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I was thinking of going out and "trying" the 2.0 cam I got from Terry 6 months ago. I like low end so I have been hesitant to change the 1.0 cam to the 2.0. But if it ain't much trouble, I would just to see how it performed. So I'm trying to recall.................. will the head come off without pulling the motor. No sense in pulling the gas tank, etc, if I have to pull the motor.... because I would consider it more trouble than it's worth considering this is no longer my go to bike, but a spare, plus as is now, the 2.0 cam has never even had the box opened, so I could resale it. I plan to keep the bike, so  if zero low end is lost with the 2.0???????, I would go to the trouble. It's not that it is a major task to pull the motor, I just need motivation to do so. 

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Thinking , recalling this motor,  I bet I could lift the head enough to remove and replace the cam 

Edited by 1gr8bldr

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I stripped it down, needing to adjust the valves even If I leave it the same cam. Looking at it, For sure the head would likely not come off. Trying to recall, maybe its the crf100 that does come off easy still mounted on the bike. But tilting the head and pulling the cam out, they may be possible????? But able to put gasket sealer back in correctly would likely be an issue???? Anybody done it that way? Anybody care to comment on low end loss with the 2.0?

Edited by 1gr8bldr

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I stripped it down, needing to adjust the valves even If I leave it the same cam. Looking at it, For sure the head would likely not come off. Trying to recall, maybe its the crf100 that does come off easy still mounted on the bike. But tilting the head and pulling the cam out, they may be possible????? But able to put gasket sealer back in correctly would likely be an issue???? Anybody done it that way? Anybody care to comment on low end loss with the 2.0?

Depends on how large the engine size is, how much compression the engine has, if the cam is specifically degreed in for more low speed power or top end power, depends on header diameter and how the intake port has been ported. (High velocity (low rpm enhanced) or high volume ( high rpm enhanced)

Depends on a Stock 230f rev box or Pro Com rev box.

And the carb choice your using makes a difference.

What cam are you comparing the 2.0 with?

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2 hours ago, adnohguy said:

Depends on how large the engine size is, how much compression the engine has, if the cam is specifically degreed in for more low speed power or top end power, depends on header diameter and how the intake port has been ported. (High velocity (low rpm enhanced) or high volume ( high rpm enhanced)

Depends on a Stock 230f rev box or Pro Com rev box.

And the carb choice your using makes a difference.

What cam are you comparing the 2.0 with?

I currently have the 1.0

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LOL, may be an idea for another day now. I split the cases on a KX250 today, so I will be working on it instead in my spare time

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LOL!

11:51..............It's not that it is a major task to pull the motor, I just need motivation to do so. 

12:22..............I stripped it down, needing to adjust the valves even If I leave it the same cam. Looking at it, For sure the head would likely not come off.

What piston is in the engine?  If you have in the 10.5:1 neighborhood I believe the 2.0 is better at every rpm.

Is the head stock?  Not ported or cleaned up?

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20 hours ago, 1gr8bldr said:

I currently have the 1.0

If you decide to proceed with the 2.0, I'd be interested in taking the 1.0 off your hands.

Still planning to ride Brushy this weekend?

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1 hour ago, sneaky98gt said:

If you decide to proceed with the 2.0, I'd be interested in taking the 1.0 off your hands.

Still planning to ride Brushy this weekend?

Yes, for sure. Looking forward to it. Our bikes are in the suspension shop right now, my bike did not really need anything but my son's was way under sprung. Supposed to get them back in time to ride this weekend. Since we have never been there, you can be the guide. We get tired fast so we might better ride the hardest   trails first. 

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2 hours ago, MetricMuscle said:

LOL!

11:51..............It's not that it is a major task to pull the motor, I just need motivation to do so. 

12:22..............I stripped it down, needing to adjust the valves even If I leave it the same cam. Looking at it, For sure the head would likely not come off.

What piston is in the engine?  If you have in the 10.5:1 neighborhood I believe the 2.0 is better at every rpm.

Is the head stock?  Not ported or cleaned up?

Wosner 67, thin gasket, stroker, Terry did the valves, I believe he said he lightly ported/cleaned it up. Stainless Outlaw Exaust. Bearings wrong for KX250 so got some time waiting on them. 

Edited by 1gr8bldr

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How critical is the line up marks on the cam chain sprocket to the housing? I swapped the cam but if I go 1 tooth either way, I am equally off. Wonder id rotating 180 degrees changes a 1/2 tooth. I hope that it will. As of now it is slightly off. If not, then...... this was a waste of my time. Felt like a fat man riding an crf100

Edit, turning 180 degrees changed nothing, still off slightly. I started to go ahead and switch back but I'll wait to hear from the experts  about the timing before I do

Edited by 1gr8bldr

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With cam chain stretch and also using a thinner or single layer head gasket, you will have slack in the cam chain that will slightly retard your cam timing when the tensioner takes up the slack.... 

The result would be that the left mark would be a little high and the the right mark a little low.... Lagging behind a bit while.rotating counterclockwise.... Normal... Not perfect, but normal...

Your 1.0 cam would have been in the same position , so your swap would still have a relative comparison...

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How critical is the line up marks on the cam chain sprocket to the housing? I swapped the cam but if I go 1 tooth either way, I am equally off. Wonder id rotating 180 degrees changes a 1/2 tooth. I hope that it will. As of now it is slightly off. If not, then...... this was a waste of my time. Felt like a fat man riding an crf100
Edit, turning 180 degrees changed nothing, still off slightly. I started to go ahead and switch back but I'll wait to hear from the experts  about the timing before I do


Unless one uses a degree wheel to set the cam exactly where it needs to be, it's a compromise at best and your bike engine will never run to its full potential....
Unless your extremely lucky

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On my 254 stroker going from 1,0 cam to thin head gasket and 2.5 cam. No loss of low end major power boost every where. 1st/ and second gear on pavement would hardly lift the front wheel.(not pulling up on bars) Now unless you let off it flips over backwards. Big time bottom end with over rev on top. I rode Non stroke 240 big bore.ported head/pipe/carb/2.5 cam/big valve. No bottom end screams 3/4 top end. Would not work for my type riding. Hard slow mountain climbing single track. 

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On my 254 stroker going from 1,0 cam to thin head gasket and 2.5 cam. No loss of low end major power boost every where. 1st/ and second gear on pavement would hardly lift the front wheel.(not pulling up on bars) Now unless you let off it flips over backwards. Big time bottom end with over rev on top. I rode Non stroke 240 big bore.ported head/pipe/carb/2.5 cam/big valve. No bottom end screams 3/4 top end. Would not work for my type riding. Hard slow mountain climbing single track. 


Perfect example of post # 4 above.

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How do you know what degree is best? It seems like someone would make a cam chain sprocket with holes drilled for different degrees, not elongated. Should be enough space for 5 settings [10 holes] to physically try. Would be so simple to just remove the chain cover, two screws, rotate. 

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What would be the best "degree", % advanced or retarded timing?. I suppose it varies per builder, but I expect there may be  a majority vote on this. With the cam stretch I have, before I replace it, I could try it, it being advanced or retarded, it being about 1/2 tooth off. Hmmmm, wonder what degree 1/2 tooth is? 

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Problem with cam sprocket cut for different degrees of advance or retard is that the sprocket would still show up at the position the timing chain slack would have put it in... But the cam position relative to the sprocket , would have changed...

In general, retarding a cam adds top end... Advancing adds bottom end... I have never gone beyond 6 degrees either way...

"Straight up/on spec" is always the best start point....

A single tooth on a yz cam ... Is over 22 degrees... Don't do that

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9 minutes ago, mixxer said:

Problem with cam sprocket cut for different degrees of advance or retard is that the sprocket would still show up at the position the timing chain slack would have put it in... But the cam position relative to the sprocket , would have changed...

In general, retarding a cam adds top end... Advancing adds bottom end... I have never gone beyond 6 degrees either way...

"Straight up/on spec" is always the best start point....

A single tooth on a yz cam ... Is over 22 degrees... Don't do that

I'm 1/2 tooth off now with the chain stretch.... so I guess that is about 11 degrees?????

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