Xs motor swap, 78 into an 80?

[Abate guy]

Hi guys, been peepin these forums for a while and finally have a need to post a question. My 80' XS11 Special has 90k on her and the motor is just started to make a helluva racket from the top end. Im thinkin of swappin it out instead of a rebuild. A friend of mine has a spare motor from a 78 XS with only 20k on it he's willing to part with. Will the 78' work in my 80'?
She's been down almost a week and its KILLIN me!!

[Ken Talbot]

If it just started making a racket all of a sudden, try adjusting the cam chain tensioner. It could be that your adjuster has simply come loose and needs to be reset. You need to remove the left side engine case and set the timing indicator to the "C" mark while turning in the direction of the arrow. Loosen the locknut, then listen carefully as you looosen the adjusting screw. You may hear a slight noise as the tensioner spring pushed the adjuster in. Retighten the adjusting screw and locknut, start it up, and see if the noise goes away. Be careful not to overtighten either the adjuster or the locknut or you maay strip the threads in the soft aluminum housing. If this turns out to be your problem, it will be a lot easier than swapping motors!

[rover]

It will bolt right in. It might be a good idea to use your carbs, TCI and coils, I know the 81's are different, but don't know if the 80's are or not

[Abate guy]

Thanx for the reply Ken, I have already removed the tank, carbs, breather box, exhaust etc. I was runnin 120 mph + with a few brothers from my club when this happened. Shes been burnin about a quart of oil ervery 6 weeks or so. I topped her off just a few weeks ago and the night she started making noise, I got her home and she was 1 3/4 quart low!! Im thinkin she got too hot and lost a ring or something. The noise is comming from the top of the right side though I cannot tell if it from the jugs or the head.

[Abate guy]

Thanx rover. Good advice. My buddy said the carbs that are on the 78' motor are all black. Would those be from a Midnight Special?

[rover]

If the carbs are all black, most likely from a Mid Spec. If your carbs worked well, use them. Go with what you know. Carbs on these beasts are very finicky, so go with the ones you know, if they are good.

[TopCatGr58]

Hey there Abate Guy,

Like Rover said, if your 80 carbs were working well, keep them, but ALSO Accept the 78's, good for some spare parts when/if needed!! You won't have those extra vent hoses to worry about keeping your 80 carbs. IF those donor carbs are black, they could be from a MN special, but not a 78, they didn't make it that year!!

The 80's had those special break off bolts that held the timing plate in place, but not sure if it used the newer ignition module, the 4R series vs. the 2H7 series, so like Ratbyk said, use the module(TCI) from the 78 bike.

You'll probably want to get new exhaust header gaskets, and might as well do a good cleaning of all the electrical contacts/plugs that you have to undue while you're there.
You might want to check the charging of the 78 once it's in there to be sure it's stator is working, but you'll have a spare from your 80 if it's not! Also do a cam chain adjustment, clutch adjustment, oil change, new plugs, etc., as well.

And if it's not been run in a while, re-read the tips on what to do to bring an engine that's been sitting back to life!?
Hope you get back to riding soon!
T.C.

[pgg]

A clacking top end after running 8000 revs in 5th and using heaps of oil afterwards? Sounds pretty much a stuffed piston or rings. First priority - a compression test.

[Abate guy]

Hey Rover, thanx for the input. I've had no problems with my carbs and plan to use them like you say.

TopCat,Thanx bro, I have all new header gaskets all ready for the new install. The main reason I decided to swap as opposed to a rebuild is that not only do I have lots of noise from a motor that has 90K+, but the second gear slip is beginning to rear its ugly head and if I can get a 20K motor with a carb bank for 300 bones Im a happy guy.

I havent swapped a motor in a XS before but I have some good friends in my club that are old school Yamaha boys that will help me in the swap.

PGG, Im with you on the piston ring deal. Pretty sure thats the problem but as I said, that coupled with the second gear trouble, I think I'm better off just swappin with a better motor.

[Abate guy]

Oh, and by the way you guys are a cool bunch of cats!! Ya know your **** and your advice is much appriciated!!! If you ever come to Michigan, Let me know, Me and the fellas will make sure your well taken care of!!

[noeleo]

Motor Swap

Abate guy, If you would take pictures and post them on this forum, it really would help us new guys. Also, if they are for sale, I need a set of black carbs for my 80 Midnight. Please contact meat this address: noeleo@indco.net Thanks