? on xs500 engine

[Scorpio1963]

I have an opportunity to buy one of these engines that runs,has carbs filters fairly cheap and localy.So my? would would it fit in an xs400 frame without much major modifications.Its the dohc engine but it doesn't look much different than the engines on the xs400.Also does this engine produce more horses than our 400`s cause when I looked up the specs on the bike it said top speed was only 82mph.Im thinking this is because of either the trans mission or the gear ratio that was used on this bike.
Any thoughts and or input appreciated,thanks in advance.

 

[Specdog]

Ah the infamous XS500 engine. If you get one, make sure it is from the last years of production in 1976 to 1978. The early engine known as TX500 from 1973 and '74 were pretty bad engines. It had what Yamaha called Omni Phase Balancer to make the engine smooth, but what happened is the balancer, in time, would actually go out of balance and hammer the engine instead. The engine also had overheating problems and the four valve head would commonly crack between the valves. The TX500 series was an embarrassment for Yamaha and caused recalls. By the way, the TX750 was even worse, but that's another story. The later model XS was an improvement but it's miserable history was too much to overcome and the model never sold well. Yamaha was determined to get it right and replaced the XS500 mid range line with our XS360 in 1976 and bumped up to 400cc later. The XS360/400 has a reputation as a very good motor. Yamaha was sure to get it right this time.
OK getting to your question about mounting one in our frame, the first thing I think of is the top engine mount that attaches to the 400 head cover. The 500 does not use that mount so it would likely have to be cut off to make room. The three mounts the 500 uses are roughly the same as your '81 but you will likely have to fabricate new mounting plates. Keep in mind the 1981 and '82 400 Specials don't use the top rear mount, so non is fitted to the frame.

 

[Scorpio1963]

The engine is a 78 so that's a good thing.Also could my electronic ignition be fitted to take the place of the points?Im also assuming if the engine doesn't have the original exhaust headers either something would have to be fabricated for those.Im pretty sure our xs400 pipes wont work unless proven otherwise?Also another idea I had for a project for this engine would be to buy some kind of roller frame to fit it in.

 

[xschris]

Not even worth it Why not a xs650 Oh that's right we have gone down this road before

 

[bcware]

Why do you need a new engine anyway? Did yours break?

 

[Scorpio1963]

I don't need a new engine its something I would consider getting for a project bike.

 

[Specdog]

I have a real soft spot for these bikes, despite what I've said about them. Cosmetically they are quite stunning. It's pretty easy to ride and restore an XS400/650 but it is an accomplishment to do the same with this lemon. I always give great praise to anyone who restores these unloved TX's.

 

[bcware]

I think you should definitely buy the engine and make your own custom motorcycle. It should be pretty easy with all the experience you have. I say go for it. It'll be awesome and very unique.

 

[Scorpio1963]

BC I don't know to take your comment as being sarcastic or what but yeah It would be a challenge and something unique to play around with.Id say with all the time I have on my hands I could probably complete the project within a matter of 2-3 years which is hardly nothing lol

 

[Scorpio1963]

Heres a pic of the xs500 engine the seller is asking $175. for it.So if I bought nobody has answered the question about if the electronic ignition from an xs400 can be retrofitted onto it?Or would I`d be better leaving the points in?

 

[xschris]

Ignition will not work Different motor different timing Just like a dohc xs400 ignition will not work on a sohc xs400.

 

[Scorpio1963]

Thanx Chris does this fire on the 360* crank shaft?Im realy think of buying it,I know where can I can get a titled roller frame that's a Yamaha xs650.It would be an interesting project.

 

[Specdog]

The TX/XS500 has a 180 degree crank.

 

[xschris]

If you can get a xs650 frame with title I would get that and find a xs650 engine and forget about the xs500

 

[Lou Ranger]

Scorpio, just 71 miles from the middle of the Bluewater bridge there rests: http://kitchener.kijiji.ca/c-cars-v...cessories-Yamaha-550-maxim-W0QQAdIdZ555195296

If the frame has a title it might hold the old 500 twin - or, maybe the 550 4 could eventually work.
The Forum should organize a relay among S. Ont. members and see if we can get this to you. A little gas money and a tray of "double/doubles" might do the trick!

 

[Scorpio1963]

@ xsChris I just seen a 650 engine not long ago but the seller is asking much more than xs500 engine.I have also seen xs750 maxium frames with bad engines all which would make good canidates for this project if I were to take it on.Of course Im not getting much support from my Mrs on this so I`ll see.

 

[xschris]

Good luck

 

[Scorpio1963]

Im probably going to leave this one alone,I know I realy don't have the time to commit myself to it.Im too much an outdoors a person and I don't want waste riding time during the warmer months.At the very least I couldn't do anything with a project like this till next winter anyways.I have a good acquaintance from my local autozone that's wanting a bike project maybe I`ll see if hes interested.

 

[Tombo]

That is a sound choice. Even the 400 has relatively low parts availability, the tx models are even harder and potentially more heart breaking too boot. Get yourself a 650. Been holding out for the right project to find me, that's the bike I yearn to get into more than most others. Love the idea of a 360 motor.

 

[Scorpio1963]

Im not sure my next bike if there is one would even be a Yamaha,I like Suzuki`s and Honda for jap bikes a lot.I like the twin cylinder engine 2 less carbs to tune and sync.I have realy got to know my bike the last couple of years I`d have hard time letting go of it.