I have a 98' blade
When it start up it starts first time but there is a serious problem.

I can ref it up to about 6000rpm and then I keep the throttle steady.
It then keeps on going up and down between 2000rpm and 6000rpm without me even moving the throttle. So it it's kind of revving up and down by it self with me just keeping the throttle open.(its very freaky seeing the bike revving up and down by itself) Keep in mind that all the time I'm still just keeping the throttle in the position where it would normally be running at 6000rpm.
I thought diaphrames on the carbs but they all seem ok.

The thing is when I got the bike I just started it and never revved it high. Then I stripped the carbs and cleaned them. So I don't know if it was doing this before I stripped the carbs(I didn't split them though). (maybe I messed up something)

Any ideas ?

 

[sm=icon_rofl.gif]Did you try new plugs? LOL

 

Vacum leak?

 

You'll have to let us know what you find, when you pull the carbs back apart. Make sure all the diaphrams are seated correctly, and all the springs are in place.

 

I've got another 2nd hand set of plugs that came out of my 600 with the last service.I'll first try them and if it doesn't work I'll strip the carbs.
Dont think it's anything series like valves

 

sync your carbs
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yeah sync your carbs dude, seems like the carbs are fighting against each other in cycles

 

So I checked everything you guys mentioned. The diaphragms are fine and I changed the spark plugs but I still doesn't work. I checked the butterflies on the carbs (visually) and they seem to open more or less at the same rate when you pull the cable so if the sync is out, it's very little. It also seems very complicated to sync them cause there isn't vacume connections on all the inlet pipes If I ref the bike slides open together at the same width.

What I did see is when you ref the bike and it starts hunting, the slides shudder up and down maybe this means something (all of them at the same rate)?

PS. The bike only does this when you ref it and not when it idles

 

Hi gerharddvs

I have done some reading around on the net about your problem and what problems other people are having, and almost all of them have got the same conclusion. Check your rubber seals on your carbs, which is on your float diaphram cover. There might be a slit in the rubber somewhere that is causing air to leak into the diaphram section as it moves. Check all of your vacuum fittings that they are all secure, and check that your carbs are seated properly on your intake manifold. Since this is only happening at high revs and not low revs, it mostly points to a vacuum leak as the pressure increases in the carbs.

Once you have found the vacuum leak (if that is the problem), you might have a little jumpy idle, syncing your carbs will be your next move.

 

So today I got some nerve together and had another look at my blade.
I tried something and discovered something actually by accident.
I had the tank of and filled the carbs with gas using a bottle. When there was no more gas running into the carbs, I removed the pipe from the bottle and blew into it to check if the floats were closing. I then started the engine and it was still doing that thing of only reffing up to 6000rpm. I decided to blow into the gas pipe going to the carbs. Suddenly I could redline the bike a couple of times(slides opening all the way so nothing wrong with diaphragms). It then started backfiring and went back to the way it was. I then filled up the carbs with gas again and repeated the test with the same result.

My conclusion was that it aether wasn't getting enough gas or it was sakking in air somewhere.
Once again I took of the carbs and cleaned them cleaned all the jets and the float levels. I checked the main jets and they are all 120 like the book says.I checked the rubbers where the carbs connect to the engine but nothing. I put everything together again but the bike is still doing the same. With the same result when I blow on the pipe.

I give up. Please help. At least now I know it isn't the CDI...Could it be something with the valves?