ZX7R Dyno run mk2

[AndyDRZ]

In October last year, I took my ZX7R to a dyno because it was running badly. It was diagnosed low compression.

Rather than rebuild the engine, I got a cheap one off of ebay (i know, i know) and fitted that....

It still runs as badly as before!

So, it's back at a (different) dyno and getting tested today...

Any thoughts on the diagnosis this time? I'm guessing rejetting will fix it.

[Riknos]

I voted Electrical, because sods law it would be electrical and you didn't need the new engine :P

[Hooli]

did the new engine come with carbs etc? if not id blame them as they are the normal fault on bikes as far as im aware. otherwise crap spark for some reason.

how did they diagnose low compression on a dyno? to do a compression test you take a plug out & screw in a gauge.

[AndyDRZ]

Yeah, new engine came with carbs...

Compression test was followed by leakdown test that indicated leaking through the exhaust valves.

[Hooli]

be odd to get the same fault, unless its a known problem with those engines?
any idea how long the 'new' engine was stood before you got it? modern petrols gum up a lot quicker than they used too. could just the carbs that came with it are gungy as hell.

[AndyDRZ]

Apparently it's richer than Bill Gates.