Dyno dilemas

[Robw]

Having gone to the Dyno day and got a disapointing 63 bhp for my Z1170 with Keihan carbs, obviously something is not quite right. I spoke to the chap and he showed me the dyno graph, it climbs quite rapidly and looks like a normal shape graph, but tops only 63 bhp.
At full chat black smoke was coming out of the exhausts and I have noticed it does use a bit of petrol.
He said that it seemed to be running really rich, looking at the plugs No 2 and 4 are very black, 3 and 1 look normal. Other comments from people watching said it sounded wooly.
It happily revved through the redline and acclerates really well on the road, with what seems enough power.
I have took of the head and the timing was correct and I could not see any problems with the bore. Although one bore did seem to have a lot of petrol in it.
I am aiming to fit the new head and take it to Seastars to be set up on the dyno, but want to make sure nothing else could be wrong before rebuild
Would excess fuel cause a power drop like this?
Cheers Rob

[hillbilly]

sounds like its not breathing well.

[Pigford]

Excess fuel will cause lack of gooooo. Also too much fuel will wash the bores and can cause bad wear

My 1075 Black Z1000 is gasflowed with RFS36's and dyno'd at 90 bhp

What ignition you running? Wot pipe?

[Robw]

Piggy, running standard ignition, but with a kerker pipe. Once it is sorted I will be fitting my gasflowed head. The plus side is that it seems to go like hell at the moment, when it runs at full power I might need wheely bars

Rob

[big green bus]

took my gpz1100 1170. 33 mikuni's to LEDAR years ago had 70 bhp after he finished with it, it had 125 bhp just on jetting and he did not alter that much. the mains were 130's, but i cannot remember what the needles were or set at as the carb's were nicked a week or so later

[Robw]

Bgb, thats really good news as I thought something had gone drastically wrong. That is an impressive increase just by jetting, so once it is built it will be going to Seastar to be fettled with.
Cheers Rob

[Rich]

I had 92 with 1075 kit, 29 s/bores and a slightly stifled 4 into 1 all the rest std.
Now has cams, full race pipe but no dyno sheet yet

Make sure your electrics are Ok, timing (valves and ignition), valve clearances all carbs set the same - then get it carbon analysed.

[Robw]

I have just got a head modified and built by Alan at Kipkawa, big valves, lumpy cam and gas flowed, so hopefully everything will be tickity boo when I fit it.
Rob