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Discussion Starter #1
Just some random idea that there might be an adjustment (cam or crank angle sensor) that we could adjust to take advantage of 93 octane.

Any thoughts?
 

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I looked at the actual values of the timing with the Honda scan tool and was surprised to see some high numbers going on already. The bike is running advance in the 60's at times and that was just revving the engine in neutral. I'm not sure if the triggers are adjustable though. The real upgrade would be to raise the compression. Shaved head?
 

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I looked at the actual values of the timing with the Honda scan tool and was surprised to see some high numbers going on already. The bike is running advance in the 60's at times and that was just revving the engine in neutral. I'm not sure if the triggers are adjustable though. The real upgrade would be to raise the compression. Shaved head?
As for head shaved that is not good idea keep in mind that by doing that you get losser timing chain tension and you change valve timing. Your best option is higher compression piston that better way to go.
 

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Discussion Starter #7
Found a parts diagram online. There's a bank angle sensor on the head. This is where the ECU gets its crank angle signal.
 

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Shaving the head 0.010 is not going to effect the chain. It has an automatic tensioner for a reason. It does streach. I brought my bike to a company yesterday for R&D and head work is one of the major things they are doing to it.
Sorry but any time you start machining the head down it slight effect it will retard your valve timing, loosen your timing chain oh it has nothing to do with automatic tensioner that there to take up slack.
This what happing It basically shifts the torque range up or down. If retarded, the peak torque will be moved up. If advanced, it will move the peak torque curve down. Usually, retarding from the stock setting will increase the peak HP and visa versa.

Good find cgherrington3 so it has a cam or crank sensor like a car but they called a bank angle sensor I wonder it knock sensor to.
 

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I looked at the actual values of the timing with the Honda scan tool and was surprised to see some high numbers going on already. The bike is running advance in the 60's at times and that was just revving the engine in neutral. I'm not sure if the triggers are adjustable though. The real upgrade would be to raise the compression. Shaved head?

Of course, they use heap of timing where there is no load on the engine.

If it was to run a 3d timing map it could be much different at loads
 

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Discussion Starter #10
I don't think it has a knock sensor. If it did the rattleboys would be complaining about performance as well.

Now, to find out if there's any adjustment to the bank sensor.
 

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Sorry but any time you start machining the head down it slight effect it will retard your valve timing, loosen your timing chain oh it has nothing to do with automatic tensioner that there to take up slack.
This what happing It basically shifts the torque range up or down. If retarded, the peak torque will be moved up. If advanced, it will move the peak torque curve down. Usually, retarding from the stock setting will increase the peak HP and visa versa.

Good find cgherrington3 so it has a cam or crank sensor like a car but they called a bank angle sensor I wonder it knock sensor to.
What you just said make no sence, "loosen your timing chain oh it has nothing to do with automatic tensioner that there to take up slack." Your saying shaving the head will losen the timing chain but the tensioner doesnt do anything? All my MX bikes have shaved heads and my CRF is close to the same engine design as the CBR but unicam and it had nothing but posative effects from doing it.I can see maybe .035 or .050 causing issues but somthing as small as .010 i don't think so " sorry for the thread jack"
 

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What you just said make no sence, "loosen your timing chain oh it has nothing to do with automatic tensioner that there to take up slack." Your saying shaving the head will losen the timing chain but the tensioner doesnt do anything? All my MX bikes have shaved heads and my CRF is close to the same engine design as the CBR but unicam and it had nothing but posative effects from doing it.I can see maybe .035 or .050 causing issues but somthing as small as .010 i don't think so " sorry for the thread jack"
What I mean by that
Even at .010 shaved that about 0.4 degree change of timing at .050 that about 2.3 degree of change on the cam timing degree and the automatic tensioner only to take up the slack becuase the chain pitch it self has a fixed length for each gear teeth, So the lower you take it down you change center line length from cam to crankshaft that why it not good idea to change head deck height on over head cam.

CRF is close to the same engine design as the CBR
There not even remotely close to same engine design far from it.
CRF Bottom end is just like a 2-stroke engine in fact it base on it and if it wasn't Powroll R&D project CRF150cc the Honda 450, 250 and 150 would have most likely have never have born to what it is today.
 

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I don't think it has a knock sensor. If it did the rattleboys would be complaining about performance as well.

Now, to find out if there's any adjustment to the bank sensor.
You know that advances timing when the engine start knocking or look up pulse detonation, pre-ignition‎ or engine knocking which is need on EFI and higher compression ratio motor becuase some people do use high grade gasoline you know Regular vs Premium octane gasoline.
 

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I get what your saying, but as far as saying shaving the head on an overhead cam motor is a bad idea i disagree, I have a buddy who races sport bikes for a living and they shave their heads and use different thickness head gaskets to fine tune it. But on the other note they have adjustable cam gears. Either way all this shaving talk the company that is using my bike for R&D know what they are doing and it is getting shaved.
 

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the benifits of shaving a head far outway any insignificant change in cam timing

The best way to change the ignition timing will be with either a standalone or a piggyback ecu which is the way id go.
 

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My understanding is that the bank angle sensor is there to shut off the fuel injection and ignition should the bike tip over while running. It's in the upper fairing not anywhere near the crankshaft. The CKP sensor handles ignition timing information to the ECM. Anything is possible but it's doubtful that it is easily adjustable.
 

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The ignition does seem to be done via the flywheel based on the parts fiche. Offset woodruff keys would be the simplest option, although if you're discounting the impact of a degree or two in cam timing will you actually take the time to see if mucking with ignition timing will be a real gain? You'll also be altering when the EFI fires by playing with that pickup which can have it's own impact.
 
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