1981 xj650 engine?

Greeting's,
I'm new to motorcycles, but I am mechanically incline. I'm an aircraft mechanic and done my share work on cars. I bought a 1981 yahama xj650 for 200$. The motor is blown so I decided to pick up a project and buy it. So I have the engine out and I'm looking for a new engine. I've noticed online for sale that there an engine xj650 seca turbo with black covers and then there the one I have that is a regular xj650 engine with grey covers. My question is how different are the engines? What engines am I able to use on my bike?
Thank you

 

Can you define 'blown' ? If its only top end (head pistons etc) it might be easier to refresh these. Like as not with any replacement engine you will have to partially strip to check valve clearances, de-coke etc..

 

I apologize I should of been more specific. There is a hole on the bottom end coming from cylinder #2.

 

it is just a different set of carbs for the turbo setup. beefier internals.
you could use www.yamahapartsnation.com to compare cams use old part number when it is listed

this link has the info you need its a slow loader but talks about motor swaps
http://www.xjbikes.com/forums/threads/the-information-overload-hour.27544/

 

Usually, factory turbos have lower compression and different cam profiles. They often also add squirters (oil jets that hit the bottoms of the pistons) to cool the pistons.

In the case of the XJ650s , NA is 9.2:1, and turbo is 8.2:1 for compression.

Using a turbo engine without the turbo will definitely result in disappointing performance compared to a stock NA engine.

 

pretty sure a 750 goes in there with very minor mods

 

Got a picture ?

 

A 750 Maxim engine is a direct swap.

Is the damage in the cylinder or in the engine case?

 

What would you pay for engine with 6200 miles on it?

 

Attach are some picture of the engine.

I have been looking online and I just wanted to get the best deal and the correct engine. Good to know that the 750 maxim engine is a direct swap.

To be completely honest with you I dont really know how much they go for. I have been seeing that the engines are running from 150-350 without shipping. Do you have one? If so and if its a good deal I would be interested

 

Nice hole. Slap on some JB weld and run it

I would do a teardown first. You'll want to inspect the internals anyway to see what can be sold to recoup some of the costs. If the spiny-round bits are in good order you might be able to find a good set of cases to swap (you'll want to confirm the bearing sizes in the replacement case if you go that route. New bearings can be spendy and diffficult to find).

If you're really, really lucky that hole might have been caused by something other than a con rod letting loose.

 

does the exhaust attach the same with the collector vs the crossover pipe? i need to spend more time under my bike

 

The 750 uses a collecter instead of the crossover that the 650 has.

 

The 650/750 "yics" system, is that only in the carburetors? My bike doesn't have the yics system and wondering if I can use a 650/750 yics engine on my bike. From looking on eBay there's only one engine for sale just like mine.

 

The YICS system is part of the cylinders and head. You can swap in a YICS engine wihout needing to do anything special. The jetting on the YICS engines was slightly leaner, but you can run your carbs as-is.

 

Here's the swap info you need:

http://xjbikes.com/forums/threads/alternative-engines-for-82-maxim-750.30457/

 

Xj900 pre-diversion is a straight swop. Don't get turbo. Too much hassle with pressurised carbs and leaking turbo.

 

I got a hold of a xj650 engine. Thank you everyone for the help.

 

Ok
If anyone is looking for a low mile great runner engine PM Me

 

Uh.... NOT.

 

Oh it'll fit Dave. You just need a grinder and a welder, and the requsite skills to use them.

 

I know that.

No, its NOT

And here's why not...... Lol
Not to mention the rest of the things that need to be accommodated

 

Uh. Yes. That's what I have on my xj now

 

In a Maxim 650 frame? Pics please.

 

Physically, the engine fits in the space, albeit a tight fit, but there are things that need to be done..... It's not just plug-n-play

 

I have a 1981 xj650 that has a rattle in the gears which would be cheeper replaceing the motor or the gears?

 

Diagnosing the problem first will be cheaper than diving in and assuming that something needs to be replaced. Start a thread and describe the problem as thoroughly as you can.

 

Any motor will fit with some creativity

 

From Len:

* when putting an XJ900 engine into a XJ650 Maxim, Midnight Maxim, or RJ Seca frame, please observe the following changes:

- although there are anecdotal stories of this swap being accomplished, we've never seen or verified the completion of such a project. There may be some engineering challenges involved due to the greater height of the XJ900 engines, as well as other issues.

Besides that, the same guidelines as generally outlined in the XJ700 engine swap should be observed.

 

For all the swap info, go to the information overload hour, scroll down to the section on Engine Swaps

 

Go for it.