Valve Adjustment - Lessons Learned, Observations, and Tips

[JJ_08 9]

I just wanted to share a few tips and lessons learned based on my experience adjusting my valves last weekend.

First of all, I want to thank Pursuvant and noodles for your excellent How-To's -- thanks for the time and effort you put into those writeups!

Draining the Radiator
Some of you may be wondering, like I was, whether its possible to check your valves without draining the coolant and removing the radiator. While it may be possible, it's probably not worth it. There's not a lot of room to work in there. I highly advise anyone doing this job to invest the effort up front to drain the coolant, fully remove the radiator, clutch cable bracket on the right side of the frame near the radiator, and disconnect any electrical connectors required to relocate as much of the wiring harness out of the way as possible. It's well worth the effort. 

Valve Cover Woes
The actual valve clearance inspection and adjustment was pretty straightforward, but I ended up spending way too much time trying to maneuver the darn valve cover and gasket back in place. After numerous failed attempts, I found that it was impossible to line up the gasket with the spark plug holes without first "gluing" the gasket to the valve cover (I used Permatex - Yamabond, Hondabond or just about any gasket maker will work).

Legit Service Interval?/Warning Signs
With 13,000 miles on the clock, I discovered that the two right exhaust valves were concerningly tight (0.15). The two left exhaust valves were at the lower limit (0.25). All of the intake valves were approaching the lower limit (0.13). To be fair, I suspect that my bike was not exactly lovingly cared for by its previous owner, but I was still pretty surprised to see the clearances this tight on a bike that's only half way to the service interval of 26,600 miles.

The reason I decided to check my valves was because I noticed my gas mileage was terrible (35 mpg on average). I'd also noticed that the bike would start on the 1st or 2nd crank when cold, but I'd have to crank and crank with the throttle cracked open whenever the engine was hot.

All of that is to say - I'm a tiny bit skeptical of Yamaha's claimed 26,600 mi valve service interval. I'm glad I checked mine when I did.  If you've noticed your fuel economy is in the dumps, if your bike is having trouble starting, if it's running rough, or if you generally like to hang out on your rev limiter, you might want to check your valves even if you're not at the service interval yet. 

[00RAH 82]

Just now, JJ_08 said:

I just wanted to share a few tips and lessons learned based on my experience adjusting my valves last weekend.

Draining the Radiator
While it may be possible, it's probably not worth it. There's not a lot of room to work in there.

Valve Cover Woes

I ended up spending way too much time trying to maneuver.
 After numerous failed attempts, I found that it was impossible.

Legit Service Interval?/Warning Signs

I suspect that my bike was not exactly lovingly cared for by its previous owner.

The reason I decided to check my valves was because I'm a tiny bit skeptical of Yamaha's.

You might want to check your valves even if you're not at the service interval yet.

 

Edited August 18, 2022 by 00RAH

[Triple Jim 476]

@JJ_08  did your fuel economy go back to where it should be, and starts get easy after the adjustment?

[Pursuvant 427]

@JJ_08  You can help me by marking up everything you don't like in "How To". Be critical and say it like it is. Add it to this post, I'll make the edits.

Here's the howto

[JJ_08 9]

@Triple Jim

Starting has definitely improved!  The hot start hesitation has gone away, and cold starts are easier (I don't have to hold down the starter as long before the engine catches).

The jury is still out on fuel economy - I've only put a few miles on since I got the motor back together, so I'll have to report back.  But based on the few miles so far...  it looks like the source of the problem may largely be in my right wrist. 

 

@Pursuvant

I have nothing but praise for your How To!!  Any time I'm working on valves, there's always a moment when I've got everything back together, but there's 5% of my brain that still wonders whether I got the timing right, and worries that I'm about to crash a valve into a piston as I turn the engine over.  I turned to your guide to check and double check my work, and it gave me confidence that I wasn't going to blow up my motor upon startup.    I especially appreciate that you included a count of the links on the cam chain between the intake and exhaust sprockets!  Thanks again for the effort you put into the writeup!

Edited August 19, 2022 by JJ_08

[Triple Jim 476]

Just now, JJ_08 said:

Starting has definitely improved!  The hot start hesitation has gone away, and cold starts are easier (I don't have to hold down the starter as long before the engine catches).

When I got my Ninja 250 it had about 15,000 miles on it.  It was hard to start when cold, and when it did start it wanted to either run at about 400 RPM or 4,000 RPM.  When it warmed up it was fine.  After a valve adjustment to open up all the clearances, it started and ran fine.  That engine opens valve clearances as it warms up.  From your description, the MT closes them as it warms. 

[JJ_08 9]

On 8/18/2022 at 1:40 PM, Triple Jim said:

@JJ_08  did your fuel economy go back to where it should be, and starts get easy after the adjustment?

For anyone who was curious - after several tanks of gas, I can report that, unfortunately, my fuel economy has not improved.  I'm still averaging <40 MPG.  I'm coming to the conclusion that root of my problem may lie primarily in my right wrist.  

90% of my riding is recreational, on my favorite twisty roads, and apparently, that type of riding is not conducive to good gas mileage.  When I'm doing regular, around town and freeway riding, I see my instantaneous gas mileage goes up to the 40's-50's, but in the twisties where I spend most of my time, my mileage is usually floating around the 20s-30s.    Curious if others who do mostly "spirited" riding are getting better gas mileage?

[Triple Jim 476]

I've never gotten below the upper 50s for average MPG no matter how I've ridden, but my ECU map is stock.  Last spring when I was out in the western NC mountains for a week, there were a couple days when I rode nothing but small twisty back roads.  The speed limits, as well as maximum practical speed was 45 for most of those days.  I averaged 72 MPG.  I've checked that displayed MPG against pump gallons and GPS miles, too.

[JJ_08 9]

4 hours ago, Triple Jim said:

I've never gotten below the upper 50s for average MPG no matter how I've ridden, but my ECU map is stock.  Last spring when I was out in the western NC mountains for a week, there were a couple days when I rode nothing but small twisty back roads.  The speed limits, as well as maximum practical speed was 45 for most of those days.  I averaged 72 MPG.  I've checked that displayed MPG against pump gallons and GPS miles, too.

YIKES!

It sounds like something is off with my bike...  I bought it from a questionable seller, and I would not be surprised in the least if something is wrong with it...  the question is what?  I've adjusted valves, cleaned and sync'd throttle bodies, and changed plugs...   ECU appears to be stock (maybe it's flashed? But I doubt it...).  Hmm.  I might start a new thread for this so as not to get too far off topic on this thread.

Thanks for the info @Triple Jim!

[Triple Jim 476]

It might be worth running through a tank with conservative throttling.  Like try to keep the "ECO" lit most of the time, just to see what average MPG you get as a best case.  If you're not happy with that, then you could start looking into how the ECU is programmed.

[shinyribs 1,663]

Are you running a stock air filter or something else? 

 

I know of two other 07's ( first gen bikes, if it matters) that had their valves checked on schedule and by 75,000 miles still did not require any adjusting. I checked mine around 30,000 miles and they were fine. Just put the cover back on. 

The only thing that can cause premature valve wear is dirty air , so I'd inspect the intake tract carefully. Check the filter for tears and that it's seated properly. Dab of grease n the sealing lip is a good idea. Make sure all the throttle body boots are also seated well. 

If it's an aftermarket gauze type filter it could be in need of servicing. Once they dry out, or the oil in the gauze catches what dust it can, any other dust that comes along will go right through the filter. It has to be clean and sticky for dust to cling to the filter and not enter the engine. 

[JJ_08 9]

On 1/1/2023 at 1:50 PM, shinyribs said:

Are you running a stock air filter or something else? 

The only thing that can cause premature valve wear is dirty air , so I'd inspect the intake tract carefully. Check the filter for tears and that it's seated properly. Dab of grease n the sealing lip is a good idea. Make sure all the throttle body boots are also seated well. 

It's had a stock airbox and OEM filter as long as I've had the bike, but I don't know if the previous owner may have swapped them out at some point.

I suspect that the bike was flogged by its previous owner - the tires had the telltale look of track use when I got the bike, and it'd been crashed at some point.  I wouldn't be surprised if my bike had spent a fair amount of time bouncing off the rev limiter in it's previous life, which, I'd imagine, also accelerates valve wear.

[shinyribs 1,663]

I don't know. I'm very hard on tires, crash my bikes and absolutely love that rev limiters exist. I never have engine problems, but I also only ride Yamaha and Honda sport bikes.

I know I nipped the rev limiter of my 07 several times during the break in period  

Good oil, clean air and let her rip!