tune up

[modest]

I have a 1977 cb 750 with a 71 engine i bought from my friend about 4 months ago maybe 3, i use it everyday its my transportation, i was just wondering does the timeing, points, valves and carbs need to be messed with much, i know he said he did all that about 6 months ago i mean bike sounds good engine isnt hessitating i just feel maybe it could maybe not be getting up to speed as quick as it could?? any thoughts thanks...

 

[Big R]

I don't think it's the time between tune-ups that is important (unless the bike hasn't run for like 10 years), but the mileage. It should be in the service manual. If I recall, mine calls for a decent tune-up every 600 miles or something.

Besides, unless you break something in the process, a tune-up is always a good thing!

 

[crazypj]

You tune musical instruments, you SERVICE vehicles
service interval is 1,500 miles, do at least oil and filter and check points/timing, air up tyres (should check at least every week)
Valve adjustment should be checked
Carb synch about 3~6,000 unless it's running rough, clutch noisy, etc

PJ

 

[Rocan]

then what do you call it when you build up a new motor and need to get everything running perfect (carb wise etc).

if its not servicing, then what is it, "adjusting"

 

[boingk]

You service vehicles, but you tune carburettors! BAM!

The 1,500 mile interval should be easy to live with, and a good way of reducing the cost of oil changes is to buy a bulk/trade pack of oil. Over here they are only around AU$70 for something like 6 gallons or more. That way you can do your oil changes as frewuently as you need to without stuffing around and buying more oil - plus what you save on changes you can spend on modifications or other bikes.

On the oil front, I'd change once a year if you don't get to the milage interval. Often this will mean you've been doing short trips, and these are the worst kind for oil life anyway as the engine doesn't get to burn off any condensation or deposits that may collect in the oil.

Cheers - boingk

 

[fastbroshi]

then what do you call it when you build up a new motor and need to get everything running perfect (carb wise etc).

if its not servicing, then what is it, "adjusting"

I've always called it "dialing it in".

Valves should be adjusted every 300 miles I think, if it's anything like the 550s. Don't forget to adjust your cam chain when the motor's dead cold. I usually do the points when I'm doing the valves. Have you heard of Hondaman over on the SOHC forum? I have no affiliation with the guy, but his ignition unit is supposed to just about eliminate points wear. I haven't checked mine since installing it about 100 miles ago, but it sure starts easier.

 

[Wee Todd]

I've owned Nortons,,and there service intervals are way beyond 300 miles(high maintanence motorcycle),,,,you mention a 550??? you can run a .001 over on both valves and pound the living shit out of them on the track or street.....they will mis shift to 12 grand..bullet proof motors..set your junk once a year,,,a well maintained set of points and condensers will last several years

 

[fastbroshi]

I've owned Nortons,,and there service intervals are way beyond 300 miles(high maintanence motorcycle),,,,you mention a 550??? you can run a .001 over on both valves and pound the living shit out of them on the track or street.....they will mis shift to 12 grand..bullet proof motors..set your junk once a year,,,a well maintained set of points and condensers will last several years

I just mentioned in passing to my neighbor I had a 550 I was building to road race and he mentioned he DRAGGEd his 550 a while back, said he had the rods heat treated and shot peened and he shifted at 13 all the time. Pretty cool.

 

[Wee Todd]

Mr Fastbroski the only down fall of this motor is the primary chain...and it is really not a down fall,,it's a hyvo design and when worn out, it stretches,,and buzz saws into the lower oil gallery of bottom crank case.I changed mine to the tune of a $130.00 ,,,a street\strip cam,4 into 1,26-28mm carbs will make these motors performe on a budget

 

[Wee Todd]

oops forgot to mention,,you can stuff in cb 750 pistons to bring it to 590 cc(machined)or cb 550 night hawk pistons 61mm(machined , deck the crown it should work :)