[Lukeb]

Hi all,
Just got my '95 750 ss back from a dyno tune after getting a dynojet kit stage 1 fitted. The bike also has a new k and n filter, snorkels removed from airbox lid and staintune slip-ons. New plugs and oil/filter and belts too

Sadly the figures were less than spectacular. I have a grand total of 59.5 hp. This is 1 hp more than prior the dynojet kit and filter

My question is, is this average for the 750 or is mine getting tired? It has 45 000km's on it. I really expected a bigger gain and a better looking graph

Any important or figures you guys have would be greatly appreciated

[sheepy]

Id be interested in this one!
I too have a dynojet fitted,albeit a 900ss,and used the appropriate jets in the kit.I too removed snorkels and vent pipes along with fitted race cans.

I now have 2 into 2 bespoke exhausts i made myself and thought it would upset the running but to be honest it hasnt affected it much at all.i do think the jets Dynojet reccomend may be a little on the large side tho !!

[1fast750ss]

Hi Luke,

I don't post much here, though I should being my track bike is a 750. I hope I can shed some light for you as to why no real gains.

1. Low Compression = low HP
2. Small Valves = doesn't breathe well
3. Small Cams = only good for the road, very flat
4. Really Bad Porting = get overworked fast, not fluid, too many bends.
5. Small Carbs = works only for stock engine, not for power.
6. Small Exhaust = Good for road TQ, not RPM able for good power gains.
7. Small Airbox = lack of ability to achieve proper inlet resonance for high RPM power(anything over 7K).
8. 5 speed = lack of acceleration due to too tall between gears. Makes the bike feel slower.

What this basically means is the the 750 from the beginning is really doomed for performance in it's basic state.

That being said, it can be a very formidable bike. You just have to approach it from a realistic strategy. Tis bike isn't going to win any power wars, but it is(or can be) very light(FWIW).

Another advantage to this bike is the TQ curve and subsequent layout of power, as to how it gets to the rear tire. Use this as your basis.

My '01 750S put 58HP to the rear wheel stock(with DP exhaust). That wasn't going to work(in my head) so I went out, unfortunately without a plan and proceeded to spend twice what I should have if I had a plan. I learn from my mistakes(and digress).

You should understand the bikes' shortcomings and attack those first. Look at the list I put and say: "what can I do to fix them?" Here's what you do, going cheapest to most expensive.

1. Airbox lid mod. Need to rejet, worth 1-2HP
2. HC pistons. Always adds HP, apprx 5-8HP. I personally went with the 795kit, awesome!
3. 800SS heads. Great mod! Better porting, bigger valves and cams(more lift), also have adjustable cams pulleys for better timing. Works with HC pistons and exhaust for apprx 15-18HP gains.
4. 900SS exhaust, modified to fit 750. Adds 5mm Dia for better flow to accent the higher comp and bigger valves/cams.
5. 6 speed from an 800ss. Cheap alternative to adding acceleration, better choice of gearing. Drops right in.
6. Bigger carbs. Your choice there, be it flatslides, etc., 38mm would be my suggestions unless you go big bore kit.

Most important thing is to drop weight of the bike as much as you gain HP. 3lb is equal to about 1HP gained. Concentrate on rotating mass. Find some 5 spoke wheels from a newer SS. They will drop about 4lbs total. I have 999 wheels on mine, so even lighter. Have the flywheel lightened/removed(on that model). It will still idle fine.

See what parts "really" do not need to be there, or can be trimmed. Eventually you will find the bike has shed some decent weight.

So create an end game, design a plan and execute it correctly. You will spend much less money in the long run and have your bike running exactly how you want it. Some of these mods will not work on their own, however there are steps you can take to keep the costs down. I hope this helps.

Just FWIW: Last time I dynoed mine, it was 86HP/64TQ rear wheel. I have since reported my heads with bigger valves, race cams, race guides, new seats(different cuts for better flow) and some freshening up. Expecting low 90'sHP and around mid to upper 60's TQ(still the same displacement, better efficiency)

[Lukeb]

Hi Brian,
Thx so much for your reply. It is very detailed and informative
Your bike sounds amazing and I'm sure you have invested some serious time and effort into it with great results.

I'm leaning towards turning my bike into a race-bike also as cosmetically, its very tired and not worth refreshing in my opinion

I do love the old girl and am constantly surprised at how well it drives if you keep the momentum up in the fat part of the mid-range.

I'll be asking some questions of you in the future re the upgrades I'll under-take for sure

Cheers

[1fast750ss]

Just to throw another bit of info in Luke, I am currently machining a set of adjustable triples for the SS. They will use the SBK triples I manufacture, with a modified stem to fit the SS.

This will recoup the loss of trail as I am running a set of offset bearings to lessen the rake by 1 degree.

The goal is a rake of 22.5*, while trail remains at approximately 97mm. Very fast turning yet stable. I just need to develop my weight bias correctly, since there is no water rad to add weight up front.