Rich and rough engine woes -- 2001 (03 US) Gen 1

I was just playing with my TBS and noticed that no matter how hard I try I cant get the vacuum reading to get above 16cmHg while staying in balance. I've been having problems with my idle performance since I bought the bike. It likes to wander by about 500rpm even when warm and stays there for awhile. It's almost like cold starts but after the fan is already running. If I set the idle above 1000 rpm the engine starts to hang on the way back to idle. I can't seem to find a vacuum leak either. I've tried using ether mist and torch gas (more of a fog coming out but I can't remember what it's made of) with no increase in rpm.

It needed a lot of work when I got it home and I don't remember how it ran before purchase. One of the things I did was a valve adjustment. I felt pretty confident that it was done correctly in part because I didn't remove the chain from the cams. The only valves out of spec were intakes so I never touched the exhaust cam. If I did get the intake came out of sorts, would it cause poor vacuum?

My engine problems list looks like this. What, if any, of these could be related

-Wandering idle

-Low vacuum reading

-Runs very rich but plugs look fine. (Set the CO level based on this. 2 and 4 were a little darker so set it to 12-11-12-11)

-I have no idea what mileage I should be getting but if I remember right its been getting at least upper 30s to low 40s MPG. Still enough to make it ~240mi on the highway.

-There is a definite hesitation in the throttle coming off a stop or trying to do slow turns with the engine below 2k. Getting going I can crack the throttle a little bit and the engine will hesitate, and without winding any more throttle in, the engine will then surge to acceptable speeds. This actually makes me leery of tight turns in towns.

-And lastly there is a sort of gear crunching sound from the bottom of the engine if I rev from idle with even moderate gas. It sounds almost like crunching a gear change in a slow moving car. I have a sound file but the quality is poor and I don't know how to post it.

On a brighter note, I found the source of the petroleum smelling smoke rising from under the right side of the gas tank. At some point long ago, someone forgot to replace the crank case breather on the air box and left it jammed under the intake boots.

sath182 said:

I was just playing with my TBS and noticed that no matter how hard I try I cant get the vacuum reading to get above 16cmHg while staying in balance.

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Ignore the absolute vacuum readings and just make them all the same.

sath182 said:

I've been having problems with my idle performance since I bought the bike. It likes to wander by about 500rpm even when warm and stays there for awhile. It's almost like cold starts but after the fan is already running. If I set the idle above 1000 rpm the engine starts to hang on the way back to idle. I can't seem to find a vacuum leak either. I've tried using ether mist and torch gas (more of a fog coming out but I can't remember what it's made of) with no increase in rpm.

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RPM wanders by 500? No, not normal. Wandering by about 50 is normal.

sath182 said:

It needed a lot of work when I got it home and I don't remember how it ran before purchase. One of the things I did was a valve adjustment. I felt pretty confident that it was done correctly in part because I didn't remove the chain from the cams. The only valves out of spec were intakes so I never touched the exhaust cam. If I did get the intake came out of sorts, would it cause poor vacuum?

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Even if you keep the chain tied to the cams, the chain can, and usually will, skip a tooth on the crankshaft sprocket when you slacken the tensioner unless you take precautions to also ty-wrap the chain down there. This does cause idle problems as the valve timing is further advanced. What that does to vacuum? Dunno.

sath182 said:

My engine problems list looks like this. What, if any, of these could be related-Wandering idle (50 rpm wandering is normal)

-Low vacuum reading (ignore the vacuum level)

-Runs very rich but plugs look fine. (Set the CO level based on this. 2 and 4 were a little darker so set it to 12-11-12-11)

-I have no idea what mileage I should be getting but if I remember right its been getting at least upper 30s to low 40s MPG. Still enough to make it ~240mi on the highway. (this sounds completely normal for a 1st gen)

-There is a definite hesitation in the throttle coming off a stop or trying to do slow turns with the engine below 2k. Getting going I can crack the throttle a little bit and the engine will hesitate, and without winding any more throttle in, the engine will then surge to acceptable speeds. This actually makes me leery of tight turns in towns. (this is also completely normal. You are running the engine at too low an rpm)

-And lastly there is a sort of gear crunching sound from the bottom of the engine if I rev from idle with even moderate gas. It sounds almost like crunching a gear change in a slow moving car. I have a sound file but the quality is poor and I don't know how to post it. (this is what is generally known as "lugging" the engine. Do not try and accelerate from 2k rpm. Keep your rpms at 3k or above, if really wanting to accelerate, way above)

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My comments intertwined above. Many a new FJR owner has made similar observations to yours when they initially try to lug it around like an old Harley Davidson. It's not. It's a modern 4 cylinder, relatively high rev-ing engine with fixed valve timing that likes to be run between 3000 rpm and redline.

If the idle really is wandering 500 rpm that is a ton. Yes you have a problem. But of it's really just 50 rpm or so, then your description doesn't sound all that alarming.

That's just the thing, I'm not running it that low unless I am pulling away from a stop light. If you say the hesitation is normal I can live with that. But, the lugging clunky sound is immediately off idle. If I give it a healthy rap, the clunkyness is the first thing it does as it picks up RPM. Is that cause I'm forced to have such a low idle to avoid my hanging issue?

If that's the case, any suggestions about the wander and hanging on the closed throttle decel? The hang has been bad enough on occasion that it will not drop below 1800-2000 without dragging the clutch. When this happens it seems to have a threshold when it drops normally but accelerating back through it induces the hang again. It is rare though and doesn't seem to be engine or air temp related.

That kind of hanging is indicative of a big vacuum leak.

Is the idle wandering 50 rpm or 500? 500 is bad.

If the valve timing were advanced one tooth from when you did the valve adjust, it might explain all of your symptoms.

How long has the go juice been in the tank ?? How many rats are in the air filter ?

How many miles on the bike/ camchain??

Too anxious on the post. I read your description of the "lugging" or grinding noise to be while revving in neutral, not on a pull in gear. Could this be cam chain noise?? Influence on idle rpm's?? I don't know.

I would love the cause to be a vacuum leak. Taking the valve cover off is a huge pain in the *** and there's no way I'm dropping the engine for it. The engine does both the normal wander and increases revs. King a like this,

____________________///////////////////////______________________///////////////////////////////////////////___________

There is no set rhythm it just changes the speed of where its idling at will. It's its the same change as coming off cold idle but backwards. Its not a 500 rpm flutter or quick surge. It behaves like turning the idle screw.

Bike has 65k. I bought it in August, fixed it up to October and been riding it off and on all winter. So, the gas is fresh and the air filter is too. As to if the sound is in neutral or under load, I need to double check, but I'm pretty sure its both. I really don't have a clue if the chain or cct are going bad. The engine seems to be more rattley that my SV.

Are there any sensors I should be checking? Is there a better way to check for a vacuum leak? Should I be looking some where other than just around the throttle bodies?

Well, if you don't have a vacuum leak then I have to agree with Fred and say the valve timing is the likely culprit. I know it is a pain to lift the valve cover, but it's much easier the second time and you will probably not need to replace any gaskets. Pull the valve cover and the timing chain cover and make sure the timing is correct for both cams. That's the only way you'll know for sure.

I suspect your mechanical timing is off by at least one tooth. The motor is surging because the ECU is attempting to correct for the valve timing being off. The ECU is doing so by adjusting the ignition timing and fuel trim.

There is no way that the ECU will succeed in making this engine run correct, but it is an incredible feat that it is able to keep the motor running. The mother ship knows what it is doing, it is keeping that motor running even when starting off without a mass airflow sensor.

It is a 2001 and I think the Cam Tensioner is unreliable at best. I do not think I would ride the bike until I verified that the mechanical timing is correct. No way around it, you are going to have to check it. For the money, I would put a blue dot tensioner on this bike as well.

Lube your relay arm. England is where a couple of guys have had the dog bones break.

I apologise ahead of time for the disjointed nature of my thoughts. I'm just trying to provide as much info as may be helpful. That and its bed time.

I tried once again to find a vacuum leak. Blocked off the intake and exhaust then rigged a bicycle pump to one of the vacuum ports started spraying soapy water aaaaaaaaaaaaaand... nothing. Tried again with ether and the tips unplugged (***** and giggles) and nothing. Giving a short puff into the intake would bog and stall the engine.

Also I played with the idle and with it resting just under 1000 I got it to re produce a hang at 1500 from blipping the throttle. It stayed there for about a minute and the settled on its own. Blipped again, and hung again. This was in neutral. But at this point I can adjust the idle back and limit the hang, or I can advance it and it idles at 1500. This is with only the smallest of movements on the idle screw. Could this be more of a symptom of the idle rest screws being off? Once in a while I can sit at a stop light and the idle will advance, but I couldn't reproduce it here in gear.

The engine does sound like its running well, just rich as hell. And the CCT is a blue dot. When I did the valves last time, it had a strong, snappy, full release. It is looking more and more like I need to crack the engine again. If I do I'm going full bore, buying a shim kit, and making sure all the valves are bang on. I actually think getting the coolant pipe back in is worse that getting the valve cover and gasket to behave. Speaking of valves, the bike starts on the 2nd or 3rd turn, not sure if that is supposed to be affected by bad timing.

As for the relay arm, it has a known bad bearing at the bottom of the shock. I just can't get the damned thing out to replace all the bearings. I think that one is going to turn into a dealer job.

Tip for getting the coolant pipe back in: Make sure the two holes in the head are nice and clean and use silicone grease on all three of the new o-rings.

sath182 said:

As for the relay arm, it has a known bad bearing at the bottom of the shock. I just can't get the damned thing out to replace all the bearings. I think that one is going to turn into a dealer job.

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If you can make it to deepest, darkest Norfolk I will be more than happy to help you sort out the relay arm.

Don

Donal said:

sath182 said:

As for the relay arm, it has a known bad bearing at the bottom of the shock. I just can't get the damned thing out to replace all the bearings. I think that one is going to turn into a dealer job.

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If you can make it to deepest, darkest Norfolk I will be more than happy to help you sort out the relay arm.

Don

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I will keep that in mind. You aren't far from Lakenheath and I've been there plenty of times. Just need to sort the bearings. But that's a different topic.

Did you look through this recent post? https://www.fjrforum.com/forum//index.php/topic/151599-gen-1-idle-issue-suggestions/

Not exactly the same symptoms as yours, but a few similarities.

Have you performed a TPS sensor check? https://www.fjrforum.com/forum//index.php/topic/3283-throttle-position-sensor/?do=findComment&comment=37996

Al.

Did you look through this recent post? https://www.fjrforum.com/forum//index.php/topic/151599-gen-1-idle-issue-suggestions/Not exactly the same symptoms as yours, but a few similarities.

Have you performed a TPS sensor check? https://www.fjrforum.com/forum//index.php/topic/3283-throttle-position-sensor/?do=findComment&comment=37996

Al.


I don't think i had seen that one, but it doesn't sound very close to my issue. For me, I have to be careful in slow speed turns because the engine will want to surge as certain sustained throttle openings. These are positions that are only used in slow, first gear maneuvers. Also, he actually has adjustment in his Idle from 1000 - 1500. With my bike it's one or the other. The problem doesn't seem to be as bad in gear, but it shouldn't even show up in neutral, anyway. I don't know if a Seafoam soak would help the idle. While I'd love to try it, but it's really expensive to get here. Also, I've run several different types of cleaners at higher concentrations over the last 6 months, so I don't know if it would help any. One of these was a whole bottle of Gumout something-or-other in a fresh tank, an over-night soak, and then a non-stop 190 mile trip down to one of the other bases.

I did do a TPS check with the first set of repairs, but I don't think the engine was hot. I will have to do this again. I can't imagine that there would be a fault at 2-5% throttle, given the history and symptoms I'm familier with for this issue.

Neither of these explain the enourmusly rich exhaust, either.

I'm putting together my parts list to do a more thorough valve and timing inspection. Looks like $58 before shims and shipping to get a new chain, new valve cover gasket, oil pump cover gasket, and orings for the coolant pipe. I'm not certain if I'm going to need the chain though. I figure I might tear it all down, check the timing, inspect the chain for stretch, check the valve lash again, and order the parts I need so I only pay shipping once. The joys of having two bikes, I can afford to have one broken down.

To Donal:

I was looking at bearings and such today as well. If I did get them and came for a visit, would the bearings in the swingarm be part of the picture?

Oh OK, they were just a couple of misc. ideas.

You don't say how many miles on your engine? I wonder if the injectors wear over time?

Keep us informed of your findings.

Al.

sath182 said:

To Donal:

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I was looking at bearings and such today as well. If I did get them and came for a visit, would the bearings in the swingarm be part of the picture?

We can do the swingarm if you think you need it? Is there any detectable movement now? The general consensus is these things are pretty rugged and shouldn't need too much attention, but if it makes you feel any happier we can have a look. The only bearing that (normally) gets any attention is the roller (needle) bearing on the left hand side, the ball bearing on the right is sealed and should be good for life!

@Donal, I meant the swing arm end of the dog bones. The only movement I have is up and down. Which is likely just from the bottom of the shock. But, since I haven't gotten the top off I don't know its condition. The way I see it, if I'm doing one, I'm gonna probably regret it if I don't do all of them. The swing arm pivot I don't know about either, I've not been able to get the u-joint off the output shaft, but that's also another story that I need a better T-50 and more torch gas to solve. This bike is THE poster child for all the preventative maintenance done around here. Not my fault at least.

Bike has 65k on it, I'm assuming the engine is original given the general state of it.