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Stage one Performance Mods

Bubba Blue

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I’m new to the forum. I’m browsing and using “search” but not really coming across what I’m looking for

Can you refer me to a popular thread that talks common slip on, intake and most importantly proven carb rejetting for stage one?

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I don't thin that there would be one given thread on all that, but you should be able to find different opinions here and there. You'll need to tell us more about your bike and exactly what it is you want to do. If it's a first gen then post in the 1st gen forum, if it's a 2nd gen then in the 2nd gen forum.

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I assume you are talking about re jetting the carbs and modifying the intake and exhaust for "better" performance?

The problem with doing that kind of thing with these bikes is getting things to run smooth across the throttle range is darn near impossible. The CV carbs are vey particular when it comes to air flow and the air box on the XVZ and XJ Yamahas, and probably a whole lot of other Japanese bikes, is designed to supply the air evenly at the needed volume and cfm. Start monkeying around with it and you will get dead spots and uneven intake due to turbulence at different speeds. 

There were volumes of threads on the xjbikes forum about this. people adding velocity stacks with pods, up jetting and running open drags. Some went so far as to add adjustable intake butterfly valves and manually adjusting them. All had the same story to tell. It just doesn't work well.

You might get marginally "better", I.e., faster off the line or slightly higher top end by up jetting and running a high flow air cleaner at the expense of fuel economy, but these bikes already have pretty darn good performance for as big and heavy as they are.

Just one guy's opinion, YMMV.


ETA: You might want to talk to the guys at Ignitech about a performance programmed CDI. They are very knowledgeable about their products and our bikes. When I went with their module on my '83, they were very helpful via email.


Edited by luvmy40
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