What's the diffrence between a gs 450 20 kw and 31 kw?

[laurent314]

Here is my problem. I broke a rod on my suzuki gs 450 1983 and it is a 31kw release. I found a motor GS450 1981 but only 20 kilowatts. What's the difference between the two engines?

Thank you for your answers

Ps: sorry for my english, i am from belgium ;-)

[boingk]

Not sure. Perhaps one engine is a four valve engine (square cam covers) and the other is a two valve engine (round cam covers)?

- boingk

[Mekanix]

Difference is who measured it :P

You will often find different measurements for the same engine with no differences.

There were updates from 83 on, Mostly in the clutch though and I don't think anything relating to the cylinders or head.

You could be looking at the measurements from a restricted engine. In that case it could have restrictors on the intake or exhaust for licensing or emission purposes that limit its power output. But remove that and its the same engine.

The 8 valve was only a 400 but stock it put out more than the 450.

[GregT]

The clue to the answer is in Laurent's address - Belgium...

Several continental countries, Switzerland and Germany come to mind, had and still have HP restrictions on different licencing classes.
I'm not sure how the restriction is done in this case but it's probably a restriction on the carb slide lift or VERY restrictive mufflers.

Either way, I'm pretty sure there's no mechanical difference between the motors.

[Agemax]

the 81 engine was only produced with a 20kw engine (27bhp). 82 and 83 had the beefier 31kw (42bhp) motor