Yamaha Wolverine Forum banner

1 - 14 of 14 Posts

·
Registered
2017 Yamaha Wolverine R-Spec SE, 2” Perfex Lift, 27” Maxxis Bighorns
Joined
·
10 Posts
Discussion Starter · #1 ·
Valve clearance question.

I have a 2017 Yamaha Wolverine SE 708 with 4,700 miles on it. It has been maintained at all service intervals.
I am checking the valve clearance as a regular maintenance interval. The machine does stall when cold every once in a while, but not every time. No running issues when at operating temperature. Cranks up good, except when it stalls, then hard to start, but it will start back up and run ok. Oil pressure good, temperature good, performed cylinder leak down test with OTC leak down gauges. It will hold both gauges at 80 psi with 0 leak down when at TDC.

I have a service manual, and I am mechanically inclined. I lined up all of the timing marks correctly on the cam gears and the crankshaft for TDC. I checked the valve clearance, and the exhaust valve closest to the cam gear is at .001in clearance. The spec for the exhaust valves is .0087-.0126in. The other exhaust valve was in spec at .009in clearance. Both intake valves were in spec at .004in and .005in clearance. I removed the lifter from the exhaust valve that the valve clearance was not in spec, and the shim is 1.60mm or .06299in. To get the correct clearance I need a 1.35mm or .0531in shim, but the smallest shim that Yamaha offers is 1.45mm or .05709in. Do I have a valve issue, or is there any way to get a smaller shim other than the 1.45mm or .05709in?
 

·
Registered
2022 RMAX2 1000 XT-R
Joined
·
204 Posts
If it's a two cylinder, you may have to rotate the crank shaft xxx amount of degrees to measure valve clearance on the 2nd cylinder. Just make sure the cam shaft is installed first. ;) There is a TDC for each cylinder.
 

·
Registered
2017 Yamaha Wolverine R-Spec SE, 2” Perfex Lift, 27” Maxxis Bighorns
Joined
·
10 Posts
Discussion Starter · #3 ·
If it's a two cylinder, you may have to rotate the crank shaft xxx amount of degrees to measure valve clearance on the 2nd cylinder. Just make sure the cam shaft is installed first. ;) There is a TDC for each cylinder.
It is a single cylinder 708cc.
 
  • Like
Reactions: DirtRoadWarrior

·
Registered
2017 Yamaha Wolverine R-Spec SE, 2” Perfex Lift, 27” Maxxis Bighorns
Joined
·
10 Posts
Discussion Starter · #4 ·
I was able to find a valve shim kit from Hot Cams that goes down to 1.20mm shims. The stock Yamaha shims are 9.4615mm in diameter and the Hot Cams shims are supposed to be 9.48mm in diameter, so I am hoping they will fit with no issue.
 

·
Registered
Joined
·
1,751 Posts
I used Hot Cams for mine...got some from the Yamaha dealer who was kind enough to show me them (5 for the price of 1 OEM) and then ordered some others off Amazon. The 9.48 are the standard size IIRC. If the Hot cams are a little big for the recess in the retainer just file the edge a little. Yes, you may have a valve issue with that much change and that many miles...... maybe as a check see what the shim is in the other exhaust valve for comparison and guess at where it started.
 
  • Like
Reactions: kehendges

·
Registered
2017 Yamaha Wolverine R-Spec SE, 2” Perfex Lift, 27” Maxxis Bighorns
Joined
·
10 Posts
Discussion Starter · #6 ·
I used Hot Cams for mine...got some from the Yamaha dealer who was kind enough to show me them (5 for the price of 1 OEM) and then ordered some others off Amazon. The 9.48 are the standard size IIRC. If the Hot cams are a little big for the recess in the retainer just file the edge a little. Yes, you may have a valve issue with that much change and that many miles...... maybe as a check see what the shim is in the other exhaust valve for comparison and guess at where it started.
Thank you jimclemjr for the response. The stock shim size in both exhaust valves was a 1.60mm.
 

·
Registered
Joined
·
1,751 Posts
Well that would make me feel a little better .... but I would change them both to get to far end of range open. As long as I was in there.
 
  • Like
Reactions: kehendges

·
Registered
Joined
·
1,751 Posts
'Hard' is relative...... not really hard imho but for some impossible without a high degree of stress. It would take a set of gaskets and 4 new head bolts. New fluids. Cams out. Remove exhaust pipe and intake/throttle body system. Probably want to get a new piston pin clip as well. Couple hours you could be looking at the valves. Few more hours going back together with piston/cylinder install, then get TTY (torque to yield) head bolts done and then cams back and timed. valve clearances checked and reverified after head torqued.
Some would disassembly and reassembly piston and rings and cylinder back the way they took it apart, depending on cylinder/piston wall condition.
 
  • Like
Reactions: DirtRoadWarrior

·
Registered
2022 RMAX2 1000 XT-R
Joined
·
204 Posts
'Hard' is relative...... not really hard imho but for some impossible without a high degree of stress. It would take a set of gaskets and 4 new head bolts. New fluids. Cams out. Remove exhaust pipe and intake/throttle body system. Probably want to get a new piston pin clip as well. Couple hours you could be looking at the valves. Few more hours going back together with piston/cylinder install, then get TTY (torque to yield) head bolts done and then cams back and timed. valve clearances checked and reverified after head torqued.
Some would disassembly and reassembly piston and rings and cylinder back the way they took it apart, depending on cylinder/piston wall condition.
Not much more work for a 708 top end rework. Good to go for another 5k. I did it on a XR600 air cooled motor about that time (5k miles). Not sure how these liquid cooled motors are good for under normal conditions.
Now, the Rmax 1000 top end rework looks a lot harder. Appears you gotta split the case. Yikes!
 

·
Registered
2017 Yamaha Wolverine R-Spec SE, 2” Perfex Lift, 27” Maxxis Bighorns
Joined
·
10 Posts
Discussion Starter · #11 ·
Water cooled engines have much lower cylinder head temperatures than air cooled cylinder heads.
My plan right now is to shim all of the valves as close to the high end of the specs as possible at .0126in for the Exhaust and .0079in for the Intake to allow for some future valve wear. I performed a Cylinder leak down test at TDC and the cylinder held at 80psi with 80 psi input pressure with no leakage. I feel good about the health of the cylinder at this moment, and it also runs great. I don’t plan on tearing the top end of the engine down over .010”-.011” of valve clearance. Could there possibly be a valve issue, yes that is possible, but there is not enough evidence for me to tear into the top end of the engine. It might have a valve failure in the future, but it might also run 5,000-8,000 more miles. Right, wrong, or indifferent that is my plan as of now.
 

·
Registered
Joined
·
1,751 Posts
I believe it would also help your service life if you would work on modifying the lean burn issues. Things like the air injection system plug or removal, and the re-flash of ECU. I have noticed a significant lessening of heat off muffler and pipe after adding the PCV and AFR gauge, so anticipate that actual cylinder temps are lower.
BTW not a bad time to replace the valve seals, $20 +/-. When I pulled my springs I discovered that the factory left out the spring seats... order a couple extra keepers in case you need them only a few dollars.
 

·
Registered
2017 Yamaha Wolverine R-Spec SE, 2” Perfex Lift, 27” Maxxis Bighorns
Joined
·
10 Posts
Discussion Starter · #13 ·
I did the AIS block off already. After I finish my current clutch upgrades with wet clutch slug kit, 18gr weights, milled primary sheave, purple secondary spring, and clutch seals, I am planning on addressing the air fuel ratio issue next. Did you upgrade your exhaust system or is it stock?
 

·
Registered
Joined
·
1,751 Posts
Yes and No. Left factory system. I did not want to spend $500 or so for a claimed 1 or 2 HP. And IIRC those gains are typically at WOT. I ride trails and find I wanted the initial torque at lower/mid rpms. So have kept the factory muffler with the designed back pressure. Initially I cut off the pee tube as it felt embarrassingly small and shaped lol. I welded a 2 1/4" sliced auto exhaust tip onto the outside of the spark arrestor case and it provide a much improved look and enough of a sound change to avoid the piff, piff noise and little dust clouds off the ground. Next, I played with taking the outlet pipe out of the spark arrestor and found that the back pressure dropped tremendously (more lean), so added back a 1" pipe in the arrestor and calculated the volume (+22%) so the flow was improved. I only did that after I got my AFR gauge and PCV so I could map the curve I needed. I also have not messed with the muffler/cat core. Basically it is a factor that I did not want to increase the volume to lose anymore hearing or get anymore crickets than my old ears already have. I further wanted to keep the spark arrestor intact, as I believe that is a basic responsibility we have and with the droughts being experienced in the last decade or two a single spark could have major impact to the environment (no soapbox just my factor- but hope you feel the same lol). Probably a factor that while doing the internals I have deshrouded the valve ports. Note in my sig the other motor changes I have made- see how that signature helps :)
 
  • Like
Reactions: Friskydingo
1 - 14 of 14 Posts
Top