Engine mods?

Does anyone make any engine modifications? Such as pistons/ valves/ cams/ etc? Ive done some google searching and havent found anything. I figured you guys would be the ones to ask, thanks!

-Jared

 

Helps to know what bike you are trying to modify. You can check Web Cams, or Wiesco piston websites for help. For basic engine modification like balancing or headwork, you will have to look up your local engine builder.

Sean

 

One of the reasons you aren't finding anything, no matter which XJ you're working on, is that unless you're planning on going to the racetrack, there isn't much you can do to improve a stock XJ's performance. Properly tuned in stock trim these things (even the 550s) are rockets. As soon as you start messing you end up sacrificing somewhere for every gain elsewhere, in terms of rideability.

 

sorry guys, goofed on that one. Its a 1981 XJ750 seca.

 

I dont know if I agree with that. I agree that for a 750 the seca makes very good power. But a few simple mods while i have the engine apart, such as some lightweight valves, or slightly higher compression forged pistons could not hurt or effect rideability.

 

Bore the jugs 20 to 40 over, get weisco teflon coated pistons , and baby it for 1000 miles. giving it at least 3 oil changes. this works great on snowmobiles as well. someone here was modifying his ride by dumping the carbs and using a fuel injection system out of a 4 cylinder nissan/ honda? haven't heard of the final results of that one. maybe I 'll hunt that one down and see .

just put together a 1997 mxz 670 skidoo this way and it rocks like the wind. a damn site skunkier we have 2 skidoo wave runners we are doing this to as well

 

IMO a waste 'o time One can take the errr.. Large amounts of $$ Modding these Relics would require and simply add it the resale of your XJ to buy a faster models are Fine as is. No amount of lipstick is going to make a lot of difference.

 

And there's the best answer! Unless you want to do it so you'll have something 'different' or 'unique', don't waste the time or money. Every performance mod, like fitz said, usually results in some drawback. And anything that doesn't will cost you 5 times what its worth.

 

flash: i looked on the weisco site and it said they didnt have pistons for an XJ750.

And pistons/ valves are not only for some minor performance gains, but to have this bike for another 100k or so, cast pistons suck, sorry but they do, after a while they will self destruct. I allready have a XLH1200 that will smoke all your XJ's so im not looking to make a speed deamon

 

LOL someone asked me along time ago.. Ok its a classic bike, but what kind of lap times will it do. I answered back with a 1:34 at Willow Springs.. Smoke all of our XJ's??? Bring it on, sure someone on here can always go faster. Besides my Seca 550 has done a 1/4 mile time at 11.7 seconds at about 110 mph. Bring on the friendly competition

Sean

 

haha, thats damn fast for a 550. I built the engine in my sporty, it makes 90rwhp and about 80 rwtq. weighs about 450 wet. Race tech front suspension, progressive shocks out back 18" wheel with some dunlop GT501's on it. Id love to bring it on willow springs. And im sure there is someone on here with a bad a#$ XJ, i was just jokin
***Edited by Robert. Language please! Thanks!***

 

OOoooooh. Can i get in on this race with my TL? (I'll trailer it to the track with the XJ for reliability though! lol)

 

huh, i wasnt aware that as* was an offensive word. Is there a bunch of 8 year old kids running around on the XJ forum or are we all adults here? Ecxuse my ignorance im new.

 

golly gee schucks

 

According to the dictionary a#$ is a vulgar term, you might want to read up on it if you were unaware. Just a friendly reminder that this forum is for the general public's consumption (reads: lots of other folks raised differently) and I have my daughter sitting here with me once in a while. While you may not find certain words offensive, others do and I happen to be one of them. Save the potty language for the men's room or PMs. 'Nuf said.
In other news, I'd love to see your XLH1200! Got pics?

 

Hi Guys
So ... how do I get hold of a big bore kit or over size pistons for an 1983 XJ900 I'm playing with ??
I'm down under & havn't had any luck at all
Cheers Andrew

 

http://www.who-sells-it.com/r/yamaha-mo ... -kits.html

 

The '83 was 853 CC , the '84 and later were about 892 (?) CC.
I've wondered what it would take to make a true full litre bike from a Seca 900, or how big can you go.

A guy took a CBX - 6 from 1,050 CC all the way to 1,400 by machining a custom cylinder block and crank. A labor of love, for sure.

 

understood man. I dont have any pics of my sporty on this computer, but ill try to post some in the next few days.

 

:?: