Supersport Build = Loss of 8 HP

In the winter of '09-'10 I had an SS build done by a "reputable" builder but the result was a loss of 8 HP (111 hp before and 103 hp after). The build cost me $1300 and included the following:

•Remove cylinder head
•Measure squish (piston to head clearance)
•Clean combustion chamber
•Disassemble cylinder head
•Inspect/prep valves
•Inspect valve seats
•Check valve spring pressures
•Set cam journal clearance
•Machine gasket surface (angle or straight mill)
•Reassemble head and install
•Slot cam sprockets or install cam adaptors
•Check and adjust valve clearances to spec
•Degree cams to spec

Both dyno measurements were performed on the same dyno by the same tech (not the guy who did the build, nor associated to in any way). The bike is an '07 600RR w/ PCIII, BMC, and Akra full stainless exhaust. After the 2nd dyno was performed (Spring '10) I took the bike back to the builder who did a leak-down test and said that the motor was not losing any pressure, but couldn't really offer me any explanation or resolution, other than to suggest trying race gas instead of pump. I'm more likely to question the quality of the build vs the dyno results, the bike definitely does not feel like it has more power than prior to the build.

The motor runs fine, in fact I rode all last year without any issues, just down on power. Is there something simple that could explain the loss power? Any recommendations on engine builders within a couple of hours of Cbus, OH? Should I be concerned that the motor might be "sick" at this point?

 

was the PC3 tuned after the build? could just be a mapping issue

 

Yes, that was part of reason I had the 2nd dyno performed.

 

I know people who swear by 35motorsports, but I have no experience with them myself.

 

Tuned properly?

Anything else change on the bike between dyno runs, other than engine work?

 

is that price with the motor in the bike or just handing him the motor?

 

I think the purpose was not to put the shop on blast dude

 

How's the power band look? Any odd spikes on the new chart from the old?

 

Who did you go to?

 

That was the whole bike with him removing the motor. The bike came back immaculate and he did a whole lot of "value-add" things that I didn't ask for and that he didn't charge for (cleaning/greasing bearings, performing some additional safety wiring tasks that I hadn't addressed adequately myself). The price was fair in my mind for the services I had requested, but the results were less than what I had expected.

But that ship has sailed honestly, it's a year later and I'm not going to ask that builder to resolve the issue. He had an opportunity to fix it but didn't/couldn't, and then the season got rolling and I didn't have time to take it back. I'd just as soon find a someone else to look it over, and who is more familiar with Hondas.

 

I'd prefer not to say in public. He's a nice guy that I think just got in over his head with a brand of motorcycle he wasn't familiar with. I wish he could've offered me more to get this resolved, but I should have pressed him more for results at the time.

It doesn't really matter at this point who did the build. I really just want to know if I should be concerned that this thing is going to grenade itself and if there's a chance that someone else more knowledgeable would be able to get it sorted inexpensively.

 

2 best builders I can think of would be 35 motorsports or Pegram Racing..

 

Supersport build with no valve job, just 'inspection?' Unusual.

Does your bike have the jumper mod?

Do you know how much was removed from the head?

 

Valve job was optional, I didn't do it.

I think the "jumper mod" is for Ninjas, not aware of one for the CBR.

Will have to check on how much was shaved off the head, that info is at home.

 

Hey Rick get out of my head! did you get my check?

 

Same dyno, same conditions? (fuel, temp etc) Just saying that dyno's are relative.

 

Same dyno, same dyno tech, same weather conditions, almost the exact same day of the year.

 

I saw you post something about "he said it isn't leaking..", but have you actually done leak down and compression tests? Leak down will show if it's past the vavles or rings/pistons, and will hear if there is leak from cyl to cyl.

 

He did leak down, yes. Said it was fine. Can't confirm if a compression test was done.

If there was a leak between cyclinders wouldn't I be having some major problems other than a loss of power?

 

Did you use same size/brand rear tire?

Here is a difference between Dunlop D211GP 190/55 vs Metzeler Z6 180/55