Powerband very different after minor mechanical work

[dannymax]

I've had my '05 (31K) since March and only put about 1500 miles on it so far. The power of this machine impressed me right from the first twist of the throttle. I also have a stock '99 V Max which is pretty quick, dyno's at 117.1 hp @ 80 ft. lbs. of torque and I felt the 'Feej' would certainly hang with the Max or even pull it through the gears.

I took the FJR to the shop last week to have: valve check and adjust (if needed), upgraded CCT installed, TB sync, new plugs, compression check and air cleaner checked and replaced if necessary.

The valves were right in the middle of the tolerance range, TB's required minor tweaks on two of them only, compression was 215#, 215#, 205# & 210#, air cleaner was blown out and re-installed.

The shop owner took the bike out for a test drive and said it runs great but doesn't quite have the roll-on power of a V Max....I found that a little puzzling.

The first ride after the shop work showed me what he was talking about, using a 60 mph, 5th gear roll-on....at about 1/4 throttle it pulls good (about like it did before) but any more throttle and the power falls off noticeably. If I whack it WOT at 60 it will slowly accelerate but not remotely like it did before taking it to the shop.

I know nothing about this motor but it doesn't seem like any work performed at the shop could result in this drastic a change in power delivery.

Does anyone have any ideas what may have caused this or what I can do to get my power back?

 

[FJRay]

I would suspect when the CCT was installed the cam timing moved. If the tech doesn't secure the chain before releasing tension it can change pretty easy.

 

[dannymax]

I talked to him on the phone Friday and he mentioned said they took measures to insure that didn't happen (I don't remember exactly what he said though).

Is there a way for me to check that without going way in the motor?

 

[Peter Murray]

I talked to him on the phone Friday and he mentioned said they took measures to insure that didn't happen (I don't remember exactly what he said though).

Is there a way for me to check that without going way in the motor?

Short answer no... You have to pull the valve cover and R case to check alignment of the timing marks to be sure.

A improper TB sync can make the bike sluggish or bog as described by the roll on test vs WFO.

 

[dannymax]

Thanks guys, not much choice here....time to strip the plastic off and trailer it back.

They can check everything and sort it out.

 

[ionbeam]

Long shot #1 is restricted air intake. Failure to pull at larger throttle openings can be caused by poor air flow and the dealer did diddle with the air filter and intake track. This is a symptom of a really plugged air filter.

Long shot #2 is one or more plugs not getting full power. There are several ways to screw up the plugs beginning with pulling on the plug wire and separating the wire at the cap. Next is failure to seat the cap fully on the plug or the cap popping back off the plug. If the plugs were iridium and someone checked the plug gap there is an excellent chance that the plug(s) got damaged. If it is damaged plug wires, they can be reattached to the cap.

Long shot #3 is the possibility of a pinched fuel hose.

Failing this, it is time to look at the cam gears for alignment marks.

 

[dannymax]

Long shot #1 is restricted air intake. Failure to pull at larger throttle openings can be caused by poor air flow and the dealer did diddle with the air filter and intake track. This is a symptom of a really plugged air filter.

Long shot #2 is one or more plugs not getting full power. There are several ways to screw up the plugs beginning with pulling on the plug wire and separating the wire at the cap. Next is failure to seat the cap fully on the plug or the cap popping back off the plug. If the plugs were iridium and someone checked the plug gap there is an excellent chance that the plug(s) got damaged. If it is damaged plug wires, they can be reattached to the cap.

Long shot #3 is the possibility of a pinched fuel hose.

Failing this, it is time to look at the cam gears for alignment marks.

I wondered about the air intake track....do these bikes have a mass airflow sensor, and could it have gotten messed up when they diddled with the air filter?

They said the filter was very clean and there was no need to replace it.

Wouldn't the plug wires and pinched fuel line show up all the time if they were buggered up?

The bike seems to pull strong in the lower gears, no missing or faltering. Whether it's as strong as before, it's hard for me to tell.

 

[BkrK12]

Long shot #1 is restricted air intake. Failure to pull at larger throttle openings can be caused by poor air flow and the dealer did diddle with the air filter and intake track. This is a symptom of a really plugged air filter.

I have tried on several occasions to blow out what appeared to be a reasonably clean air filter with not good results. In every instance, I suffered performance degradation like you're talking about. Putting a new filter in worked every time. Now I just replace the filter. You might try that before having your bike disappear into the dealer black hole for a couple of weeks.

 

[olsonm3915]

I'll bet anything it's the timing. When I replaced my CCT I was so confident I had tied the timing chain tightly with a cable tie that I didn't even check after changing it out, to see if the timing was right. That was a mistake. The bike started and ran OK but when it warmed up it wouldn't idle. I kept telling myself there was no way the timing chain had slipped, but after checking everything else under the sun, I figured I'd waste a little time and check it even though I *knew* it wasn't going to be off. Well, it was. Check it.

 

[ionbeam]

I wondered about the air intake track....do these bikes have a mass airflow sensor...They said the filter was very clean and there was no need to replace it...Wouldn't the plug wires and pinched fuel line show up all the time if they were buggered up?

There is a very good likelihood that the cam timing is off, but it isn't the only suspect. I offered some low to no cost things to check first.

There is no MAF. Blowing out the filter is per the Factory Service Manual, but there is still a chance to compact the filter material and restrict air flow. Washing the filter is a sure way to kill the air flow due to compacting the fibers. If the shop air supply doesn't have a water/oil trap they could have inadvertently 'hosed' your filter. There may also be assembly errors when putting the intake back together... Yamaha could have made the air intake easier to access and work on.

It is possible to have one or more plugs with connection problems and still have the engine run acceptably under low demand situations. There would be a spark gap at the point of disconnect; if it is a narrow gap the spark will jump that gap and jump the gap at the plug too. The FJR uses a waste spark system so one plug being weak would actually affect two cylinders. At low rpm there would be sufficient energy to fire the two cylinders but as engine load and rpm's climb it would not have enough energy for good combustion. This situation is less likely but can't be ignored. One indirect way to check for this is to measure header pipe temperature after running the engine at the power-loss rpm level.

A pinched fuel line can supply sufficient fuel flow for low rpm operation but be unable to supply sufficient fuel flow under higher demand.

It sure would suck to take the cam chain cover and intake cover off only to discover that the problem was someplace else that could have been easily checked first.

 

[dannymax]

I have tried on several occasions to blow out what appeared to be a reasonably clean air filter with not good results. In every instance, I suffered performance degradation like you're talking about. Putting a new filter in worked every time. Now I just replace the filter. You might try that before having your bike disappear into the dealer black hole for a couple of weeks.

I sure would like to avoid that 'black hole' if at all possible....air filter replacement is easy to do and not costly at all.

Step #2, if the filter doesn't do it, will be to read my service manual and build up some confidence in checking the cam timing.

 

[Bungie]

I'm with Alan on this one. Check for a pinched fuel line first. Things get a little tight under the tank and it's really easy to pinch one off. (er...)

 

[charismaticmegafauna]

I've had my '05 (31K) since March and only put about 1500 miles on it so far. The power of this machine impressed me right from the first twist of the throttle. I also have a stock '99 V Max which is pretty quick, dyno's at 117.1 hp @ 80 ft. lbs. of torque and I felt the 'Feej' would certainly hang with the Max or even pull it through the gears.

Get another rider and race the two -- heads-up.

The results will be readily apparent...

The shop owner took the bike out for a test drive and said it runs great but doesn't quite have the roll-on power of a V Max....I found that a little puzzling. The first ride after the shop work showed me what he was talking about, using a 60 mph, 5th gear roll-on....at about 1/4 throttle it pulls good (about like it did before) but any more throttle and the power falls off noticeably. If I whack it WOT at 60 it will slowly accelerate but not remotely like it did before taking it to the shop.

I know nothing about this motor but it doesn't seem like any work performed at the shop could result in this drastic a change in power delivery.

Does anyone have any ideas what may have caused this or what I can do to get my power back?

Peformance degradation (or improvement) may be hard to tell via the 'butt dyno'...

Dynomometers, stop watches, and speedometers work well for that...

Your FJR, if running well, will walk right up to 150 MPH (w/very little effort)...

Will it?

 

[FJReady]

My vote is that the cam chain jumped a tooth on the crank. this happened to mine when CCT was replaced. Very obvious to me with respect to throttle response. It felt like it was starved for fuel. It would start and idle OK but felt like 2/3 power when trying to accelerate. resetting of the cam chain timing put things back in order.

 

[dannymax]

Your FJR, if running well, will walk right up to 150 MPH (w/very little effort)...

Will it?

It pulls good at 1/4 throttle but falls off if any more throttle is applied.

Or put differently, if I whack it WOT it will sluggishly accelerate and when I roll back out of it there is a noticeable power surge as throttle passes back down through the 1/4 opening position.

If that makes any sense.

 

[charismaticmegafauna]

It pulls good at 1/4 throttle but falls off if any more throttle is applied.Or put differently, if I whack it WOT it will sluggishly accelerate and when I roll back out of it there is a noticeable power surge as throttle passes back down through the 1/4 opening position.

If that makes any sense.

Sounds-like -- you only have enough fuel available for (up to) 1/4 throttle?

Does your FJR idle properly -- 1K ~ 1100 RPM?

 

[dannymax]

It pulls good at 1/4 throttle but falls off if any more throttle is applied.Or put differently, if I whack it WOT it will sluggishly accelerate and when I roll back out of it there is a noticeable power surge as throttle passes back down through the 1/4 opening position.

If that makes any sense.

Sounds-like -- you only have enough fuel available for (up to) 1/4 throttle?

Does your FJR idle properly -- 1K ~ 1100 RPM?

It appears to idle smoothly @ 1K, same as it did prior to going in the shop.

I just took a look under the tank, didn't see where anyone had 'pinched one off' but possibly it unpinched when I raised the tank.

So I'm going to take it for a short ride, maybe get better info????

 

[dannymax]

If I keep the throttle in the first 1/8 - 1/4 the bike has pretty decent acceleration, whacking it WOT and the power drops off, it's still picking up but not as strong.

Would cam timing act like this or would that show as a lack of power with all throttle openings?

The 'ass dyno' is getting confused, and there are POlice all over the place out there....best bet is to put her on the dyno this week, see what the curve says and go from there.

Almost forgot, there was a pretty strong gas smell when I pulled in the garage after the last ride. I have noticed a slight gas odor before, this seemed a little stronger.

Is it not too unusual with the FJR to have a little gas odor?

 

[FJReady]

What you're describing is just what I felt after my CCT replacement. I got $10 that says your cam chain timing is off. The clue is first sentence in post #18 Whacking the throttle anywhere above 2K and the FJR should take off like a scalded dog.

I know its not fun to think about having to get your wrench to go back to fix his probable (very likely) mistake but I think you have to do it.