XJ650 just back from shop - better, but not when hot?

Hi All,

Just got my XJ650 (1981) back from the motorbike mechanic. The guy I put it in with is apparently an old bike fanatic and knew way more about my bike than I did (not hard, true)
Anyway, I had the cam chain replaced, valve clearances done, carbs cleaned, new spark plugs, rubbers repaired (couldn't find new ones), oil + filter, and synced. (Possibly more was done, but that's all I remember)
Long story short, the bike is running amazingly - especially for the first 1/2 hour of riding, but once I gets hot it starts to run a bit rough on low revs. Not rough enough that it's unrideable, but it's definitely missing under 3000 revs, but once I change gear down and get the revs back up to 3500 - it's absolutely unnoticeable! Virtually not there, just when the bike is hot and low revs - to clarify, getting off at lights is not an issue provided I give it a bit of juice.
(Also, I was too scared to do the carbs myself, so I'm going to trust that the mechanic knew what he was doing and ask that you grant he did a good job haha!)
And when I say that the engine is hot, the ride I did was 70km with a 3 minute break in the middle. Mostly highway at 100km/h. Was riding for roughly an hour straight.

So my question is this:
How are you supposed to ride the XJ650? Am I supposed to keep the revs at just about 3500ish revs, even if the engine sounds like it's running just a *little* bit high? When I stopped at lights, I had to keep pulsing the throttle, or it would stall, wouldn't idle. However, after I got it home and let it cool for 45 minutes, took it for a 6km ride and all the power was back in the bottom end, idled normally, could struggle along at 60km/h in 5th ok (2500rpm) and basically didn't seem to have any problems at all that it had when it was hot.
Am I being too easy in it trying to keep the rpm as low as possible? Will I hurt it if I keep the revs higher? On a slightly different note, even as the low end rpms were getting worse and rough - the high end (over 3500+) was getting sweeter and sweeter, could have driven on the highway and never noticed!
The bike has never been better, it was practically a different bike than the one I rode to the shop.

I'm just a little nervous as I have my first serious bike ride next Saturday, about 270km, and I really don't want to be leaving the bike 100km away. Everything else seems to be working really well and I love the bike, just wondering if anyone else has the problem with it running rough once it's warm? :lol:

Also, quick question - my speedometer and tachometer are 'bouncing'. the speedometer skips +/-5km around what I'm actually doing. Any guide on here to lubricating the speedo part that's attached to the wheel? It was making some funny noises a little while ago, but now it's constantly skipping. (And do not underestimate how little I know about motorbikes, if you need to say it like I'm stupid - better that I definitely understand you, than have to ask for the stupid answer anyway)
And my taco practically bleeds oil out of where it joins the engine and tries to set itself alight off the rightmost exhaust pipe :roll:

(Yamaha XJ650, 1981 - not sure about any other details other than that the mechanic said I have Hitachi carbs that apparently aren't too good on low revs)

 

Yamaha instruments: http://xjbikes.com/Forums/viewtopic/t=15303.html

Tach drive oil seals: http://xjbikes.com/Forums/viewtopic/t=19538.html

Your symptoms point to float levels that weren't adjusted properly;

or the shop lied and didn't actually adjust the valves. (That's also a symptom of tight valve clearances.)

These motors like to run at higher RPMs, true; but the thing about the Hitachis being "not too good at low revs" is pure balderdash. 100KpH is only 60mph; you should be able to ride ALL DAY at those speeds and the motor shouldn't misbehave at all.

The Hitachis don't work well if they're not properly serviced and accurately adjusted.

Honestly? It sounds like these folks immediately picked up on your self-professed lack of knowledge and had you on a bit; and didn't do as good of a job as you think.

 

Thanks for the links! That tacometer doesn't look too difficult (famous last words), I'll make a trip to Yamaha on Tuesday and pick up the o-rings to replace it. It's been driving me nuts, bike exhausts smoke up the oil on the air cooler and look like it's gonna catch fire.

100km/h is fine, bike would definitely have no problems at that speed - it's the lower speed, high gear stuff that I notice the miss. 60km/h at 2500rpm (5th gear) and I can hear the same sort of miss that it does when it idles. But if I gear down to 4th and kick the rpm over 3000, then it hums perfectly. I think I need to stop driving it like a grandma and give it a little stick now and then, especially when warm.

My brother got a Honda CBR250R that I test drove for him, and I honstly found it really, really hard as I've only ever driven a CBR250 and my XJ650 - both of which rev like a Corolla. But I think that's only when I'm riding. I've never had the rpm above 4500 and always sit in the highest possible gear that I can without the motor sounding like it's going to stall.

The speedo looks a little complex, also I'm pretty sure it's the unit down the bottom, not the gauge. A little while ago, I could hear a 'coughing' sound coming from the front wheel, which a motorbike mechanic said was most likely my speedo not being lubed inside, but I didn't have a look at it as I didn't want to open it and have springs flying past my ears and the bike forever parked unused because I'd broken it. I'll have a look in my service manual to see if they show it taken apart.

 

There's nothing to TAKE apart; the speedo drive unit is just that, a "unit."

It can be cleaned and lubed; your problem is more likely the CABLE.

The bike won't run well in top gear at 2500rpm, no. You should be able to "trickle" along, but it's not going to pull like it will with some RPMs on the clock. It should still be smooth though.

I'm still betting the shop didn't really do a lot of the things they said they did, because they realized you wouldn't know any better.

If I were you I'd at least re-check the valve clearances (not hard, you pop a couple of covers and need a feeler gauge) and start keeping track of fuel economy. If it's burning through way too much petrol, your float levels aren't right (which I also strongly suspect.) You might want to closely monitor the oil level as well, and sniff the oil filler opening occasionally for signs of gas in the oil (another symptom of misadjusted floats.)

The bike should run BETTER once warmed up fully; mine do. They missed or "fudged" something.

 

did they give you a breakdown of the parts they replaced? Ask for the list of what the shims numbers were before they checked them, what the clearances were, and what the new shims are that were installed. Let us know what they say.

Did they disassemble and clean the carbs, or did they just clean up the outside? HOW did they clean them?

Never heard that the "hitachi's are not good at low rev's" before. Baloney.

Replaced the cam chain? did he split the case? they are a link-less chain.

If it's running that rich, what are the mixture screw settings?

What's your oil leve? Check the sight glass. ALSO, pull the oil filler and smell the crank case. See if it smells like oil, or gas. If it smells like gas, you got float issues, too. If you don't see oil in the window, you have other issues. Sounds sort of like overheating issues........but could be other stuff..

Try a new set of plugs........if old plugs are in, the may just not be firing well til higher rpms throw a better spark. Check your plug caps while you're at it. Heck, check to make sure you're getting all the sparks at all the plugs from all coil leads at all times. It may turn out to be a simple electrical issue.

STay with us.........we'll eventually get you straightened out.

 

Hey Dave; per the factory books even, you replace the cam chain by breaking the chain and re-riveting the replacement; case-splitting not needed for that single-row chain.

Honestly, I'm suspicious of the whole thing. The cam timing might even be off by one tooth.

The Hitachi "claim" was the dead giveaway that something's not kosher.

 

My bike was given to the previous owner by somebody who had it sitting in a yard (not properly winterized) for 5 years. The owner fixed it up himself and used it as a work rider for 2 years, then sold it to me. I bought it because it was the cheapest bike on the market as a work rider $1500. So basically, when I took it in - it was the first the bike has seen any level of professionalism in about 9 years. The previous guy fixed a lot of things with tape and soldered screws across the fuse box...

I replaced the fuse box with a blade one and had the rear brake shoes replaced (completely delaminated) and re-did/checked all the terminations in the front lamp. Then it sat in my garage for 6 months unused because I changed jobs and got a free company car.

I got it out of the garage after sitting there and rode it to the mechanic and it was *rough*. Just all over clinking and clacking, wouldn't idle, couldn't get revs up, backfiring, everything.

I specifically asked if they could clean the carbs and do the valve clearances, as well as a general service. He said that he took the carbs completely apart and there was practically silt in my carb bowls - never looked at by previous owner. He said all of the jets were fine, bar one that's head had been destroyed, so he left it in the carb and cleaned it while it was still seated. He strikes me as trustworthy as he's just an employee of the shop.

He said they replaced the cam chain and did the valve clearances at the same time - he said that the jobs are pretty closely linked anyway, so they did it at once.

He definitely put new spark plugs in, I could tell they weren't the ones I put in a year ago, and told me that the thread on #1 plug had been practically ruined and to be very careful if I took it out as only the very end of the thread is left.

He wasn't able to find new rubbers (between carb and head), so he siliconed them up with heat resistant stuff. When I took it in, there were cracks big enough that you could see right into the chamber. The last guy had taped it with electrical tape, but not all of them.

The difference is incredible between before and after, fuel mileage has gone from 26mpg to 38mpg, so I'm pretty happy with that.

His comment regarding the carburettors went something along the lines that the Hitachi carbs weren't as good as other ones and that was the reason that they weren't used any more, saying that they weren't as good at low revs as other carbs. I think he was comparing my XJ650 with his 1982 Kawasaki 750. Unless I simply heard him wrong, to be honest I wasn't paying much attention, I just wanted to get my bike and leave - it had been in the shop for nearly two weeks!

The bike ran much better pulling off at lights and cruising at higher speeds/rpm once it was warm, but I was also riding it a little harder as I was getting used to it. I have a feeling the problems are more with the rider than the bike haha - I've only been riding for a bit over a year and had 6 months off, just jumped back on one.

 

38 MPG seems very low to me. But I only have my bike to compare to, so I could be off in my expectations.

Honestly, it sounds like a nice enough guy who didn't do a thorough enough job on the carbs. I'd personally take them off and double check his work, but I'll leave it to the more expert folks to give advice.

 

I would honestly prefer to sell the bike/take it to the wreckers, than open up the carbs. I'm ok when it comes to electronics, I can fix that - but when it comes to things that need grease/oil, I pay people to fix it for me. Especially if it's something that's going to carry me 110km/h and possibly get me killed haha.

The one time I tried to fix the bike myself, I tried syncing it and somehow screwed the revs over and couldn't get them below 4000rpm and had to take it to the mechanic like that. And apparently syncing the carbs is supposed to be an easy job...

Perhaps if I phrase it differently, the symptom will be clearer.
When the bike got well and truly warm near the end of the ride (I was back in city again, stopping and starting) the revs wouldn't stay constant when stopped at lights. There was a very slight rising and falling to it. If I tried to set it at 2000rpm, it might climb a bit, then fall a bit. But once I moved off the mark and started riding, it seemed to level out, feeling slightly underpowered in low revs with a slight 'missing' sound.
The sort of sound you can hear in an idling harley, where the revs aren't perfectly in order or a perfect hum, it has a kind of spluttering sound. As if the explosions weren't all perfectly symmetrical to each other. That describes the sound a lot better. I've heard a miss in my car before, but it's not that. It's more a quiet spluttering baredly audible, I haven't heard a bike without it before, it's just more apparent when you're riding at low revs.

 

Fitz...thanks, didn't know that--good to know!

Idle--these bikes don't idle dead smooth....there is minor hunting, etc.... but as soon as the throttle is cracked-----smooth is an understatement, and power is all GO.

Carbs--if he tried to clean a carb without taking one of the jets out, I can pretty well bet that THERE is a big source of the issues. Still never heard of the whole "hitachi's are good at the low end and that's why they stopped making them" thing before. My suggestion would be to get a replacement carb for the one that has the screwed up, unremoveable jet. Then, redo the whole rack yet again.

Boots-- if you're able to see right through the boots, you have a MAJOR air leak and that will make you run extremely lean, and lead to an overheating condition. If not corrected you can run lean enough to literally burn up the engine. Make sure that ALL the cracks are filled, sealed, etc......totally.
MPG - you should be getting closer to 50mpg

$$ - based on the description you gave, around here, that would be a $300.00 bike at best. Probably less, in most cases. But, you got it, you're having fun with it and learning with it and that's what counts.

I'd hate to hear what he charged you for the repairs,, on top of what you've already done to the bike, on top of what you paid for it in the first place.

Again, keep at it, keep asking us questions as you get stumped. Some answers you may not want to hear, but we're not gonna BS you, either. We'll give it to you straight.

Dave F

 

Yeah, 50 mpg is about what I get, maybe a little better (52ish, IIRC).

The experts here can get in and out quick and cheap (Fitz quotes $600 to $800 USD to recommission one of these bikes). Someone like me spends closer to the high end of that, plus a few bucks here and there for mistakes, along with more time. Add a shop into the mix and the sky is the limit on both money and time (and it's not necessarily done any better, often it's less carefully done than if you did it because their life doesn't depend on it being done right while yours does).

If you really don't want to get into doing the work yourself, you're probably gonna find that the bike costs you more than just buying something newer. Keep in mind that newer bikes have longer service intervals, so the costs for older bikes rack up over time as well. These bikes are reasonably cheap if you do the work yourself, but it's false economy to buy a cheap old bike and have a shop do the work.

 

$600~$800USD is cheap? And who said ANYTHING about "quick???"

I guess the cost isn't that exhorbitant considered to the cost of a new bike. But that price tag assumes you doing all the work yourself; that's just the basic parts cost.

Then there's the "work" component: what needs to be done is very TIME CONSUMING. It's far from "quick." Thirty year old bikes require a lot of LABOR HOURS for the things necessary to get them reliable enough to use as daily transportation. If you're paying somebody by the hour, you're quickly going to spend more than what a new bike costs to get this one proper.

We haven't even begun to discuss the front brakes yet; those will likely start acting up on you shortly.

 

Well, compared to a shop, or the time it takes me, generally the times I see people say things take are pretty quick.

A few hours for some of you guys compared to an afternoon for me, or a few days for a shop.

Everything is relative. $800 is very cheap compared to even an inexpensive new bike. An afternoon is very quick compared to waiting 2 weeks for a shop to get to it.

 

Yeah. Time vs. time

Let's see, I'm working on a 78 Goldwing at the moment.....stator replacement. Why did I get the bike in the first place? Cuz the MOTORCYCLE SHOP didn't even want to do the job because it takes SO much work and time. THEY sold the bike to me.

SO.........How much would it have cost the shop to do it? Probably around $1000.00 since the job requires TOTAL disassembly of the bike just to pull the engine out. THEN dis-assemble half of the engine, replace the stator, and all the gaskets on the back side of the engine. Do the belts while you're out, or end up with it back in the shop again, THEN re-install the engine, and the reassemble the whole bike.

How much has it cost me? (so far) .....about $175.00.

How quickly did it get done? (its not) Started in Nov., engine is back in the frame now. Gotta clean the tank out before going any farther........

Dave F

 

Sounds like the bike is trouble with an engine attached. I guess I'll just ride it into the ground before it costs me too much money.

If I got a roadworthy, I'd still get at least $1500 for it as a work rider, so I might just do that. Repairs cost me $510 in at the shop, which improved the bike a lot, but if it's jut going to keep generating problems, I'll just get a different bike. I really just want a bike that I can jump onto on a Saturday after sitting for a week and ride 400ish kms with a bunch of mates.

I'd like to think I could learn on it, but literally none of my mates know how to work on motors and the last thing I want is to have a bike that doesn't work in the garage. I've got friends with half-taken-apart bikes that sat in garages for years now, I don't want mine to become one of them lol.

I can't afford to work on it at the moment, I've got a big ride on Monday (public holiday ) and another big one next Saturday. If it dies, I'm just going to take a sledge hammer to it to make me feel better, take it to the dump and buy a different, newer bike.

I was thinking a Yamaha Virago - do they have less problems?

 

ANY bike that has been left to sit for many years WILL have issues. I don't care if it 'started right up" or not. There are things that MUST be done in order to make it reliable and safe again.

ANY bike that is brand new will STILL have things that will need to be done on a regular basis to keep it reliable and safe.

At this point, you KNOW some of the things that need to be re-done. We've already told you some of them.

If you have a couple big rides coming up, borrow a bike from a friend, and enjoy the ride. That way you don't have to worry about the bike.

Now READ---You've already sunk a bunch of money into the bike. Why sledge it? If you're going to get rid of it, there are plenty of XJ owners down there that would want it. I'd recommend that you slow back down, be realistic about the bike and take your time to do things methodically and correctly. That's what we're here for.....to help you do just that. Don't expect it to be done immediately and be stone reliable. Other guys who have their bikes torn apart for years, either have no clue what they are doing, and/or have no support group like us to help out.

Let me give you an example of my first 650.....I got it in non-running condition, hadn't been ridden in two years. I had it another two before getting started on it. I had to: put two new tires, new battery, replace the brakes, rebuild mastercylinder, rebuild caliper, rebuild carbs, new plugs, rebuild petcock. That got it to where it was ready at a moment's notice to ride. Never failed me. 12 years later, and many nos or near new parts as a resto project, I received a 2nd place trophy for it. Never failed me. I sold it last summer, with close to 40,000 mi on it. NEVER failed me. It was this forum that helped me do things in the right way.

Good luck with whatever you decide...........

Dave F

 

No offense, but the trouble is your approach to the bike, not the bike. The bike isn't trouble, it just needs attention.

ALL bikes need attention.

You got four paths here:

1. Buy a new bike (or reasonably newer bike) and get it serviced appropriately.
2. Learn to service your bike.
3. Keep buying older used bikes without servicing them and continually have problems.
4. Quit riding bikes.

Your choice, but I can guarantee you one thing: If you choose option 2, and you put your all into it, you can end up with something pretty special.

 

Sounds like you better get out while you still can!

On the flipside, once it is running properly it won't have "problems". Then you will just have to maintain it, like any other bike!

It would be foolish to run it in to the ground and take out your aggression with a hammer. Even with a blown motor, you'll still have some meat on the bone to part it out.

Don't take it out on the bike. The previous owners are at fault, not the bike...

 

Well, a bike is worth more in parts than together, like most vehicles. You might be able to get most of what you put into it parting it out on ebay to people who would love to have the parts.

 

Took it for another ride today and it's lost all it's low end power. All that happened was sitting for two days and it's no longer lifting up. It honestly sounds like it's permanently flooded, so I'm pretty sure you're right about the float bowls.
It's running ok, but I'm not gonna be able to take it next weekend. I'm going to buy another bike, 1995 at the oldest, and take that on the ride instead.
My bike, I'm going to get a roadworthy on it and sell it as a work rider. It's fine for 1/2 hour rides here and there, got me to work and back for months even before I had it worked on.
Unless somebody in brisbane wants to buy it as-is for $1000 bucks. Not sure what bike prices are like over there, but the cheapest bike you can get with a roadworthy that isn't a scooter is $1500 over here, so that's the minimum it's worth.
And no, I would never take a sledge to it lol. I just want a bike that I can ride whenever I want without maintaining myself. When I need it serviced, I'm more than happy to pay people to service it for me so I don't have to do it myself haha. Computers and electronics, I do myself - mechanical stuff, I don't.

 

That's a new bike.

Looks like you're choosing option 3, though. A 1995 is almost 20 years old, it'll have some quirks which lots of mechanics won't know about. One last appeal to good sense: save up until you can buy something new, you're gonna spend that much (or probably more) anyways going the route you picked.

Good luck.

P.S. Buying a cheap used bike just before a long ride is just asking to be broken down on a long ride.

 

almost sounds like valves are not closing all the way. At low rpms the valves lose too much fuel through cylinder flow. Once you get to higher revs, the speed of then engine overcomes the flow and you get power again.

I'd suggest that you ask the repair guy for a copy of the numbers from when he did the shims. I'd also suggest the following, though you may not want to hear it: There are some people that have the idea that a shim check is simply checking to see if there is still clearance between the shim and the cam. That is NOT to correct way to do it. Get particulars on just HOW the check was done.

If you wish to ge the bike 'roadworthy' you're gonna have to do all the stuff that you would do anyway. Plus, make sure you write down WHAT you do, keep receipts of what you do and get, so the next owner can have that info, just like you should have had so we can answer questions rather than keep asking more.

Dave F

Dave F