CB450 K0 dynojet and why it doesn't need a five speed trans

Phil-UK · Post by **Phil-UK** » Wed Sep 15, 2010 10:41 am

Hi Jensen

Watched the video but can't see a link to the dyno charts.
Are the CB72 ones in the same place ?

Have fun at Assen,

Phil

versuspop · Post by **versuspop** » Wed Sep 15, 2010 10:45 am

'71 k4

jensen wrote:Hi,

Yes, you're so right.
What kind of 450 do you have ?

Jensen

jensen · Post by **jensen** » Wed Sep 15, 2010 12:01 pm

Hi,

Phil, you have to log in if you want to see the dynojet stuff, it an image without a link.
Saturday it will be dry and sunny, good for me, a pity you cannot be there,

A k4, a bike where all the engineerings errors are fixed, nice bike and a good rider with the disk front brake, any pictures ?

Jensen

Phil-UK · Post by **Phil-UK** » Thu Sep 16, 2010 2:07 am

Doh !

versuspop · Post by **versuspop** » Thu Sep 16, 2010 3:32 pm

Here are a few...
http://s278.photobucket.com/albums/kk87 ... pop/CB450/

jensen wrote:Hi,

Phil, you have to log in if you want to see the dynojet stuff, it an image without a link.
Saturday it will be dry and sunny, good for me, a pity you cannot be there,

A k4, a bike where all the engineerings errors are fixed, nice bike and a good rider with the disk front brake, any pictures ?

Jensen

brewsky · Post by **brewsky** » Sun Sep 19, 2010 10:07 am

Here's an interesting version listed on ebay, and the price looks good....... at least for now.
Tempting!
http://cgi.ebay.com/ebaymotors/1975-Hon ... 255d7520b1

jensen · Post by **jensen** » Thu Sep 30, 2010 3:53 am

Hi,

Brewsky, could you withstand the temptation ?, did you buy it ?
Versuspop, it's a nice bike, how many miles on the odometer ?

Sorry to see that there are no dyno runs of a standard bomber available. It makes my work a little harder to interpret as general behavior of the bomber engine, but it's all i can do.

In the meantime I have set the needles of the carbs one position higher.

Theoretically, the mixture in the 3000 to 5000 rpm is o.k, but if it's a little richer in that erea, the torque might be more linear. On the road it feels like it is better,smoother and more powerful but soon I will put the bike on the stand again to look at the following things :

Because the bike was very low miles, and still within the breaking in period, I like to see the effect on the engine of the 1000 miles I did put on it last months. On the road it feels stronger above 7000 rpm. It also pulls easier to the red line, but all that could me my brains and ears fouling myself because of wishful thinking and getting used to higher rpm's.

The bike was idling irregularly from day one, the gas analyzers showed a huge fluctuation in the amount of unburned mixture. I decided not to look into it, and make 1000 miles first, to see what happens. Now, after 1000 miles, the bike does a perfect idling. You only can hear by the slowly increasing and decreasing idling that the valves of the floats are opening and closing. the difference in idling rpm is no more that 250 rpm, but still much more then my CB72's (the cb72 float bowl is much bigger and thus resulting in a smoother idling behavior).

The effect of setting the needles one position higher increases the amount of fuel in the mixture, therefor chancing the way it behaves between 2000 and 6000 rpm, I like to know what exactly is going on in that area, and hopefully discover a positive effect on the torque. Like I mentioned, it feels better, but that is all subjective since I got used to the bike over the period I rode it.

I like to have a comparison between the first dyno runs and the ones I will have within a few weeks. It gives me something to work on in winter if necessary.

Jensen