Technical Max rpm

[smurth1984]

Hi what is the max RPM for a honda cadet gx160 sp RPM engine?
Running a 19/73 sprocket and clutch currently hitting 53mph at 6250.
Engine had a full rebuilt about 3hrs ago.
Will this improve?
Can I adjust the throttle leaver screw a bit more to gain a few more RPM
Thanks for the help and replys in advance

 

[Seanl]

6200 is where you want to peak. This is the tail end of the power band so if you're going over, drop a rear tooth. It'll improve over the next 10 hours running throughout the range but keep the revs at 6200 max and you'll gain power lower down where it's better used. Going as high as 6600 as your other post suggests will cause premature wear/damage to the engine.

 

[Wolemid]

Hi what is the max RPM for a honda cadet gx160 sp RPM engine?
Running a 19/73 sprocket and clutch currently hitting 53mph at 6250.
Engine had a full rebuilt about 3hrs ago.
Will this improve?
Can I adjust the throttle leaver screw a bit more to gain a few more RPM
Thanks for the help and replys in advance

As above 6.2-6.3 realistically is the absolute maximum you want to be hitting Ona Honda Cadet.

Drop the sprocket down to a 19/72, which should drop the revs to around 6k revs and then get your driver to carry more speed through the corners.

 

[smurth1984]

As above 6.2-6.3 realistically is the absolute maximum you want to be hitting Ona Honda Cadet.

Drop the sprocket down to a 19/72, which should drop the revs to around 6k revs and then get your driver to carry more speed through the corners.

Thanks kart on the trolley is hitting 7k revs as its not under load this sound about right also whats the best spark plug gap for best performance

 

[Seanl]

Don't know, I wouldn't chance revving it that high. Stick to standard gap with no additional spacing from the head, you aren't allowed to alter them when racing and it'll be checked under scrutineering. You really won't notice any difference on a 4 stroke Honda anyway.

 

[Wolemid]

Thanks kart on the trolley is hitting 7k revs as its not under load this sound about right also whats the best spark plug gap for best performance

You really shouldn’t ever run a kart engine up not under load. Especially waaaaay past any sort of revs you would use on a track.

Remember a Honda engine is a Generator engine, designed to run at 4K revs all day every day. Us just running them at 6.2k alone puts them under stress they arnt designed for, let alone bashing another 800revs on top of that.

Also regards revs, standard gaps are fine, more importantly is to find spark plugs which screw in the correct way. You may buy a pack of 10 plugs and only 2 screw in the correct way for race engines. These make the more difference than gaps

 

[LE#99]

We used to run to 6450 regularly without issue and as mentioned what are your low revs?
Another consideration is not all tracks work best chasing revs but as I say we never worried about running revs as high as 6450 as never had an issue. You'll have way more issues if the driver is double pedalling so make sure you don't have telltale overheat on the clutch and don't hear the engine labouring round the corners.

As for throttle lever this should be adjusted to allow the butterfly to fully open, don't limit the carb opening.

BTW
Are you talking about Tattershall gearing? If so you're way low, 19/75 maybe I think the driver I had out was 76 but he's new to it.
HTH

 

[smurth1984]

We used to run to 6450 regularly without issue and as mentioned what are your low revs?
Another consideration is not all tracks work best chasing revs but as I say we never worried about running revs as high as 6450 as never had an issue. You'll have way more issues if the driver is double pedalling so make sure you don't have telltale overheat on the clutch and don't hear the engine labouring round the corners.

As for throttle lever this should be adjusted to allow the butterfly to fully open, don't limit the carb opening.

BTW
Are you talking about Tattershall gearing? If so you're way low, 19/75 maybe I think the driver I had out was 76 but he's new to it.
HTH

Was at tattershall Sunday and was running 19/74 was the kart was doing great
Where of to fulbeck Sunday so was just making sure all was good with info i posted.
Got told to run 19/73 at fulbeck

 

[LE#99]

Was at tattershall Sunday and was running 19/74 was the kart was doing great
Where of to fulbeck Sunday so was just making sure all was good with info i posted.
Got told to run 19/73 at fulbeck

Fulbeck has long straights with only a couple of slow corners so it will be lower
Can't remember what we used to run. 19/69?

This is old but may help

http://www.ethanackroyd.co.uk/gearing/gearing.htm

 

[mandelbug]

This is a very interesting discussion. We run at Rye House and currently on a 20/81 gearing (sister to 19/77 which is common). We have the Alfano tapped in to the ignition switch after wrapping around the HT lead proved to be very hit and miss. I can see my son is entering Stadium at 6500 and had been toying with the idea of dropping down to 80 or 79 but worried about bogging him down out the corners. We have been having an issue with oil coming out through the fuel pump and I noticed when he wasn't entering at 6500 we didn't see the issue anywhere near as bad (still get a bit in the feed pipe)

Think we definitely need to drop down a tooth or two and get it tested.