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Replacing a 1982 XV750 engine with a 1986 XV700

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Replacing a 1982 XV750 engine with a 1986 XV700

PostAuthor: SiCkSTi04 » Mon Feb 11, 2019 11:24 am

Hi everyone,

I picked up a second virago for free over the weekend. It’s a stock 82 XV750 with an oil cooler that was sitting.

The issue I face right now is the previous owner snap the nut that screws on the crankshaft while trying to free up the engine (ouch!). I have a complete spare engine from a 1986 XV700SS. My question is will the 750 heads, pistons and jugs swap over to the 700 bottom end without any issues or modifying? I don’t think I can ‘simply’ swap the entire 700 with all the 750 electrical components in place.

The plan is to swap over a good working bottom in with gen2 starter and re-use the 82 engine mounts with 750 heads with every stock electrical component from the 82 in place.

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Last edited by SiCkSTi04 on Mon Feb 11, 2019 12:38 pm, edited 1 time in total.
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Re: Replacing a 1982 XV750 engine with a 1986 XV700

PostAuthor: Jake » Mon Feb 11, 2019 12:03 pm

Lets look at something before swapping. The nut you say the PO snapped, are you sure it’s not the cover over the crank bolt ?

That would be number 11 on this diagram, it is aluminum and only covers the bolt, commonly snapped and cheap to replace.

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Re: Replacing a 1982 XV750 engine with a 1986 XV700

PostAuthor: SiCkSTi04 » Mon Feb 11, 2019 12:44 pm

Jake wrote:Lets look at something before swapping. The nut you say the PO snapped, are you sure it’s not the cover over the crank bolt ?

That would be number 11 on this diagram, it is aluminum and only covers the bolt, commonly snapped and cheap to replace.



Hey Jake,

It's definitely not the access cover bolt (17mm), its the crank nut behind that. The nut snapped from the crank, it's a 19mm.
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Re: Replacing a 1982 XV750 engine with a 1986 XV700

PostAuthor: Jake » Mon Feb 11, 2019 12:58 pm

You should be able to replace the 750 with the 700 easily enough. You’ll need the engine mounts off of the 750, maybe the stator and pickups too, but can’t recall off hand.
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Replacing a 1982 XV750 engine with a 1986 XV700

PostAuthor: SiCkSTi04 » Mon Feb 11, 2019 4:16 pm

Jake wrote:You should be able to replace the 750 with the 700 easily enough. You’ll need the engine mounts off of the 750, maybe the stator and pickups too, but can’t recall off hand.


Yep, I have the mounts. From what I research/read, both early engines use dual pickups but I'll need to confirm both pigtails have matching plugs and wires to be sure its plug and play. Pretty sure i would need to use the newer foot pegs too because of the wider engine covers too. Hope someone else can chime in that has had similar success.
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Re: Replacing a 1982 XV750 engine with a 1986 XV700

PostAuthor: bstig60 » Mon Feb 11, 2019 5:58 pm

The engine from the 700 should bolt right into the early 750 frame. Both engines are dual PU. There are a few minor wiring differences, but nothing catastrophic. Use the google search on this forum for wiring diagrams for both engines... IMHO, I would change the complete engine as long as your 700 engine is good.
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Replacing a 1982 XV750 engine with a 1986 XV700

PostAuthor: SiCkSTi04 » Tue Feb 12, 2019 7:24 pm

bstig60 wrote:The engine from the 700 should bolt right into the early 750 frame. Both engines are dual PU. There are a few minor wiring differences, but nothing catastrophic. Use the google search on this forum for wiring diagrams for both engines... IMHO, I would change the complete engine as long as your 700 engine is good.



I might just do that... Plan to tear down and inspect the 750 over the weekend and go from there. If it checks out fine worst case I might be able to pickup just a crankshaft from a local ebayer and rebuild it.
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