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HP numbers
- Thread starter Jfraser06
- Start date
How many guys have the tools or access to measure horsepower? Harbor Freight?
Scott
Scott
Is that a dial caliper thing or a graduated cylinder thing?
In all seriousness though, is there another bike on the road that more exemplifies the idea of "More than the numbers would suggest" than the XS650? I could be way off base here, but I'd doubt it. When I ride mine, or look at mine, or tinker with mine, it's all about the way it makes me feel. My point being I would expect the number of guys who have taken their bikes to a dyno to be very small, even among the guys who have done big bore kits.
People dyno tune bikes all the time! Maybe not xs650’s but a lot of people dyno bikes!
Before reading on these were unscientific tests, done on different days, weather conditions, the dyno was not calibrated and I expect slightly optimistic.
We did the before and after test more out of curiosity and for carb tuning than anything else.
Test 1:
A 750 with 10:1 compression standard head VM 36mm carbs tuned exhaust and Webb 59A cam. Best pull 58 HP.
Test 2:
A full on race 750cc motor. Best pull 77 HP.
So from a 750cc motor with a milder cam and stock head you will hopefully be in the mid 50’s, a full blown race 750 70 plus HP.
The key to making reasonably good power is the head.
I have read that these old girls will hold together to about 73HP above that they start to become grenades.
If you want to build an XS the modification guide from 650 Central is a good place to start.
In the UK Smed Speed would be worth talking to,
We did the before and after test more out of curiosity and for carb tuning than anything else.
Test 1:
A 750 with 10:1 compression standard head VM 36mm carbs tuned exhaust and Webb 59A cam. Best pull 58 HP.
Test 2:
A full on race 750cc motor. Best pull 77 HP.
So from a 750cc motor with a milder cam and stock head you will hopefully be in the mid 50’s, a full blown race 750 70 plus HP.
The key to making reasonably good power is the head.
I have read that these old girls will hold together to about 73HP above that they start to become grenades.
If you want to build an XS the modification guide from 650 Central is a good place to start.
In the UK Smed Speed would be worth talking to,
