No top end speed

Silly questions = sillly answers. :silly:

if you want to cruise at 70 mph at 3000 rpm buy a car or a Harley. The reason bikes use as much fuel as a small car despite being a less than a quarter of the weight is because they have:

1) loads more aerodynamic drag -even on a modern sports bike or fully raired Goldwing . Cars have less drag then a bike generally.

2)wild cam timing tuned for top end power from a small displacement motor equals wasteful valve overlap

3) Primitive old school carbs, if in doubt (correctly) set a bit rich. No EFI knock sensors here.

These jap four bikes put out big power for little cc's, the secret is they rev higher. The redline is at 9 -10k...

With a 4-1and pods it sounds loud i know, but criusing at 6k all day is what these are designed for. Remember there is no metal/metal contacton any surfaces...everything 'floats' on oil -apart from on a cold start.

There are guys here riding daily for decades on these old motors, these are dangerous toys but don't be scared to trash them - once fully warmed up and on the right roads.

come back in a week and tell me it won't pull over 100 mph and we'll talk more.

Like ED said let some one that know's and work's on these old bike's look it it.
As for rpm's these motor's make their power ABOVE 6000 rpm's I was out for a ride earlier
and stopped to turn my rev limiter down a 1000 rpm to 9500 rpm's.

Thanks for all the reply's. From the left. The third carb was flooding (or leaking bad ) So after changing the gearing on it. ( It did not have proper ratio fitted. ) I took all the carbs apart and cleaned them. Put a new clutch adjuster inside left case where front sprocket is and set gaps correctly on spark plugs. After a bit of tinkering with the fuel / air mix. It now goes as it should. 75-80 is all I have done on it so far but will pull more than that. I changed the gearing from what was on it ( 2.54 ratio ) to 2.36. O.E being 2.46 ratio.
Now all I have to do is sort the cam chain rattle out when cold.