I raised my horn several years back after reading the late XSJohn's posts describing his concerns and what he had done to improve airflow to the front of his engine - dunno if they still can be accessed on this site, but if so, well worth a read. I have no capability to take temp readings, so dunno if it made much difference - just seemed intuitively to be a useful (and very easy) thing to do.
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Oil temps, how hot are you running?
- Thread starter weekendrider
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Interesting Aldo - I'll take a look at doing that too.
I'm not sure how big a difference it would make to the engine temperature, but it should make the horn louder than having it point at the top of the cylinder head.
On the issue of horns, I had installed a Fiamme Freeway Blaster to supplement Lucille's cute but relatively useless little "meep-meeper" - but the Fiamme recently died, likely from water ingestion and the 41 year old OEM horn is still "meeping".
Dammit. I don't want to sound the "the roadrunner" teasing the coyote out in the desert - I want to sound like an out of control concrete mixer screaming "GET THE F@CK OUT OF MY WAY @SSHOLE!!!" when some idiot in an Escalade or BMW tries to attack me.
I guess I'll have to buy another Fiamme and then find a way to mount it that points the mouth away from the stream of water when I ride in the rain.
Pete
I'm not sure how big a difference it would make to the engine temperature, but it should make the horn louder than having it point at the top of the cylinder head.
On the issue of horns, I had installed a Fiamme Freeway Blaster to supplement Lucille's cute but relatively useless little "meep-meeper" - but the Fiamme recently died, likely from water ingestion and the 41 year old OEM horn is still "meeping".
Dammit. I don't want to sound the "the roadrunner" teasing the coyote out in the desert - I want to sound like an out of control concrete mixer screaming "GET THE F@CK OUT OF MY WAY @SSHOLE!!!" when some idiot in an Escalade or BMW tries to attack me.
I guess I'll have to buy another Fiamme and then find a way to mount it that points the mouth away from the stream of water when I ride in the rain.
Pete
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very interesting thread and very relevant with the current temperatures.
I'm kind of surprised that nobody yet ,(other than Bob
),has really mentioned the part the exhaust valves play in the overall temperature of the engine.
Someone needs to do some temperature testing with all the various yamaha recommended valve settings throughout the XS650 model range
There is a really interesting article written by a Brit Engineer who specializes in building XS650 /850/rephased engines for racing. Howard of Smedspeed.
Here is the article which is a thoroughly interesting read with a cup of coffee. http://www.smedspeed.co.uk/tech.html
Howard did some intensive testing of the various valve train components,valve lift against cam rotation etc of the various models together with a study of how long the inlet and exhaust Exhaust valves were actually held slightly off the valve seats each cam rotation. It turns out to be a huge!
The slow ramp of the later cams give a Inlet cam event total of a staggering 395 degrees ! ( 93+180+122), with absolutely no benefit whatsoever in terms of increased inlet flow but a significant reduction in heat transference from valves to seats to head fins.
Howards conclusion was summed up thus.
'The late XS650 cams set at .002" intake tappet setting is ridiculous. I can’t think of another OHC engine with valves this size that has such small clearances, the camshaft has a run-out of over 0.002 in many cases and setting the tappets to this small clearance will allow the valve to stay open perpetually. It is an effort by Yamaha to reduce engine noise, but this is not the way to do it.
I set all the tappet clearance at the early settings of 0.006 and 0.012. It allows in more oil, and allows for a generous growth in the metal parts, remember….. A loose tappet is a happy tappet.'
I'm kind of surprised that nobody yet ,(other than Bob
),has really mentioned the part the exhaust valves play in the overall temperature of the engine.Someone needs to do some temperature testing with all the various yamaha recommended valve settings throughout the XS650 model range
There is a really interesting article written by a Brit Engineer who specializes in building XS650 /850/rephased engines for racing. Howard of Smedspeed.
Here is the article which is a thoroughly interesting read with a cup of coffee. http://www.smedspeed.co.uk/tech.html
Howard did some intensive testing of the various valve train components,valve lift against cam rotation etc of the various models together with a study of how long the inlet and exhaust Exhaust valves were actually held slightly off the valve seats each cam rotation. It turns out to be a huge!
The slow ramp of the later cams give a Inlet cam event total of a staggering 395 degrees ! ( 93+180+122), with absolutely no benefit whatsoever in terms of increased inlet flow but a significant reduction in heat transference from valves to seats to head fins.
Howards conclusion was summed up thus.
'The late XS650 cams set at .002" intake tappet setting is ridiculous. I can’t think of another OHC engine with valves this size that has such small clearances, the camshaft has a run-out of over 0.002 in many cases and setting the tappets to this small clearance will allow the valve to stay open perpetually. It is an effort by Yamaha to reduce engine noise, but this is not the way to do it.
I set all the tappet clearance at the early settings of 0.006 and 0.012. It allows in more oil, and allows for a generous growth in the metal parts, remember….. A loose tappet is a happy tappet.'
Agreed Peanut - that's why they call it a "TAPpet.
The Smedspeed article is very interesting and Peanut referred me to it some time ago - Thank you Peanut. I think this article is implying that the old specification is also being applied to the more modern XS bikes also. The topic of valve adjustment comes up many times on this forum but I have yet to hear of anyone using the old 0.006 and 0.012 specification on the more modern XS bikes. Has anyone tried it?
I am currently using the 0.003 and 0.006 specification. For a week or two I did try 0.004 and 0.008 but reverted back to the factory specification, not for any particular reason, just did not know how I would quantify the benefits except to assume my valves where being cooled better.
Regarding oil temperatures: Last week when the air temperature was 22 Celsius I traveled at 50 - 60 mph for 18 miles down a dual carriage after 50 miles of mixed riding. When I pulled into my home I quickly stuck a thermocouple into the oil filler to get a gearbox oil temperature. I measured exactly 100 Celsius. I am pleased to see that this is a typical sort of value.
I am currently using the 0.003 and 0.006 specification. For a week or two I did try 0.004 and 0.008 but reverted back to the factory specification, not for any particular reason, just did not know how I would quantify the benefits except to assume my valves where being cooled better.
Regarding oil temperatures: Last week when the air temperature was 22 Celsius I traveled at 50 - 60 mph for 18 miles down a dual carriage after 50 miles of mixed riding. When I pulled into my home I quickly stuck a thermocouple into the oil filler to get a gearbox oil temperature. I measured exactly 100 Celsius. I am pleased to see that this is a typical sort of value.
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yes you're right there doesn't seem to be many sources ,if any, of anyone doing any meaningful research into the valve setting conundrum except Howard.
He has apparently used the earlier XS-1 settings on all his engine rebuilds and I cannot fault his test proceedures, results and conclusions.
Yamaha themselves changed the recommended valve settings 4 or 5 times over the years, sometimes within the same year . The service sheets make interesting reading.
Two other interesting facts that Howard raised was that the early cams had a slightly more aggressive profile and the early valve settings give a significant improvement in compression too ! Together with the improved heat transference I personally cannot see any sensible justification for sticking with the smaller clearances and lots of good reasons to open them up.
As soon as I get shot of my Sciatica I'm opening my clearances up for sure and install and monitor my engine temperature sensor .
He has apparently used the earlier XS-1 settings on all his engine rebuilds and I cannot fault his test proceedures, results and conclusions.
Yamaha themselves changed the recommended valve settings 4 or 5 times over the years, sometimes within the same year . The service sheets make interesting reading.
Two other interesting facts that Howard raised was that the early cams had a slightly more aggressive profile and the early valve settings give a significant improvement in compression too ! Together with the improved heat transference I personally cannot see any sensible justification for sticking with the smaller clearances and lots of good reasons to open them up.
As soon as I get shot of my Sciatica I'm opening my clearances up for sure and install and monitor my engine temperature sensor .
Hitndahedfred
Do I look like a people person to you?
=========================================================
Being a greenhorn here I must agree that with these early engines.
If the engine isn't making those tappet noises,, I expect something to be wrong. Those sounds tell me all is well there.
I regularly set my valves to .006 intake and .010 exhaust. I tried others but these numbers seem to be my engines "sweet spot".
On another note,,, are those dipstick thermometers still available?
Yup - you want to speak with a chap named Dogbunny - he makes them. I've bought one for each of my bikes and they work well!
Pete
Pete
Hitndahedfred
Do I look like a people person to you?
===================================
THX Pete,,
Such an old post I was hoping he was/is still around.
He is - I got my thermodipsticks about a month ago.
One key point - BE SURE to read and follow his instructions to the letter to ensure that your unit is properly indexed to the thread start on the dipstick hole of your bike.
Frankly, I muffed it and have had to substitute a thicker o-ring on mine so that I read read the thermometer easily. Dohhh.
If I had read the instructions more carefully, it would have been better.
One key point - BE SURE to read and follow his instructions to the letter to ensure that your unit is properly indexed to the thread start on the dipstick hole of your bike.
Frankly, I muffed it and have had to substitute a thicker o-ring on mine so that I read read the thermometer easily. Dohhh.
If I had read the instructions more carefully, it would have been better.
Hitndahedfred
Do I look like a people person to you?
Sent him a PM,,,Hopefully will hear back soon. This is one thing about these engines I am not feeling "safe" with yet.
I got over the engine noises,,shifting sounds and such but I do worry about heat.
Would be nice to look down and instantly see whats going on,,temp wise.
I got over the engine noises,,shifting sounds and such but I do worry about heat.
Would be nice to look down and instantly see whats going on,,temp wise.
Well, they're air cooled (no rad to clog or water pump or fan to fail) and they have pretty primitive carbs (no EFI sensors to go nuts in the dark) - although with some experimentation and work, they can be made to run quite well.
I guess the point is that as long as there is good clean oil and the jetting is sorted out - they shouldn't over heat too easily. Sitting in traffic on a 90F day might do it - but even then, it would take quite a few minutes.
That is actually the main reason I bought a thermodipstick for each bike.
I guess the point is that as long as there is good clean oil and the jetting is sorted out - they shouldn't over heat too easily. Sitting in traffic on a 90F day might do it - but even then, it would take quite a few minutes.
That is actually the main reason I bought a thermodipstick for each bike.
I've been all over the map with my '71.
0.006/0.012 and 0.005/0.010 makes my engine clatter, but perky.
0.003/0.006 quietens it, and calms it down. Old man tolerable.
I'll probably go back to 0.005/0.010
Then see what the hi-vol oilpump and carbs think.
Haven't heard of anyone running the looser spec on later models...
