YZF vs. CRF - Maintenance

[pdmoyes]

First off, this is not a bashing thread, I'm just trying to compare the maintenance schedule between a YZF450 and CRF450. My cousin claims that they are the same for both bikes and I strongly disagree. I would think the YZ would need fewer checks to the engine design.

So if you YZF and CRF owners could divulge what your manuals recommend, I would appreciate it.

[UnsafeHaven]

Well i don't have any information from a manual, but i have two friends, one has a yzf. He doesn't take care of it at all, never changes the oil, and seldomly cleans the air filter. He beats the crap out of it, and is happy to admit it. He has been riding for 2 years now, it has lost a little power, and is not as fast as it used to be, but still runs well and it taking its beating like a champ.

My other friend has a crf, he always cleans air filter, changes oil, spokes, you name it he does it, he has gone through three tops ends (valves), and vows to never buy another honda, and they both have had their bikes for about the same amount of time. So i hope this helps you out a little, yz is the way to go out of those two IMO. ok later

[Woody_393]

I really think the YZF requires less "fixing", but the maintenance should be the same or similar.

I've had my CRF for 3+ years and have put new valves, springs, and piston/rings in it about 16 hours ago (motor hours).

But that doesn't mean you don't have to check the valves on both bikes, because you do. The difference would be that the CRF requires shimming more often, and then requires valve jobs on occasion. The YZF probably wouldn't need one yet, but you'd still have to check the valves and shim it.

[Red Rider 943]

They're the same.

[stimps]

I have neither, But have worked on a few and the Honda definetly has a bit of a bad reputation for valve replacement and regular adjustment. The Yamaha on the other hand seems to be pretty bullet proof. Do a search and you'll probably find a pattern to back that up. They certainly are not the same when it comes to valve wear. Do some research.
Obviously both should be serviced at similar intervals, just the Yamaha lasts much longer if neglected. If you buy new and sell each season they're probably as good as each other.

[AKColby]

Originally Posted by Red Rider 943

They're the same.

Which one do you have?

[RMZracer212]

Red Rider has neither he rides a 2 stroke, so he really does not know what he is talking about. But, I am a YZ rider and have not really had any big problems out of it. I have had 1 intake get tight, but it was only .02 out. I have a few friends ridin CRFs and they have had intake valve problems.

Clay

[Faded]

Originally Posted by YZFracer212

But, I am a YZ rider and have had really any big problems out of it.

Okay - I'm done for awile!!!


We've talked about this before, click here if you're interested.

[Aus_Rider_22]

Originally Posted by Woody_CRF

I really think the YZF requires less "fixing", but the maintenance should be the same or similar.
.

Quote of the thread!

[Florida 393]

I'll try to calm this down a bit. (Hint, Hint said the mod)

I own an '02 YZ 426F and change the oil after every third race/practice. If it is unusually dusty or a mudder outting I change the oil after I get home regardless of time. Oil filter gets cleaned every oil change and replaced every third change. Air filter gets cleaned after every outing. All bearings get greased three times a year unless we had a lot of muddy sessions. Bearings get replaced yearly (Linkage, dog bone, wheels, steering head and swing arm.) The chain gets removed at home and soaked in solvent (non-O ring, don't start with me on the o-ring vs. non sealed) and wire brushed until it is clean and grit free. I lube it when I reinstall it.

If that seems excessive so be it, I am an engineer and tend towards the conservative, read anal if you wish, side on maintenance: .

Bill

[RMZracer212]

You had to bring that back up didnt you. That bike that locked up was also ran 2 laps with out oil before it locked up. I added oil and it started back up, it took lie 2 yrs to lock up after no oil. That is pretty good I think. My friends has 2 04 CRFs both with junked heads, waiting on back ordered parts from honda. He is on his 6th intake valve. He has to shim them like every 4th ride.

Clay

[Florida 393]

I waited 10 days to let things calm down. I know for a fact there are a lot (read in the thousands) of both bikes in use. We hear of the problems because people get angry and talk about what they don't like. When things are going okay we ride and keep to our selves.

Both the YZ 450F and CRF 450R are strong performers and they both require maintenance in the form of oil changes, valve clearance adjustment and scheduled replacement of critical parts. It depends in large on how the bike is maintained and how hard it is raced.

Yes a few of any model will have defects in parts or assembly errors. Some valve and valve seat problems cropped up on a few Hondas, some clutch problems were a bother on the first year YZ 450F. The Suzuki/Kawasaki 250F models have had some valve, valve spring and clutch spring problems. But in these cases not every bike of a make/model was defective.

WoodyC has had a CRF 450 that has been by in large a sterling performer, my YZ 426F has been largely trouble free and Jedi and his son have CRF 250R bikes with a lot of racing on them. Regular valve, oil and filter and adjustment maintenance were required for all. We have all also made modifications to our bikes to make them suit them. John did a Pro Circuit valve and valve spring job on his RMZ even though it was running strong. I could go on and on with member bikes and bikes I know locally.

Bottom line to me as an active rider and inerested party from an engineering point is that the bikes are pretty much equal in their reliability records, overall. The horror stories on each are what you hear and get repeated. Go to the tracks and talk to people on each bike that have had them for a time and have no interest in inflating its worth and see what prople have problems with. Then make a decision. I have discovered that if I read a lot of threads at several websites without commenting I can get a feel for what is working. Open ears and eyes learn a lot.

Just a rambling post by an old rider and engineer. Back to our regularly scheduled programming.

Bill

[Macho393]

Better engine Yamaha.....better frame /suspension Honda. But if your not a AA rider(semi pro)/fast guy. That don't matter. By far less maintenance is the yamaha. Maintenance is plan and simple the up keep of the bike what ever it takes. That being said I've run both of them into the dirt. But the Yamaha lasted longer. I ride woods also, thats the wrost you can treat a bike(2-3 hour races)

[pdmoyes]

Okay, here's an update guys. My cousin, the one who's been raving about Honda's reliability, just took his new 05 450 out to the Glamis dunes. Long story short, blew up... you guessed it, the valve train. I've spared the "I told you so" for now. He's looking at a big $ outlay.

[Woody_393]

Yeah he is... that blows. How was he as far as maintenance? Did he think the bike was an XR or did he maintain it well?

[pdmoyes]

Yeah, he was very good on maintainance, that's why he said there was no problem with Honda's...he'd never had a problem with any. This bike was brand new to him. Its was a very well known supercross and certain magazine test rider's bike that he had just bought. I feel bad for him now though.

[Keetoman393]

Originally Posted by pdmoyes

Its was a very well known supercross and certain magazine test rider's bike that he had just bought.

In other words, it had been bounced off the rev limiter countless number of times. Sorry to hear about your buddy's bike. It's a real bummer to know how much you are going to have to spend when something lets go.

[Woody_393]

Ahh, that really does blow

[pdmoyes]

So who can help me diagnose what actually happened. He said it was a little harder to start as the day went on, and then when he was in the deepest bowl of the dunes, he was heading out of the bowl hard and fast (but not anywhere near the rev limiter) and heard a pop sound. When you got to the top of the dune, he headed back down into it and heard a pop again and then it died, never to start again.

I don't have a whole lot of experience with these bikes yet, anyone want to throw their opinion in?

[Faded]

Originally Posted by pdmoyes

So who can help me diagnose what actually happened...anyone want to throw their opinion in?

What broke...you never really said, but you hinted at 'valve train'...

Originally Posted by Faded

The stock intake valves are two piece units made of Titanium that are welded where the valve stem meets the valve head. Titanium has a tendency to become elastic and stretch before it breaks so when you see your valve clearance require a shim size 3 sizes smaller (or more) to get valve clearance back in spec it’s time to seriously start looking into getting your head checked. Otherwise the alternative could possibly be broken intake valves and the excessive damage that comes with it.

03 CRF450 Maintenance

Life Expectancy of Titanium Valves