Did a compression test finally......

So i finally did a compression test on my bike to see if i could have a bad valve seal or piston ring letting oil run by. My bike bikes out a good amount of smoke when it warms up. Also did a small check to see if there was gas in the crankcase (Stick + fire). oil on the stick didn't light up fast so theres no gas there........i'm basically out of idea's at this point. Need a pro for this one, haha. :?



PS: Compression test numbers are
140
150
145
140

 

Compression numbers look good. Could be oil ring, but not likely.

You need to SMELL the oil, not light it. The nose is very sensitive for gasoline.

Bad valve stem seals normally smoke more at start up because the oil has a chance to run down and collect while parked.

 

Paint thinner is the only way i could describe the oil, Didn't really smell any gas though. I have run the bike longer and it auctually smokes more at warm then it does at start up. When i rev the engine it pushes out more smoke as well. It does need a sync and i did take the carbs out and made sure they where clean when i bought the bike. Also i did unskrew one of the sync skrews about 3-4 whole turns on the bike when i bought it. Could of i touched one of the mix skrews when i took the carbs off?

 

Also. I did put 1 can of seafoam through the gas tank when i bought it trying to clean the carbs. Could this be still in the engine some how and pumping out the smoke?

 

First off, a compression test won't reveal a bad valve stem seal.

What color is the smoke? (seriously.)

Are any of your plugs oily or black/sooty?

Are ALL of your plugs black and/or sooty?

If you KNOW (and it sounds to me like I would agree) that you need to sync the carbs, then check/adjust your valve clearances and get the carbs sync'ed. Then see where you're at smoke-wise.

It would REALLY help if we knew more about your bike; like what it is and whether or not it's stock or has carb/airbox and/or exhaust mods, etc. Put it in your signature.

 

The smoke color is a gray/white.

All of the plugs are black and have some oil on them.

I'm waiting on my sync gauge at the moment and have a yics eliminator for the sync. Hopefully the sync will be done next week.

Where can i find a measurement tool for the vavle clearances/ what should i use?

Going to grab some new plugs today and hopefully a vavle cleareance tool and do all of that this weekend.

 

PS: Have been running the bike on only choke becuase of the need to sync the carbs. I think this is part of the reason the plugs are black.

 

So today i started the bike up and let it warm up. Was ready to take it for a ride and try to see if the smoke may be moisture or something along those lines. The bike warmed up and i reved it some and let the throttle go and it just sat at 3k rpms. I had to hit the kill switch and i reajusted the idle knob low to see if that would help. Tried it again and it sat a 1k. Reved it and it came back down to 1k as it should then i noticed something bad. Smoke out the rear end was pumping out in heaps and some of the smoke was coming out of the connectors of the exhaust.

 

I only get whitish out of the exhaust, when i have seafoam in the tank. How many tanks of gas have you put through since you had seafaom in it?

When you put the seafoam in, how much seafoam did you put in to gas? ex.) half bottle to one full tank?

 

Put at least 1 can through the tank itself and at least 1 tank through the tank trying to fix it.

 

How does the bike itself run? My latest smoked really bad while sitting. Carbs were completely out of whack. Fixed that and not a puff of smoke at all now. If you're running rich, that can cause it.

 

you need to run a bit more threw it one bottle of seafoam treat like 10-12 gallons of fuel. While it is good stuff too much is not a good thing. did the smoke start when you put the seafoam in or has the bike always done this since you owned it? You should check your valves before trying to since your carbs if they are out it will be a real pain to get the motor sync'd properly.

 

The bike itsself seems to run ok Coach and i should be able to do a sync next week i hope. And i plan on probably do valve clearances tomorrow on it. Just not sure where to pick up a tool for the clearances.

 

Valve feeler gauges can be had at any autoparts store or even some discount stores. Usually, you can at least find them with both metric and customary units on them. (Saves conversion). I used standard straigth ones and had no problem, but some people use ones that are bent on the last inch or so to help get in tight places.

 

Sounds good KT

PS: Coach the bike isn't pumping out black or blue smoke. Its more of a white/gray.

 

If you put one can to one tank, and have only run that tank and one other one through it since... i'm betting after you run 2 or 3 more tanks through. You're smoke will magically go away.

One can of seafoam to one tank is WAY too much, a half can to one tank is still a very strong mixture. So even if you've run a tank after that seafoamed tank, the consentration will still be fairy strong. Enough to smoke i'd imagine.

 

You wrote: "PS: Have been running the bike on only choke". Hmm! If you only can run the bike with the choke on you got problems with the carburettor adjustment and of cause the spark plugs is black and you will get un burned fuel = smoke in the exhaust. KN intake filters probably require other jets. You can get an oil ring fault on one cylinder but not likely on all four cylinders at the same time. There are others with KN filters, try to search information on how they did the carburettor setup. Running on choke, by the way, increase wear on cylinders (oil is washed away on cylinder walls).

 

Thanks for the info Pirok. Now before i get into doing my valve clearances what should they be? Look at my haynes book here its telling me .16 mm for both inlet and exhaust.

 

Also will i need any kind of special tools for this?

 

The Haynes book has been confiirmed to be wrong. .11mm-.15mm intake; .16mm-.20mm exhaust, ALL 650s.

Feeler gauges (preferrably "metric" it makes it easier) to check the clearances; the bucket hold down tool (or an alternate method of holding the valve open) to remove the shims.

 

Ok everyone i'm back and now i'm doing my carb sync using a morgan carbtune. This is becoming hard and just a tad bit confusing. I'm getting readings from 1 and 2, but nothing from 3 and 4. Any ideas?

 

Sounds like air leaks. You should see reading on all 4 .

 

Well i think the syncing is skrewed up beyond belief. I start unskrewing #3 slowly and started to get readings from it. I did a wb40 on the boots when it was running. And it didn't rev up.

 

Rubber hose on #4 just poped off, that can't be good........

 

Didn't rejet for K&N air filter, didn't think i had to. Very possibly one of my problems right there.

 

You HAVE to re-jet. You're going to have to play with jet sizes until you get it right. Then re-sync. And play around with the adjustment some. Do a search on here for a thread about re-jetting after pods.

 

Was just looking at one, figure i may as well just go back to stock. Save me time and alot of hassle rejeting. Going to go to my local yamaha dealer tomorrow and see if he can help me out with a Stock filter.

 

I wish I had the air box, it would have made for a lot less headaches.

 

Haha, getting some success. Ok thus far i found my old stock air filter =D. Have been fiddling with #3 and tighening and tighening. Abouto i'd guess 4 full turns or more easly i start getting a reading on #3. 2 more turns on #3 and its getting up there with one and 2. Hopefully this was my smoking problem.

 

So i started the bike up after getting 3 just about up to speed with 1 and 2 and there isn't any smoke from what i can tell and the emissions smell more like gas now then anything i can tell that much. Just one question though, what should the emissions smell like?

 

OK I'm confused about what you are adjusting. # 3 is fixed - it gets "adjusted" only by the idle adjust screw Which moves all 4. To sync you read 3 and bring 4 to match. make sure 1 and 2 are equal (they are tied to each other) then bring 2 to match 3 and the pair (1 and 2) will move to meet 3 since they are slaved).

So what are you adjusting to make 3 give you a vacuum reading?

 

I was pointing towards the carbs themselves. 1 and 2 are very close as a pair. Was more concenered at the time with making sure i could get 3 (the third carb) up to par with one and to and to make sure it was getting a reading overall. I was adjusting 2. The closest to the throttle. Seems like the thing has become the one bike that needed a sync the most. Next is the 4th. Getting no vaccum on that one as well. Just seems to me like the thing has never been sync'd or something along those lines. Just needed the sync very badly.

 

When warmed up and choke off, it should smell like exhaust...
Seriously, you shouldn't smell gas after the bike warms up.

 

Exhaust does smell like exhaust, but i think the mix is wrong. Maybe too lean? Small poping sound from exhaust when i drop from about 4-5k rpms. Also the idle is "Hanging" Didn't have this problem before when i first bought the bike so it should be fixable with everything that i have. Any suggestions?

 

As bill mentioned above, #3 cyl/carb is your baseline. You have to synch the other cyls/carbs to #3 as it does not have a synch screw. Once the system is bench synch'd, the only time that #3 butterfly moves is to lower/raise the overall idle point. Thats done with the idle adjustment screw between 2 & 3 as you know. This only adjusts the idle, not any synch between cylinders/carbs.

The classic "hanging" is usually a small air leak and/or out of synch (yes, we're back there!).

You are correct, popping is usually a lean sign.

 

I took the carbs out of the bike before and then it didn't have an air leak. All of the merc tubes on the bike are on the same level. I do understand how they are sync'd now. The only thing that dosen't make sense is the hanging. Figured the hanging would be solved with the sync, apprently it wasn't.

 

Just a PS as well. At first when i started syncing i was getting no reading at all from #3 on the carbtune. I unskrewed the second sync skrew a good 6 turns and got readings on it finally. I then started matching 4 to 3 and then 1 and 2 to 3 and 4. All the mercs are showing the same lvl now. Won't have the time tomorrow to take a closer look at it. I think my next step though is a unlit propane torch. How can i get the mix right as well on the bike?

 

JC

Maybe I am misunderstanding, but just trying to shed light and help nonetheless. If, after a bench synch, you have to turn a synch screw 6 turns to get a reading then something is amiss. To turn a synch screw from a bench synch condition (which is the "nearly there" state) would almost certainly put it right out again.

Moreover, not getting a reading on 3#? Turning any of the 3 synch screws doesn't alter #3. No. 3 doesn't have a synch screw as such.

Having said all that, if your synch is now correct as you say, good job. The hanging could be a lean mixture (which could tally with your "popping").

We're not clutching at straws just yet!

 

I didn't bench sync the carbs. I'm using a carbtune pro for the syncing. And before i did the sync about 2 weeks back i was having trouble finding the idle knob (which i didn't know was a knob at that point in time) and turned the #2 sync skrew inwards one too many times. I just about put the #2 sync skrew all the way down, so by connecting the dots and just flat out making sense thats why i wasn't getting a reading on the #3 at first. I know its supposed to be the slave and have no way of syncing out, but some how the #2 plug sync'd it out i think. I was getting readings from carbs one and two at the begining of the sync and now all 4 carbs have readings and are on the same level . I'll take a pic soon here when i get the chance.

In the mean time wish me luck tomorrow. Going to start my weekend training course of MSF here in VT. If all goes well i'll have my endorsement by the end of it all.