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View Full Version : My suzuki doesn't rev.



Cruisin' Craig
30th April 2008, 23:12
Well actually is does, but not as high as I would have expected. Well not quite as high anyway.

I don't make a habit of ringing the nuts off my bikes, but I do it often enough to know that this is the first bike I've ever owned that won't reach it's redline.

In fact it seems to rev very happily until 10500 rpm, then sputters and surges and won't rev any higher. This isn't a huge problem as it is redlined at 11000 rpm.

I am curious to know whether this is because:

a) my bike isn't running the way it should and is being starved for fuel or air or something at high revs. or...

b) it's a bit of valve bounce setting in when it maxes out its revs, it's just the way the bike is, and all I need to do is be nice to my engine and not try to rev it higher.

Points to note:

a) My bike is a 1985 GSX-R750.
b) It's maximum power according Mr Internet is 100hp at 10,500 rpm. Coincidentally exactly the revs my bike will reach.
c) As far as I can tell my bike runs well right through the rev range until then.

What I'm hoping for here, is that someone will read this who has owned a bike like mine, and will tell me that their bike was like this too.

Anyone reckon they can answer my query????

munterk6
30th April 2008, 23:29
Yeah Ive got one the same, but mine goes to 11000rpm quite happily. The problem with yours could be any one of several variable, or a combination of a few. Compression test, electrical system test, fuel system test needed.
But if it runs ok in the useable rev range...dont worry bout it!!!:spanking:

Cruisin' Craig
30th April 2008, 23:42
Well, I was hoping to hear it was perfectly normal for the bike. :weep:

The thing is, how do I really know that it's running right through the rest of the rev range? It might be down on power all the way and I'd never know because I don't have a good one to compare it with.

Unfortunately, since I am no mechanic, if I test all of those things I could very quickly spend far more than the value of the bike.

I think I'll stick with your "don't worry about it" approach. :cool:

Wicked bike by the way. Gotta love those things.

F5 Dave
1st May 2008, 17:20
Could easily be one of several fairly cheap things. I'd clean the carbs out & check not any grit in there (suzi tanks often need sealing do a search), also check for a fuel filter, often when fitted they kink the fuel line if not careful.

Then airfilter & plugs could be next on the likely list, then coils which are another weak point on old GSXRs, some 2nd hand Honda ones might be a cheap fix. Measure plug caps too to see that they aren't duff (cheap $10 multimeter will be goo enough). Also good idea to check the bike isn't over charging with meter, but they aren't so bad for that compared with GSXs, but not immune.

Monsterbishi
2nd May 2008, 12:23
Or the tach could be reading wrong, and you're actually hitting the rev limiter?

crash harry
5th May 2008, 21:58
Try something - if it gets to the point where it won't rev any more and you back the throttle off a little, does that allow it to rev up to the limiter? If so it's likely to be a fuel delivery problem. Check your fuel filter isn't blocked and there are no kinks in the fuel hoses.

If that doesn't work it could be carbs or ignition. Or, as someone mentioned, a dicky tacho but that's unlikely.