Yamaha xj600s Diversion Help needed

First of all I want to greet you, because I am new to the forum and to the bike. I got it a few days ago and for some reason I love it. I have a few questions that I would like to ask. On the documents of the bike it says that it is 37 kw which is about 50 hp. I know that this engine is 61hp and there is a version with 67 hp. My bike is imported from Germany and I know there might be some restrictions for the lower hp. The engine is 4BRA I think. The thing I want is to at least get the stock hp that are 61 or 67 from the other version of the xj 600. Mine is xj600s diversion 1992
I don't know if this is possible or not. I am new to this community. I also have a slight problem. When I start the bike, let it warm up, the first 10-15 minutes are minutes of hesitation - the bike doesn't rev good in the mid, either you have to give it all the gas or it doesn't rev good in the middle. I think it is a gas problem. The carburators have been ultrasonic cleaned, the tank is also cleaned and there is a fuel filter on the fuel line.
The bike has been sitting for a long time and maybe it needs to be ridden a few hours to get in "shape".
Well this is from me for now, now let me hear your opinions

 

Update :
I fixed the hesitation. It was caused by a lot of things that were not as they should be on the carburators, air filter, fuel lines and etc.
Now my only concern is if there is a way to make it go faster, maybe tune the carbs with richer settings. I don't know

 

it appears there were 2 versions available for that year in Germany ,one 20kw the other 37 kw. the earlier pre diversions were a lot more powerfull 73hp. with twin discs up front and an oil cooler,--- like the one in my avatar. you could put your bikes frame number into this web site to check its output
https://www.bike-parts-yam.com/yama...00S+(37KW)+600+1992&val_pays_v3=ALL+COUNTRIES
cheers
stu

 

Thank you mine is 37 kw. Do you think it is possible to make it 60-70 hp and if yes how?

 

Downshift and hammer the throttle.
Oh, you meant how to get more power? ----- get a 900

 

No I mean get the stock hp out of this engine which is from what I read 67 hp and there is a version with 73hp.

 

the 73hp engine is a completely different design and not easily interchanged. I think it would be easier (and cheaper )to change the engine for the more powerfull one , theres loads on ebay, or at least in u.k. there is.
stu

 

Okay then I want to make it 67 hp which this engine makes stock. How?

 

What is the difference between 37KW and 67 HP? How many HP is 37KW? I'm kind of lost with the usage of two different terms.

To me, it's like saying "I want a faster car, so what kind of truck should I buy?"

 

1 hp = 746 watts so
37ooowatts divided by 746 watts = 49.6hp
I don't know where the op gets the 67hp from, that would be 50kw
I can only find 20kw and 37kw versions, 20kw = 27hp
stu

 

http://www.motorcyclespecs.co.za/model/yamaha/yamaha_xj600s_98.htm

There you go. 45KW is what I want to achieve. This is the same bike as mine

 

1. How many miles are on the bike?
2. Are all the valve clearances within spec?
3. At the carburetors been thoroughly cleaned, totally rebuilt, float level set, and running sent?
4. have you put it on a Dyno and run it through all the gears and RPM range to find your current peak horsepower?

 

37kw = around 50hp at the rear wheel.
61 hp would be at the crank.
that's what you've got
stu

 

Probably yes. Well I won't be doing anything to the bike then.
Maybe an exhaust mod would be cool to do, but I have no experience there and I don't want to destroy my stock exhausts. If there is a guide somewhere where you can make them sound better I would be greatful to the guy that shows me it

 

What do you mean by 'sound better'?

Quieter? leave them stock
mods? Why---want to lose more power?
Louder? Why?want to sound like a Harley? It won't.