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21 engine into an 18?


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buntz

 
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21 engine into an 18?

Mon Mar 23, 2009 6:23 pm » Post: #1 » Download Post

hi all whats involved in getting a 21 engine running in an mc18r2j?
will my carbs and electrical connections work?
cheers buntz
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Andy
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Mon Mar 23, 2009 6:24 pm » Post: #2 » Download Post

Engine swaps between models has been covered a thousand times. Please use the search.
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buntz

 
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Mon Mar 23, 2009 7:37 pm » Post: #3 » Download Post

ok been searching for over an hour have'nt found anything on electrical compatibilty, i'm about to buy an engine so any advice much appreciated.
thanks.
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StephenRC45
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Mon Mar 23, 2009 7:44 pm » Post: #4 » Download Post

'21 motor into an '18 is easy.

The '21 has a GPS which also acts as a neutral switch on the '21. You need to wire this into the '18 harness as you will otherwise have no neutral light.

You will need to either swap all your pick ups from the MC18 to the MC21 as yours is a R2J or make sure that the '21 motor comes complete with fly wheel and pick ups. They differ in size so can't be swaped between those two models.
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buntz

 
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Mon Mar 23, 2009 7:55 pm » Post: #5 » Download Post

thanks stephen, will the gps affect anything other than neutral light ( de-restriction or wire splice issues) and can my carbs go straight on?
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StephenRC45
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Mon Mar 23, 2009 7:58 pm » Post: #6 » Download Post

GPS wont affect anything as long as you find the neutral wire. Thats the only one you have to tap into.

The '18 carbs will go right on and fit the '21 manifolds.

'21 motors don't make as much stomp as '18 motors though but if you're '18's dead it's better than than not riding.
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buntz

 
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Mon Mar 23, 2009 8:17 pm » Post: #7 » Download Post

my 18 barrells are perfcect condition and i have brand new wiseco single rings, would this redress the defecit? also i know the fuelling of my carbs and these barrels was safe, would i be better off using my top end if time permits?
anglesey this sunday, gonna be damp and my vj21 is VERY peaky, much rather be on the 18.
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StephenRC45
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Mon Mar 23, 2009 8:32 pm » Post: #8 » Download Post

The '18 barrels will help as their porting is better than a '21's. However the cases and crank are also better in a stock '18 over a stock '21 so you will never fully convert one.

Red, stock MC21 with stock pipes, moded air box and wire splice.

Blue, stock MC18 with stock pipes, moded air box and wire splice.


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geezagillard
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Sun Apr 19, 2009 4:49 am » Post: #9 » Download Post

Buntz
what are the single ring wisecos you are using? Can you supply a part no and/or let us know if you had to modify anything to get them working?
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