Topic: Dyno tuning the cb750A

[nixon]

Hi

I'm looking to do some tuning and dyno work on the auto. wondering if that's not recommended or anything to be mindful of?

Appreciate any input!

[DohcBikes]

It really depends on what your intention is. I have some questions if you are willing to answer:

1. Do you race?

2. Is it running well?

a. If not, and you are comfortable with it, have you attempted to tune it?

b. If so, what are you looking to gain?

3. Do you have any mods?

4. Are you just curious about hp? If so that's fine, lots of people are.

5. Engine, trans, anything making any noise that isn't normal?

6. Is it shifting perfectly?

7. Are you aware that tire manufacturers will not warranty their tires after a motorcycle has been run on a dyno?

8. Is there a dyno operator with a proven record in your area? Lots of dyno guys these days are very very bad tuners.

The answers to those questions will help you get a little closer to determining whether it is a good idea or whether your bike is ready for dyno runs.

Even at a quality dyno shop, your bike will be run up to redline in both gears lots of times. If you don't normally ride that way, there really isn't any reason to know what your peak hp is, and if your bike or tires arent up to snuff it might not be a good idea to do that.

If you have done mods with intentions for higher performance and haven't made it to a dyno yet, go for it. IMO one of the best satisfactions is seeing how much power an engine you built makes.

Tell us more about why you want to dyno the bike.

 
 

[MRieck]

Hi

I'm looking to do some tuning and dyno work on the auto. wondering if that's not recommended or anything to be mindful of?

Appreciate any input!

Where are you located?

[Bailgang]

I can only say from my own experience but putting my 750 on a dyno was the best money I spent on it. I've never owned a cb750 before so I had no idea what a well tuned 750 should run like but I knew something wasn't quite right and all plug chops did was have me chasing my tail, putting in on the dyno with an exhaust sniffer took all the guess work out of it because it showed me exactly where it was too rich and too lean. I didn't need the dyno operators tips or advice, I just needed the data and at that time knew exactly what I had to do. The 750 that I thought ran decent as it turned out was actually running like crud and once I had the data from the dyno and made the necessary changes my 750 literally woke up.

That shop only charged $30 for a dyno pull which I thought was a bargain however that shop has since sold it's dyno so they can have more work space and the only other shop around here that has a dyno wants $100 for a dyno run ..... and I'm not so sure I want to spend $100 for another dyno run should the need ever arise again.

[nixon]

Really appreciate your input...

1. Do you race? I am taking it to a historic track day and will more in the future. More so I run it pretty hard. Fork brace really helps

2. Is it running well? I'd say no. Running perfect prior to k4 cam and catbs installed. Valves done, dyna s ign n coils. I believe it's catbs. 120 jets to big, will try 110 still

a. If not, and you are comfortable with it, have you attempted to tune it? Not at all besides strobe light.

b. If so, what are you looking to gain? Smoother power thru range. Don't expect too much hp

3. Do you have any mods? As above with bread box box, ram air filter

4. Are you just curious about hp? If so that's fine, lots of people are. Kinda! More about getting her running well

5. Engine, trans, anything making any noise that isn't normal? Nope, perfrct

6. Is it shifting perfectly? Yes

7. Are you aware that tire manufacturers will not warranty their tires after a motorcycle has been run on a dyno? I am now

8. Is there a dyno operator with a proven record in your area? Lots of dyno guys these days are very very bad tuners. Yeah crew that race sohc here in Melbourne

The answers to those questions will help you get a little closer to determining whether it is a good idea or whether your bike is ready for dyno runs.

Even at a quality dyno shop, your bike will be run up to redline in both gears lots of times. If you don't normally ride that way, there really isn't any reason to know what your peak hp is, and if your bike or tires arent up to snuff it might not be a good idea to do that.

If you have done mods with intentions for higher performance and haven't made it to a dyno yet, go for it. IMO one of the best satisfactions is seeing how much power an engine you built makes.

Tell us more about why you want to dyno the bike.

 
 
[/quote]

[nixon]

guess im kinda more worried about burning the clutch out for some reason on the dyno

[MRieck]

guess im kinda more worried about burning the clutch out for some reason on the dyno

I wouldn't worry about that as long as the fibers are not burnt out POS (I/we have seen that). You can get new fiber plates.

[nixon]

guess im kinda more worried about burning the clutch out for some reason on the dyno

I wouldn't worry about that as long as the fibers are not burnt out POS (I/we have seen that). You can get new fiber plates.

little more involved i thought with the auto..not just easy access as per standard k ,f

[scottly]

guess im kinda more worried about burning the clutch out for some reason on the dyno

Unless there is already a problem, I wouldn't worry about it. BTW, any tire warranty issues would be tread-wear related, as the knurled drum tends to be hard on the tire. It's not really an issue, unless you are planning on doing 100's of dyno runs.    

[bear]

Who's the crew in Melbourne your thinking of taking it to?

Cheers,
Brian

[Old Moe Toe]

That shop only charged $30 for a dyno pull which I thought was a bargain however that shop has since sold it's dyno so they can have more work space and the only other shop around here that has a dyno wants $100 for a dyno run ..... and I'm not so sure I want to spend $100 for another dyno run should the need ever arise again.

$30 sure is a bargain!. I recently paid $500 (Aussie dollars) to get my Harley dyno tuned. It took about 3 hours, however seeing that it is fuel injected you do not have a great deal of choice.

[nixon]

T-rex