XT VS SR

[pancho]

 For my information, which engine parts for XT500 are different from SR 500?
 Are both model conrods the same?
 I know the SR head has a bigger inlet port dia. and bigger inlet valve, and a kick start indicator window, any other differences?
 Are the barrells identical?
 Oil pumps?
 Ignition?
 Gear ratios?

 I have seen a photo of an engine that has been modified with the head bolt (near the spark plug) modified into a through bolt to the crankcase.
 
 I had previously contemplated such a mod but feared difficulty working around differing stress loading factors with temperature variations etc.
  Does any one have details of this mod?  I did lift the barrel off its flange at a Nepean practice day a few years ago!
 

 Cheers pancho.

[GMC]

They are all pretty much the same.
It was only the inlet valve that was bigger on some models.
Rods, Exhaust valve, Cam shaft were all the same

Part # = 583-11651-00-00
Part Description = ROD,CONNECTING

Part # = 583-12121-00-00
Part Description = VALVE,EXHAUST

Part # = 1E6-12171-00-00
Part Description = SHAFT,CAM - Replacement Number = 583-12171-01-00 *


Model Count = 16
SR500E 1978 500 SR500 Street
SR500F 1979 500 SR500 Street
SR500G 1980 500 SR500 Street
SR500H 1981 500 SR500 Street
TT500C 1976 500 TT500 Off-Road
TT500D 1977 500 TT500 Off-Road
TT500F 1979 500 TT500 Off-Road
TT500G 1980 500 TT500 Off-Road
TT500H 1981 500 TT500 Off-Road
XT500C 1976 500 XT500 Dual Purpose
XT500D 1977 500 XT500 Dual Purpose
XT500E 1978 500 XT500 Dual Purpose
XT500E-205001 1978 500 XT500 Dual Purpose
XT500F 1979 500 XT500 Dual Purpose
XT500G 1980 500 XT500 Dual Purpose
XT500H 1981 500 XT500 Dual Purpose


They all have the same gear set except for the extra 78 XT which has a different 3rd gear part No.

The last 2 model XT's had CDI, all other XT's & TT's had points..
Part # = 583-81621-50-00
Part Description = CONTACT BREAKER ASSEMBLY
Model Count = 10
TT500C 1976 500 TT500 Off-Road
TT500D 1977 500 TT500 Off-Road
TT500F 1979 500 TT500 Off-Road
TT500G 1980 500 TT500 Off-Road
TT500H 1981 500 TT500 Off-Road
XT500C 1976 500 XT500 Dual Purpose
XT500D 1977 500 XT500 Dual Purpose
XT500E 1978 500 XT500 Dual Purpose
XT500E-205001 1978 500 XT500 Dual Purpose
XT500F 1979 500 XT500 Dual Purpose

[GMC]

Inlet valve - small

Part # = 583-12111-00-00
Part Description = VALVE,INTAKE
Model Count = 7
TT500C 1976 500 TT500 Off-Road
TT500D 1977 500 TT500 Off-Road
XT500C 1976 500 XT500 Dual Purpose
XT500D 1977 500 XT500 Dual Purpose
XT500E 1978 500 XT500 Dual Purpose
XT500E-205001 1978 500 XT500 Dual Purpose
XT500F 1979 500 XT500 Dual Purpose


Inlet valve - large
These have 2 part No's, early and late model I guess but it looks like they are interchangable

Part # = 2J2-12111-00-00
Part Description = VALVE,INTAKE - Replacement Number = 2J2-12111-01-00 *
Model Count = 4
SR500E 1978 500 SR500 Street
SR500F 1979 500 SR500 Street
SR500G 1980 500 SR500 Street
TT500F 1979 500 TT500 Off-Road


Part # = 2J2-12111-01-00
Part Description = VALVE,INTAKE
Model Count = 66
SR500H 1981 500 SR500 Street
TT500G 1980 500 TT500 Off-Road
TT500H 1981 500 TT500 Off-Road
XT500G 1980 500 XT500 Dual Purpose
XT500H 1981 500 XT500 Dual Purpose

XV1000L 1984 1000 XV1000 VIRAGO 1000 Street
XV1000LC 1984 1000 XV1000 VIRAGO 1000 (Cal) Street
XV1000N 1985 1000 XV1000 VIRAGO 1000 Street
XV1000NC 1985 1000 XV1000 VIRAGO 1000 (Cal) Street
XV1100A 1990 1100 XV1100 VIRAGO 1100 Street
XV1100AC 1990 1100 XV1100 VIRAGO 1100 (Cal) Street
XV1100B 1991 1100 XV1100 VIRAGO 1100 Street
XV1100BC 1991 1100 XV1100 VIRAGO 1100 (Cal) Street
XV1100D 1992 1100 XV1100 VIRAGO 1100 Street
XV1100DC 1992 1100 XV1100 VIRAGO 1100 (Cal) Street
XV1100E 1993 1100 XV1100 VIRAGO 1100 Street
XV1100EC 1993 1100 XV1100 VIRAGO 1100 (Cal) Street
XV1100F 1994 1100 XV1100 VIRAGO 1100 Street
XV1100FC 1994 1100 XV1100 VIRAGO 1100 (Cal) Street
XV1100G 1995 1100 XV1100 VIRAGO 1100 Street
XV1100GC 1995 1100 XV1100 VIRAGO 1100 (Cal) Street
XV1100H 1996 1100 XV1100 VIRAGO 1100 Street
XV1100HC 1996 1100 XV1100 VIRAGO 1100 (Cal) Street
XV1100J 1997 1100 XV1100 VIRAGO 1100 Street
XV1100JC 1997 1100 XV1100 VIRAGO 1100 (Cal) Street
XV1100K 1998 1100 XV1100 VIRAGO 1100 Street
XV1100KC 1998 1100 XV1100 VIRAGO 1100 (Cal) Street
XV1100K-L 1998 1100 XV1100K-L VIRAGO 1100 Street
XV1100L 1999 1100 XV1100 VIRAGO 1100 Street
XV1100LC 1999 1100 XV1100 VIRAGO 1100 (Cal) Street
XV1100S 1986 1100 XV1100 VIRAGO 1100 Street
XV1100SC 1986 1100 XV1100 VIRAGO 1100 (Cal) Street
XV1100SH 1996 1100 XV1100S VIRAGO 1100 SPECIAL Street
XV1100SHC 1996 1100 XV1100S VIRAGO 1100 SPECIAL (Cal) Street
XV1100SJ 1997 1100 XV1100S VIRAGO 1100 SPECIAL Street
XV1100SJC 1997 1100 XV1100S VIRAGO 1100 SPECIAL (Cal) Street
XV1100SK 1998 1100 XV1100S VIRAGO 1100 SPECIAL Street
XV1100SKC 1998 1100 XV1100S VIRAGO 1100 SPECIAL (Cal) Street
XV1100SL 1999 1100 XV1100S VIRAGO 1100 SPECIAL Street
XV1100T 1987 1100 XV1100 VIRAGO 1100 Street
XV1100TC 1987 1100 XV1100 VIRAGO 1100 (Cal) Street
XV1100U 1988 1100 XV1100 VIRAGO 1100 Street
XV1100UC 1988 1100 XV1100 VIRAGO 1100 (Cal) Street
XV1100W 1989 1100 XV1100 VIRAGO 1100 Street
XV1100WC 1989 1100 XV1100 VIRAGO 1100 (Cal) Street
XV920J 1982 920 XV920 Street
XV920K 1983 920 XV920 Street
XV920MK 1983 920 XV920M Midnight Virago Street
XV920RH 1981 920 XV920R Virago Street
XV920RJ 1982 920 XV920R Virago Street
XVS1100AMC 2000 1100 XVS1100A V STAR 1100 CLASSIC (Cal) Cruiser
XVS1100AN 2001 1100 XVS1100A V STAR 1100 CLASSIC Cruiser
XVS1100ANC 2001 1100 XVS1100A V STAR 1100 CLASSIC (Cal) Cruiser
XVS1100APC 2002 1100 XVS1100A V STAR 1100 CLASSIC (Cal) Cruiser
XVS1100LC 1999 1100 XVS1100 V STAR 1100 (Cal) Cruiser
XVS1100MC 2000 1100 XVS1100 V STAR 1100 CUSTOM (Cal) Cruiser
XVS1100N 2001 1100 XVS1100 V STAR 1100 CUSTOM Cruiser
XVS1100NC 2001 1100 XVS1100 V STAR 1100 CUSTOM (Cal) Cruiser
XVS1100PC 2002 1100 XVS1100 V STAR 1100 CUSTOM (Cal) Cruiser
XVS11AM-B 2000 1100 XVS1100A V STAR 1100 CLASSIC Cruiser
XVS11AP 2002 1100 XVS1100A V STAR 1100 CLASSIC Cruiser
XVS11AR 2003 1100 XVS1100A V STAR 1100 CLASSIC Cruiser
XVS11L 1999 1100 XVS1100A V STAR 1100 CLASSIC Cruiser
XVS11M-B 2000 1100 XVS1100A V STAR 1100 CLASSIC Cruiser
XVS11P 2002 1100 XVS1100A V STAR 1100 CLASSIC Cruiser
XVS11R 2003 1100 XVS1100A V STAR 1100 CLASSIC Cruiser

[Simo63]

The SR motor has 12 volt CDI vs the XT/TT motor that is 6 volt points.

[Colin Jay]

  I know the SR head has a bigger inlet port dia. and bigger inlet valve, and a kick start indicator window, any other differences?
 Are the barrells identical?
 Oil pumps?
 Ignition?
 Gear ratios?

The SR500 head has larger fins than the early XT/TT head but later XT/TT's have the same head as the SR.

The kickstart indicator window is on all XT/TT500's except the original 1976 "C" models.

The cylinder barrels are the same, I have mixed and matched between the various XT's, TT's and SR's that I own without any problems.

Ther were two different oil pumps fitted. The early XT and TT oil pumps have a slightly different body (3 screws), but use the same rotor sets as the SR engines which have a 5 screw body. Later XT/TT's use the same 5 screw oil pump.

The RH end of the SR gear selector drum runs on a needle bearing while the early XT/TT gear selector drum runs directly in the crankcase, this changed on the post 1978 XT/TT 500 when most of the SR improvements were carried over to the XT and TT models.

There was a difference between the gear selector shafts, between the early  XT/TT and the SR, the early XT/TT has a splinded shaft that allowed the selector mechanism to be removered from the shaft while the SR and later XT/TT's has the selector mechanism welded onto the shaft. The ealy selector shafts have not been available for many years and the SR part is the supersesion for it.

The gearbox ratios are the same, and as GMC has said there are a few different part numbers. The part numbers for the counter shafts are different between the XT/TT and the SR but you can fit a XT/TT gear box assy into a SR and visa versa.


The spacer behind the countershaft sprocket is different between the XT/TT and the SR, to allow for the different chain sizes, XT/TT 520, SR 530.

These are the main differences n the engines that I can remember of the top of my head, there are probably a few other minor differences.

CJ

[pancho]

 Thanks for all that, I will copy and keep it all.
 
Does anyone know the details of the mod I saw in a pic (on the forum somewhere I think it was) where the head bolt near the plug has been extended through to the crankcase on the flywheel side. I would like to do that as there are no actual through bolts.
 
I realise this could be tricky because of differing tensions on the stud during temperature changes also the head clamping pressure needs to be higher probably than the through bolt tension. Perhaps a stepped stud was used?
 cheers pancho.