I'm rebuilding two Hurricanes ('89 & '90) and I'm experiencing the same issue with both of them. They both idle fine and once the get above 4k or 5k the throttle is fine and acts as it should. The problem is that, even after warmed up, the revs drop and the bike almost stalls when, from idle, I open the throttle med to quick. If I slowly open the throttle then the revs increase as they're supposed to. Anything faster than a slow roll on and I can hear the air sucking into the carbs (with tank & airbox off) and the bike almost dies before recovering and eventually catching up with the throttle position. I'm new to working on carbs, but I'm trying very much to learn all that I can about them and working on the bikes in general so any advice is helpful and a detailed walk through is the best I could ask for. Also, my assumption is that the carbs on the '90 are at stock settings and the others have been fiddled with but still seem to work just fine aside from this issue. Also, I'm in Denver, so I'm wondering if altitude has anything to do with this? Any ideas? Thanks all!

 

Have you tried this with the airbox on? It will make a difference with the increased airflow as it will lean out the mixture with the airbox off. Have you cleaned the carbs? Are there air leaks at the boots between the carbs and engine?

 

Yep, dumb enough as it was, all it took was tossing the airbox back on to fix the problem on the stock rebuild bike. The '89, which is going the streetfighter route, got better, but is woefully underpowered compared to the '90 and I'm hoping it's just a carb tuning issue. The only differences that I'm aware of between the two is that the '90 has a yosh pipe on it and its carbs are still at stock settings, while the '89 carbs have been fiddled with and the pipe is actually one of the pipes off of an '05 ZX-10R. The pipe's not enough to make up for the difference in power between the two bikes though currently.

Thanks for the, what should've been a no brainer, advice! d'oh!

 

I've been working on 50cc two strokes lately and am learning all about simple carbs and how airflow affects engine operation.

 

I'm jump'n in the deep end with the Hurricane carbs since I've never worked with carbs before and I'm just learning everything as I go. It's starting to look like I might have to rebuild the carbs in the streetfighter as it's still hesitating a little on a throttle burst from idle. I adjusted the pilot screws like honda said in the shop manual, but the manual says to turn each carb in by half turns until the idle drops 50 rpms (which I'm pretty much just listening for at this point) and then go one full turn out when the rpms drop. Idle dropped on carb #2 & 1, but not at all on 3 & 4, even if the screws were all the way in. I've got lots of learn'n to do!

 

ive had the same problem with my 94 cane. i fightered it out and im pretty much learning as go also. as for the throttle lag i had the vsame thing going on for weeks( pulled my hair almost completely out) lol try shiming your needfles on the carbs with a washer, the same size as the stock washer already on there. and see if it helps you. worked wonders for me thanks to sprock and the boys.