Honda Motorcycles - FireBlades.org banner

1 - 12 of 12 Posts

·
Registered
Joined
·
28 Posts
Discussion Starter #1
Howdy All, I have a '93 900RR in standard trim and I recently fitted a BMC airfilter and had a dyno run which reported that I was getting 93nm torque and 117 hp at the back wheel. I was offered a really good deal on a full Kerker exhaust system and also a Dyno jet kit which I have had fitted. The bike was then tuned and dyno run again and now gives 90nm torque and 122 Hp. Is this the best I can expect?. Also there was a power dip between 4 and 6000 rpm which everyone thought the exhaust and jet kit would eliminate but it hasn't, is this normal?
Many thanks
Tim
 

·
Registered
Joined
·
240 Posts
I'd say that is a good increase from a full system and jet kit. You can always get the heads ported and polished, put in an overbore kit, get new cams, titanium valves........
 

·
Registered
Joined
·
28 Posts
Discussion Starter #4
Thanks I really appreciate the replies. I'm just disappointed as the bike feels worse now than before they put the jet kit in. After I had the exhaust fitted they didn't have time to tune and dyno run and the bike felt fantastic, especially above 6000 rpm. Now it definately feels like it's lost something and I'm considering going back to standard jets. What do you think should I rather get them to try tune it better or is standard jetting the way to go?
 

·
Registered
Joined
·
28 Posts
Discussion Starter #6
Dear Skater, thanks a lot I'll tell them to try that. What do you think about an advancer?
 

·
Registered
Joined
·
28 Posts
Discussion Starter #7
Thanks BlackBlade, I have a BMC filter and full Kerker free flow. They will just have to play with the jets.
 

·
Registered
Joined
·
62 Posts
+1. I've seen measured HP on early Blades to be 112-115, so 123 is pretty f-ing good.
:plus1: to the power, very healthy numbers. sorry it's not riding so nice but it's a common complaint after someone's messed with the jetting.

If you're going to do anything else to correct this I'd consider returning to standard jets and air filter. Many people start to have these kind of probs when they start messing about with the intake setup.

Unless your going the whole overbore etc. hog, which has to be done right and can be achieved cheaper and more reliably by just buying a newer bike, I'd say stick with stock intake and spend a small amount of cash on a good end can or find someone that really knows what they're doing to fix your current setup.

Personally I love these old blades but because of they're age there's usually enough going on with them to keep you occupied maintenance wise not to have to worry about jetting too. The stock jets are fixed and work fine with a stock filter spend money getting new jets and a carb overhaul or buy a newer carb from somewhere but keep it stock. Then any fecker can balance and tune them and any end can that's been tuned for the bike will give an extra couple of horsies right out of the box. If I were looking for another one I wouldn't touch a bike that's been rejetted.
 

·
Registered
Joined
·
62 Posts
sorry to rant - perhaps more inline with what you asked..

getting higher peak power is a cheap trick if it's at the expense of low and midrange which is where you spend most of your time if you're an average schmo - like most of us.

since you have a full exhaust system on there maybe there's some merit in tweaking those jets to get the most from it but if the bike felt nice with the new exhaust and stock jetting why go through the extra aggro?

Anyway if you do wanna stick with this, for your money you're looking for an overall higher and smoother curve throughout the rev range and little or no 5.5k dead spot (as I understand it this dead spot is tuned in by the manufacturer for no other reason than to get through emmissions control) often and aftermarket exhaust is enough to get rid of most of it. If that's not what you got then it's not right.

If your tuner achieves just that, even at the expense of a little peak power you'll still be ready to believe anything the dyno operator says and more importantly your ride will be massively improved. I'm not qualified to dis dynojet but those kits are expensive, a good tuner will probably have jets and settings lying around for all that and you needn't necessarily have to pay out for a "dynojet" branded selection.
 

·
Registered
Joined
·
28 Posts
Discussion Starter #11
Thanks Road_Rubber, I started the upgrade proccess when my air filter needed replacing and I went with a BMC. Everyone recommended that I upgrade my exhaust and I got a sweet deal on a full Kerker system meant for a Blade. But of course the bike needed to be tuned for the exhaust. Once again numerous people recommended I go with a jet kit as standard generally run lean. The bike goes in on Tuesday and I'll ask them to set the needles down one notch and see what happens.
 

·
Registered
Joined
·
62 Posts
Thanks Road_Rubber, I started the upgrade proccess when my air filter needed replacing and I went with a BMC. Everyone recommended that I upgrade my exhaust and I got a sweet deal on a full Kerker system meant for a Blade. But of course the bike needed to be tuned for the exhaust. Once again numerous people recommended I go with a jet kit as standard generally run lean. The bike goes in on Tuesday and I'll ask them to set the needles down one notch and see what happens.
No worries TnT. Good luck with that, I'm sure you'll get it sorted. Maybe see if you can have a chat to Kerker before Tuesday too. If you can get through to someone technical they should be able to tell you what jet/filter setups they tested it with. If the system was designed for the blade they should have some useful info. Fair enough to assume that a more freeflowing exhaust will lead to a lean condition but see if you can get that from the horses mouth.
 
1 - 12 of 12 Posts
Top