Leaded Race fuel and titanium valves

[Mackelroy]

The last 5 gallons I bought was from Kassons, it was about $11 pergal, that was bring my own jug from his 55 gal drums. That costed around $55.00. I dont know where prices are right now, but for the sealed can direct jug, I thought that %69 was a good price.

I can always use the can as a refill, My 5 gallon plastic motorcycle jug is 20 years old, it could split at any time.

I dont use enough for a 35 gal drum, 5 gallons last me 10 to 12 months.

 

[Mackelroy]

One thing I wonder, How does Honda keep winning the Baja 1000 if their motors keep failing?

Where is Yamaha in this race?

 

[sunruh]

honda does not use the crf250 nor the crf450.

they use the XR650. entirely different motor.

honda is the only one that cares about that title.
and if you want to win you either need johnny campbell or helgleven (spelling) and they were both with honda. your chances were a lot lower.

yamaha has won the paris-dakar race several times recently. where was honda in those?

 

[Mackelroy]

They used to run the xr650 , but they are running the crf450x to my knowledge.

Thats what they advertise also, there crf45x Baja winner several years in a row. Its on their website to. But I saw the bikes at baja and they were not xr650's.

 

[sunruh]

about time they switched.

for one, the crf450 is a lot easier on the valves than the crf250.

however, they still have some issues in oem form. but not like the crf250.

BUT (big but) they dont run oem now do they? NO!
that bike is so far from oem that even the color of red might be different that whats on the showroom floor.
plus it only has to do the one race. then it is gutted and redone.
which is what any serious race bike goes through. and honda is mega serious about that race. nobody else cares.
i bet they use a special fuel just for that race as well. as they should. may even be leaded.

yamaha won paris-dakar with a 2WD bike several years ago. where is the honda entry? where is their 2WD entry? yamaha was serious about that race and honda is not.
i think ktm is the only team serious about it now. with their 500lb bike.

 

[Mackelroy]

I know that Yamaha has a better reputation on the valve system, I was thinking maybe Honda actually fixed their issue, its been a few years since they originally came out.

But yeh I was down at woods several years ago with crf250 blown to bits in the service department. One guy quoted like 3 grand to fix it, and he was picking it up, the motor laid out on a push cart.

I noticed the Yam WR series is using the old valve sytem but the motocross version has changed, I hope the new systems is as reliable?

 

[sunruh]

the YZ and WR are identical. the ONLY difference is the timing on the exhaust cam and a wide ratio transmission. plus a light coil and funky epa carb [censored]. mechanically the motors are identical.
just as they are on the honda's R and X models. makes parts supply easy to maintain. very smart.

the unicam is very odd. for being such a supposed weight saver, why does not honda put it on their street bikes?
probably because the cbr600rr and 1000rr are already awesome motors with no valve issues that's why!

my buddy that owns DLR Cycleworks did 24 crf250r's in 04-05 and the dealerships in the area only sold 29. that is a LOT of bad valves! we made him a fake vanity license plate for his truck that said "Got Ti?"

i think honda has fixed their seat material to help out the issue. but that does not mean they are close to a blue or orange.

 

[Mackelroy]

I meant the New 2011 YZ, I dont think they are using the old 5 valve design, but the wr still has it.

I could be wrong , but thats what i remember reading

 

[Mackelroy]

I had to go back and check it had been a while, they redigned the motor backwards on the new yzf 450's starting in 2010 , I think the valve set up might have changed too.

But the WR450 still has the old design

Im just wondering if the same valve longevity is still there, as in the previous motors?

 

[sunruh]

jury is still out, but i have not heard of any issues.

the 250f still has 5 valves. we think that will change with the rear canted motor as well. maybe in '12.

 

[Cujet]

Originally Posted By: Mackelroy
One thing I wonder, How does Honda keep winning the Baja 1000 if their motors keep failing?

Where is Yamaha in this race?


The general consensus is that the Honda CRf450x engines have a 1500-1700 mile lifespan in dual sport use. Which, not coincidentally, has similar valve related stresses to high speed, off road racing.

The Yamaha's are not promoted in a similar manner. I'm convinced that a Yamaha, with similar financiers behind it would achieve similar speeds and have a shot at victory.

Interestingly enough, there was a Honda that outlasted others in desert racing. He was using leaded Avgas. It's not an ideal fuel for 4 stroke motocrossers, that's for sure. However the lead did "seemingly" result in zero valve problems. Teardown was impressive. Of course, this guy may have been limiting RPM and riding at non competitive speeds too. Simply too many unknowns.

 

[Mackelroy]

Sunruh runs full Lead on his bike, I dont know leads effect on the coated valves (if any benefit) . Ive only used it on steel valves.

Race lead is abrasive to carbon, I know that for a fact, thats why I like it.