Do built motors use tighter valve clearances

Hey, you hear Ollie left? Taking Catfish's job at Yosh

 

I don’t trust you

 

Congratulations

 

How many of you who say tighter is better have done scientific testing on a dyno? I have done it, and I know guys at Yosh and Yamaha who have done it. Results absolutely do not back up what you claim. Good luck refuting science.

 

Sorry to hear that. I love Catfish like a brother, but I knew he was going back to the GWN. Ollie...

 

I'm one of those that have done testing on a dyno. My own dyno.

I have specific references to which bikes back up my experience.

I won't speak for every make and model because that would be ignorant.

If it helps, I can add a few more models.

You of all people should know that every motor reacts differently to changes especially in cam profiles and valve train.

you seem like you're looking for an argument, I'll just remind you that every single day, science and facts are modified and adjusted as more knowledge is gained.

 

Nope. This forum is full of ignorance. I hate arguing. I have built motors that have been on pole for the 200 and have won many races. I try to help, and then people who seem to know everything protest. I just offer my scientific help.

 

10'years ago nobody would have said Pneumatic valves are a benefit in motorcycle racing engines.

5 years ago nobody would say that you can get 200hp out of a twin cylinder motor naturally

10 years ago there was no way a stock 600 would produce 120 hp

I mean, I can go on and on and on. But I'd hope you would see my point. I don't think ANYONE would would doubt your abilities. That being said, just because what works on an inline 4 motor, won't always work on a triple, or a twin, or a single....

Congrats on being on pole for Daytona 200. It's a good feeling. I've never sat in pole for that race, but I shared many a winners circle and many podiums with my motors.

For instance in XR750's in situations where the motors have won races, the valves are set at Zero. But we are talking pushrod motors.

In some 675's where we led some speed traps in AMA supoesport and superstock they were also on the tight side.

Again, just because we both use "science" doesn't mean we can't reach different successful conclusions depending on the type of motor. This is why dyno time is critical.

Hell, I bet I sat on the dyno for a solid week just playing with cam timing numbers which is why you would consistently see my motors as some of the fastest "legal" 675's in the country to this day.

 

I like tight. One less variable. Race camshafts are designed for a reason. Valve clearance is a maintenance requirement, like adjusting a drive chain. Granted differences between tight and loose mean nothing in a race compared to rider action, but I cant effect that once the bike has left pit lane.

 

Some people believe in rotella and some dont

Keep em tight enough they clean the piston

 

Looks like you might have a limp dick valve spring.

 

nah, Just waited to long to adjust... no damage occurred (at least no measurable damage)

this is .030" p2v @ .002" valve clearance..

 

I found no discernible difference. So make 'em tight, and enjoy. Every single kit racing manual that the Japanese produce has you adjust lash to the maximum. Might there be a reason for that? Not sure. All I know is my research says: No difference. And my friends at Yosh say, "we agree." Again, who cares? It seems not to matter. Those who say tighter is better based upon seat-of-the-pants tuning might need to do some testing.

 

Ok so I had thought that my motor had a manual tensioner in it since it has the hex bolt head. Once I unbolted it I found out it was spring loaded. Now going to assemble everything and I can't figure out how this thing locks in place to install it. I can lift the lever and push it back in but don't know how to keep it there and then release it. I'm assuming the hex bolt has something to do with it but it's tight enough that gently (and I do mean gently) clamping the body in a vice I couldn't spin it either way. So whats the story here?

 

Also is that hole on the side an oil passage from the block. So it appears that oil pressure also pushes on this thing?

 

Got a manual?

You should.

Unscrew the bolt. It will then be clear. Yes there is oil pressure. Replace the gasket.

Get a manual. They’re cheap or free online.

 

Remove the hex bolt and use a small flat tip screwdriver to wind the plunger into the body. Then carefully insert the tensioner into the head without letting the plunger release, and bolt it in nice and snug. Once you get it bolted into place, release the plunger and you are done.

 

Take off the 8mm bolt there. Inside is a slot that you turn 90 degrees and will lock the tensioner when it is compressed so it can be reinstalled. You need a little flat head screw driver or make a tool.

 

I got one and the style it says that came with it you push it in and hold in place with a pin. Then through an access hole I don't have on mine you remove it. Anyone know which of these motors had these holds on the side of the head to do this and which didn't?

So the hex bolt is just a plug I take it? It's a 12mm too if that changes anything

 

Remind me which motor you have.