Manfred's TR1. Discussion Boards

Old TR1 Discussion Boards (read only) >> Discussion Board 2004 >> Engine rebuild

Message started by Keith Jenkins(Guest) on 29.12.04 at 00:40:00

Title: Engine rebuild
Post by Keith Jenkins(Guest) on 29.12.04 at 00:40:00

I ride an '81 XV750 Midnight Special. I would like to know if the pistons, barrells and heads off a XV1000, will fit onto the 750 engine?  Has anyone out there tried it?  I have a spare '83 TR1, and the old 750 is due for a major engine overhaul, so I thought wouldn't it be nice if I had 1000cc's between my legs : D

Title: Engine rebuild
Post by Hartmut(Guest) on 28.12.04 at 17:58:00

maybe the parts may fit but the starter´s torque isn´t strong enough for both cylinders with 1000 ccm! The starter motor of TR1 has another mechanic as the XV 750 starter.

Title: Engine rebuild
Post by Keith Jenkins(Guest) on 29.12.04 at 11:10:00

Thanks heaps Hartmut for your interest, I agree, the starter motor would need to be upgraded, but for me, that is not an issue. I was hoping someone out there might have already done the hard yards in working out what can be swapped over, before I start my rebuild. Cheers buddy,  Keith.  P.S.  MERRY CHRISTMAS  : D

Title: Engine rebuild
Post by Bob Jenneson(Guest) on 04.02.05 at 00:46:00

Hi Keith.....Bob here. I have an XV920RH that I will be upgrading to 980cc (1000). To do this I will need to have my crank case bored out to accept the larger cylinders. In addition to this you will need to obtain some 920 0r 980 con rods as the piston pin bore is 2mm larger for the 920 and 980 pistons. Your cylinder heads will likely have to be changed as the combustion chamber and valves will be too small. You would wind up with an engine that could not breath properly and would have too much compression to burn pump gas. Don't worry about the starter as there is an upgraded 4 brush model available which is much better than the stock unit.

Title: Engine rebuild
Post by Keith Jenkins(Guest) on 09.03.05 at 22:05:00

Thanks for your help Bob,the bottom line is it just can't be done.  I picked up an XV1000, pulled the engine down, and sized things up, comparing everything to a dismantled 750 engine I have. I found your comment on the upgraded 4 brush starter motor interesting. I have not heard of this upgrade. Could you tell me where these starters are available from ?  Thanks for your reply and Cheers, Keith :-D

Title: Engine rebuild
Post by Bob Jenneson(Guest) on 18.03.05 at 04:38:00

Hi Keith.....Bob here. I will call the parts shop tomorrow and get a part# for the upgraded starter. I put one on my 920RH and it spins the engine over like I've never heard it before. I paid $385.00 CDN ehich is about $275.00 US. Its worth every penny. I also installed an absorbed acid battery (made by Deka). This battery is highly aclaimed by that unfortunate group who ride Harley Davidsons.

Title: Engine rebuild
Post by Keith Jenkins(Guest) on 22.03.05 at 22:01:00

G'day Bob, you bloody bewdy mate :-)    I enjoyed your "tongue in cheek" comment about that unfortunate group :-D  I have seen those batteries and yes, they are the ducks guts. Cheers buddy

Title: Engine rebuild
Post by gavin(Guest) on 26.03.05 at 22:02:00

has anybody tried fitting a newer xv750 engine in place of an old se unit, have ahd an se for a lot of years sprayed in oil languishing in a garage with a very tired engine but a good rebuilt chassis, would love to get round to sorting it out some day