manuals and CD411) |
| DU19895- DU25337 | All | Oil bleed holes in connecting rods |
| 1966 DU24875 | All | New tappet guide block and push rod tube seals Pressure lubricated exhaust tappets, (E6329 std. radius, E5490 "R" radius) metering jet dowel E6800/3 or E6348 in timing cover. Light flywheel E6327. Roller drive side main bearing instead of ball bearing. |
| T120 | Change from E3001/3002 to E4221/E4222 valve springs. Change to "R" tappets (1-1/8" radius) E3059R and E6490. 9:1 pistons (CP206) instead of 8:1 (CP200) | |
| DU31119 approx | T120/R T120TT only | Sports exhaust camshaft E4855 replaced by racing camshaft E5047. |
| 1967 DU44394 | All | 9:1 pistons - E6868 in place of CP206 or CP200. |
| TR6 | 1-19/32" intake valve and 1-7/16" exhaust valve instead of 1-1/2" intake and 1-11/32 exhaust. Change to "R" tappets (1-1/6" radius) E3059R and E6480. Sports exhaust camshaft E4855 replaced by racing camshaft E5047. | |
| DU47006 | T120 | Change to heavy-duty connecting rods 1. Check on all models by measuring across front or back of rod shank at a point 1" below bottom of pin hole - old type measures .550" and new heavy duty type measure .605". CAUTION: See note on assembly sheet. |
| DU48144 | All | Change to unified thread transmission (gearbox) mainshaft. |
| DU51771 | All | 160-degree ignition cam #54419124. |
| DU63043 | All | "Timed" lubrication exhaust tappets (3/32" flat) E8801 ("R" radius) and E8895 (Std. radius) - change back to plain timing cover dowel T989. |
| DU63241 | All | O-ring under shoulder of tappet guide blocks. |