200s compression really high.

[MonkOFox]

Okay so I tried to crank it today and the compression was so high it's ridiculous. I would pull sometimes and the trike would come off the ground.... I don't know what the deal is.
I don't even know where to start to even try to troubleshoot this.

[MonkOFox]

the piston goes up and down but only 1/2 a cycle per pull. Could a cam chain being too tight do this? I pull the decompression lever back and it's still about just as tough.

[kb0nly]

You put new rings in it??

[MonkOFox]

Yeah a while back, when I put in the piston. I had everything on except the valve cover and it ran before. Only thing different is I bought a new valve cover on ebay. In the manual it says decompression lever could cause it, but I never used the thing before...

[MonkOFox]

I had tore it down to do a top end. Replaced the piston/rings while I had it apart because my buddy had one. He had ordered one for his 200x but it was stock instead of bigger like he needed, so he gave it to me. I slapped it back together and it ran but it started leaking oil between the head and jug so I tore it back down and had it back together (minus the valve cover). Not sure what could have happened...

[MonkOFox]

It was a little tougher to pull after the new piston but I figured the compression was a little better with the new rings and stuff. But now is just... wow. I stopped because I don't want to mess up the grabbers on my pull start.

[Yamaha_Rules69]

Something is most likely binding under the valve cover by the sounds on it. Take off those 2 17mm nut caps, one on intake and exhaust. Look in there to assure the cam is in correct, the chain is on the cam sprocket, and the tappets are not adjusted incorrectly for starters. Let us know what you find!

[MonkOFox]

What are tappets? I'll brb.

[MonkOFox]

Okay so I took off those caps on the valve cover. I can't really see past the rocker arm. I can see a lobe I think and when I pull the starter, the arms go up and down. Here are some pics:

178676178677

It doesn't sound like those arms are 'tapping' the valves though. When I pull the starter, the bottom sounds like a 'Gulp' and then air goes psssssssssss. I wonder if the valves aren't opening?

** that's the exhaust side too.

[MonkOFox]

Where do I get a 'Feeler Gauge' for adjusting the valve clearances? The valve cover is off of an 84 200s, mine is a 85. So maybe it has to be adjusted differently, not sure.
Nvm, they have them at Harbor Freight. Kind of looks like a allen wrench set but with flat pieces of metal instead. Are they pretty flimsy? because it's going to have to bend weird to
fit between the valve and the tappet right?

[MonkOFox]

I don't know. I took the pull start off and put it back on the 'T'. But the tappets are fairly close to the valves. I can't verify the 0.05mm but yeah. Even when I turn the flywheel manually with a screw driver in the flywheel, it's not very easy. I mean I can do it but the piston makes a squealing sound or rubbing. Like rubbing a balloon (slightly). Like there's no oil or something. I don't know. I'm probably going to have to tear it back down I guess...

[CodyRosa]

My wheeler does that with a high comp piston.. my decomp lever wouldn't stay up. I'd pull till it got to that hard spot, slowly pull until the piston went down and then pulled it hard and it started up.

If you're hearing squealing i'd take it apart as well. Before I put my high comp piston in I put just rings in and I could hardly pull the thing AT ALL. Then my recoil wouldn't go back in. I took it apart.. again and it ended up being the camshaft locked up somehow. (mind you I never ran the thing.. I just tried pulling it for the first time) I took the CDI cover off and the plate and all that to see the camshaft. It looked fine yet wasn't moving and I couldn't even pull it out like I normally can.

Basically what I'm saying is it's very easy to mess up, and my mess up (although i have no clue what happened) was minor.

Hopefully nothing got in between the piston and cylinder. Please let us know more once its tore down!

[MonkOFox]

Yep ill take pictures and stuff. Gotta pull it out of the frame and stuff... Lame.

[MonkOFox]

I do remeber when putting the cam in it didnt just slide in easy. Had to kind of navigate around the rocker arms. It was tdc though.

[MonkOFox]

I had the exposed cylinder head covered with a plastic bag. But not the carburetor boot or exhaust hole (it sat up for about 2 years probably). Maybe I have an obstruction... I'm sitting at work tweaking like a crackhead thinking about it haha.

[MonkOFox]

Ok, so I took the motor out and took the spark plug out and the cdi stuff. I pull on the starter and it was smooth as can be. So I was like, hmmm. So I put the spark plug back in and viola, hard to start again and really really hard almost knocked the motor off the table not expecting it. So I tore it down anyways and there are no obstructions, everything looks good...

Here are the pictures I took:

178702178703178704178705178706178707178708

Could the dirtiness on the valves/piston cause it? The timing looked good. I did the T/O thing and then the F and lines on the pulse generator and the part that slides on the cam, stator, that's it. Now, I did mark the letter and not the line with a circle above it, could 1 tooth off or so make it harder, that much?

Also, I inspected the tappets and they were compressing the valves like the should, even when the spark plug was in and harder to pull. I'm confused... With the valves opening and closing that compression shouldn't be that high. Don't even think I could kick start that thing...

Thanks.

[MonkOFox]

I cleaned the valve... combustion chamber and the piston:

178709178710

[MonkOFox]

I'm starting to think it has to be the valve clearance. I'm going to adjust them closer. Maybe the valves aren't opening enough. It's pushing the pin and the spring is compressing though. That's the only different part I have as well.

[Dirtcrasher]

What is the PSI??

Was the rubber plug behind the cam journal installed?? If not the cam doesn't get enough oil.

You are running rich, def carboned up...........

[MonkOFox]

Yeah I never cleaned it before. And didn't adjust the fuel mixture screw list supposed to. I'm going to adjust the valve clearance and hopefully the compression is so high. Then I'll test it. If I can't turn it over, lean or rich is the least of my worries. I'll post pictures of how I reassembled.

[MonkOFox]

Here are the steps I took:

Put the bushing in:

178714

Put the plug in:

178715

Oiled everything: the pocket and springs.

put the cam in lobes down with sprocket on and chain:

178716

Then aligned the T and O marks like said in manual:

178717178718

put the gasket stuff on the cover:

178719

Put the cover on and finger tightened until the stuff just started to ooze out and am currently letting it set up for 1.5 hours:

178720178721178722

[MonkOFox]

I think I found the problem as well:

178723178724

The clearance is like 2.5 - 3mm. Don't know if the person that parted this out did this or what or if the previous owner had longer valves or something?? Anyways it's definitely not .05mm like it's supposed to be.
So I'm thinking that's the reason it was so hard to turn over when the spark plug was in, the valves weren't opening enough.... I'll adjust them and put the plug in at about 9:15 and see it's any better.

[MonkOFox]

How long should I wait for the silicone to set up before I actually try to start the machine? Full 24 hours?

[Dirtcrasher]

Yes.... 3 bond or similar, just use a tad less and stay back off the journals per spec in the shop manual. Aftermarket cams need .002-.003 additional gap @ the rocker setting if it is not stock.

[Yamaha_Rules69]

I usually start it a couple hours after applying the sealant, but I use Hondabond, and it sets up fast. Be sure to get a feeler gauge, YOU NEED IT, you can pick one up at any auto parts store. They are made of thin metal, there are like 30 of them on one stick, all different thicknesses, select the right size, I believe its .003 inches both intake and exhaust, but check manual to be sure. Its a VERY small gap there, you'll never get it by eye. Its a little tricky the first couple times, but it will become easier after you do it a few times. You want there to be a slight drag on the feeler gauge, not too tight or loose. You have to adjust the gap by turning the square nut in or out, and the nut is to lock it tight. Turn the square part above the nut in with the feeler gauge in between, until there is slight drag when moving in and out. Hold the square nut in place, and carefully tighten the lock nut. Double check your work to make sure its right. If you don't have the special square wrench to hold the square part, use a needle nose pliers to hold it. This is the way I do it, as I do not have that tool, but this method works alright.

[MonkOFox]

The cam, valve/spring and rockers are all stock. I don't know why the tappets were so far out though. I don't have any feeler gauges, just going to do it by touch.

haha, nvm, feeler gauge it is.

[MonkOFox]

Yeah I have a smaller 10mm wrench and it will box on there enough to loosen/tighten. Are those feeler gauges super flimsy? So it can go over, vertically down and then between the tappet and valve? Or do I specifically need to find bent gauges?

[MonkOFox]

It's .05 mm for this particular motor. At least that's what the book says.

[MRSOUND]

Feeler gauges will be "flimsy' on the smaller thicknesses. Think of this way, an average piece of paper is .004 -.005 thick. .05 mm is approx .002

[Yamaha_Rules69]

Yes, the gauges are flimsy, and able to bend just right. I was talking about inches, its 3 thousandths or .003in, I wasn't talking mm's. I live in the USA and use inches to measure, dosent the manual give an inches measurement, it usually gives both side by side? You could use a piece or regular notebook paper as a feeler gauge, it is .003in. Otherwise, just do it the right way and get the feeler gauge. Good luck, and let us know what happens!

[MonkOFox]

Oh yeah, .05 mm or .002 inches. I'm in the US too lol. I just called a buddy to see if he has a set.

Oh, and I will keep you guys posted! Hopefully a video of me driving around tomorrow!

[MonkOFox]

Ok im a dingaling i didnt have valve cover torqued down. When i tightened it down, there was much smaller gap. If i pull in the tappet though i can still here it tapping. Im going to check them anyway tomorrow once i get my feeler gauges. Would .001 of an inch make that much difference in difficulty of pulling the starter? On the up stroke, i can hear hissing. I guess that is the air going out the exhaust valve?

[MonkOFox]

If i try to pull up hard, it seems like its just locking...

[Yamaha_Rules69]

Man it seems like you have something seriously wrong, unless your valve clearance is WAY too loose. Are you sure the timing chain is not damaged or binding? Check the clearance first, then go from there.

[rg97]

I cleaned the valve... combustion chamber and the piston:

178709178710
Well, your piston isnt helping your problem any... The number on it corresponds to a 12:1 compression. stock is like 8.5 or 9:1. My X has a kick start and its tough to kick at 10.5:1... with a pull start, 12:1 will be HECK to start

[MonkOFox]

Crap.. Is the compression determined by the rings?

[MonkOFox]

going to my buddies to get the old one.

[rg97]

Crap.. Is the compression determined by the rings?

No. Look at the pic in the link below then read my explanation
http://farm9.staticflickr.com/8241/8626261522_218de9095f.jpg

(http://farm9.staticflickr.com/8241/8626261522_218de9095f.jpg) The piston on the right (a high comp piston similar to yours) has a more "domed" top, and a larger piston top than a stock piston (on the left in the picture), as you can see, so it takes up more space in the combustion chamber and makes the fuel/air mix compress more, making a more powerful explosion. Yours is like the one on the right as well, and a 12:1 piston is the highest they make for the ATC's, and the 12:1 is meant for racing gas only, something like leaded 98 octane or above. thats why its heck to pull over, and if you want, a stock or 10.5:1 piston would be much better!

[Dirtcrasher]

I hate 12:1 !!!!!!

[Thunder God]

A high compression piston will make it harder to pull start, but if I were a bettin man I'd say you replacing the rocker cover is the problem. To test my theory I would suggest you slip the timing chain off the cam gear and try turning it back and forth with your fingers. It will NOT be able to go all the way around but it should move easily (in/out and back/fourth) I suspect the two halves do not match up PERFECTLY. As Honda recommends you replace both head and rocker box as a MACTHED SET.

[MonkOFox]

Damn, that's some sad news about the valve cover having to be the same... Lame. Well here is the old piston:

178728178729

Another thing, this is strange to me. When you're timing, you put the T and then line up the sprocket with the 'O'. I was manually turning the crank and noticed this:

178730178731

How does it end up 180 degrees off?

[MonkOFox]

Does it do two up and downs with one combustion or something? Another thing, the motor turns counter clockwise right?
I googled 4 stroke engine and:

"...The piston make two complete passes in the cylinder to complete one operating cycle ...". So that probably explains the O and T being
180 degrees off in my previous post.

[MonkOFox]

Ok so, I have the motor parts back together with the old stock piston. Just have to get it in the frame and set up the stator/generator. Then I'll give it a pull and see if it's less difficult to turn over now. I pulled on the cam and it slid out (I had to turn it counter-clockwise slightly for it to come out). It may have been a little difficult because I adjusted the clearance closer just to see if that would make a difference (with the old piston in).

Tore down the carb to clean it too. It had a thin layer of varnish in the bowl so I'm sure some of the jets are clogged. Been a sittin'. How do you drain a carb for sitting up a long period of time? Or is there no real way to prevent 'gunking'?

I'll keep you guys updated! : ).

[MonkOFox]

Okay, got it back together with the old piston and pulling it was a breeze. Set the valves best I could (I think it was right). It's at a really weird angle, so I put the feeler underneath, let it hang and just snugged the tappet down until it wouldn't move then backed off until it would drag in between. Problem though, it's leaking like crazy. drip after drip and it's hissing between the cylinder head and jug. Not between the bottom end and jug though. I tried to snug the 8mm cap nuts on the cover more, but didn't really help. Guess I need to test the compression to make sure maybe there isn't too much?

A little oil probably got on the gaskets when I re-tore it down. Is that a no no, or does it matter that much? I'm pretty comfortable putting it back together and stuff. Could timing being off make it leak like that? I put the 'T' on the flywheel and the 'O' on the sprocket lined up at the same time. Put everything on, then advanced the timing to the 'F' mark and put the stator/pulse generator on and then the CDI cover.

It's idling high, but I can tinker with that. I'm just sad that it's leaking soo much oil : (. I'm using 93 octane gas, does that matter? Should I only use 87? Here is a video of it running:

You can see a drip on the right side of the bike and later on you can see bubbling around that gasket. I can upload a better video if you want. Sounds like it's running good, just leaking like crazy for some reason.

www.sportsmanstuff.com/1013131432.3gp

[rg97]

Whenever I put my X together, the head leaked bad until I put the proper torque on all the head bolts. You will need a torque wrench, probably 1/2", and then torque the scorn nuts to 22 ft lbs and the socket head cap screws to 9 ft lbs. Just 'snugging' them wont do the job. They all need to be correct torqued and all even or else somethings going to go way wrong. Do it right the first time

[CodyRosa]

Dont use a 1/2 haha. Its a 12mm for the acorn nuts on top. I laugh because I almost stripped one completely when torquing past 10 ft lbs using a 1/2.

[Dirtcrasher]

Okay, got it back together with the old piston and pulling it was a breeze. Set the valves best I could (I think it was right). It's at a really weird angle, so I put the feeler underneath, let it hang and just snugged the tappet down until it wouldn't move then backed off until it would drag in between. Problem though, it's leaking like crazy. drip after drip and it's hissing between the cylinder head and jug. Not between the bottom end and jug though. I tried to snug the 8mm cap nuts on the cover more, but didn't really help. Guess I need to test the compression to make sure maybe there isn't too much?

A little oil probably got on the gaskets when I re-tore it down. Is that a no no, or does it matter that much? I'm pretty comfortable putting it back together and stuff. Could timing being off make it leak like that? I put the 'T' on the flywheel and the 'O' on the sprocket lined up at the same time. Put everything on, then advanced the timing to the 'F' mark and put the stator/pulse generator on and then the CDI cover.

It's idling high, but I can tinker with that. I'm just sad that it's leaking soo much oil : (. I'm using 93 octane gas, does that matter? Should I only use 87? Here is a video of it running:

You can see a drip on the right side of the bike and later on you can see bubbling around that gasket. I can upload a better video if you want. Sounds like it's running good, just leaking like crazy for some reason.

www.sportsmanstuff.com/1013131432.3gp

I actually grease ALL my gaskets that do not have pressure or vacuum. I also chase all my threads and grease all the bolts.

Valve adjustment can be a PITA. When you tighten the lock nut, the square headed stud moves unless you can hold it and that is not always easy. I tend to set a valve a bit loose and when I tighten the nut, the setting changes because the adjuster moves and I just play with it back and forth until I get it right. It's hard to get tools in all those cramped areas.

This is why I LOVE the 86/87 200X valve adjustment, it is so quick and easy!! I think the future 350X would have had something similar..........

[MonkOFox]

Thats the thing, they were torqued about 2 lbs over spec and it was still leaking. So i 'snugged ' it more, just the cap nuts, not the torque screws. Its leaking a little less.

[MonkOFox]

I dont want to tighten them too much, dont want to crack the cover or something. Wonder if its binding on a dowel pin or something. It looks seated though.

[MonkOFox]

What do you mean by no pressure or vacuum, it seems like there is pressure pushing the oil out. Between the head and jug. Would higher octane gas cause too high of an explosion and cause too high of pressure on the chsmber?

[rg97]

Dont use a 1/2 haha. Its a 12mm for the acorn nuts on top. I laugh because I almost stripped one completely when torquing past 10 ft lbs using a 1/2.
Whether you use 1/2 or 3/8, 20 ft lbs is 20 ft lbs. 1/2 just makes it much easier, because the 1/2 ones are longer thus more leverage as you works towards 22 ft lbs'

[MonkOFox]

Well, regardless I'm going to have to tear it down to replace that oily gasket now. There is a machinist friend of the family up the road, going to get him to resurface the head. Do I need to resurface the jug too? Also, will I need to get a thicker gasket set or something? Going to spray some copper stuff on the gasket before I install next time as well. Yeah, all I have is a 1/2'' torque wrench. I have reducers though for the 12mm cap nuts and torque bits.

What brand of gaskets are good? Athena? Vesrah?

[6speedthumper]

I prefer Cometic. Can't speek for Athena, but, I'd trust Vesrah. And I believe what DC meant about "greasing the gaskets", is rubbing some clean oil on the gaskets, then installing them. I do the same. Actually helps to create a better seal, and if you are in a pinch and need to reuse a gasket (like a clutch cover gasket) it shouldn't stick to the aluminum and tear apart when you remove the cover. Like DC said, don't do that on gaskets that are under pressure, or under vacuum. Those types of gaskets (like a head gasket) will leak.

[kb0nly]

Did you remember the o-ring on the one stud at the headgasket?? Thats a good source for a leak if you forgot that.

[MonkOFox]

Yep, I have that in there. If you're looking down at the motor (from the flywheel side), it's on the back left corner, it's leaking at the front left. I think it's just warped. So gonna take it down, get the head and jug resurfaced and then spray that copper crud on the new gasket and see what happens then. It's all hissing and bubbling on that corner (where it was leaking before). So I'll just tear it down and do it right and have a 100% machine.

Thanks for all the help! I'll post here again when I get all that junk done.

[CodyRosa]

You know 1/2 is a tad bigger than 12mm. 1/2 will strip those out after awhile. I used 1/2 fine until trying to torque it higher and it finally gave lose. My manual only says to torque at 14 ft lbs so if mine stripped out after a few times I can only imagine how quick 20ft lbs will strip it. I'm just trying to save the guy time by giving him the right size socket. Thats all

[MonkOFox]

If the head is leaking, should I get both the head AND the jug resurfaced??
Also, will I need to use two head gaskets?

Thanks!

[rg97]

You know 1/2 is a tad bigger than 12mm. 1/2 will strip those out after awhile. I used 1/2 fine until trying to torque it higher and it finally gave lose. My manual only says to torque at 14 ft lbs so if mine stripped out after a few times I can only imagine how quick 20ft lbs will strip it. I'm just trying to save the guy time by giving him the right size socket. Thats all

Sorry man I think you completely misunderstood. When I said 1/2" originally, I meant the torque wrench size, aka the size of the square drive, not the size of the socket which is 12mm. A 1/2" wrench is larger and gives you more leverage, the socket size will always be 12 mm

[rg97]

Yep, I have that in there. If you're looking down at the motor (from the flywheel side), it's on the back left corner, it's leaking at the front left. I think it's just warped. So gonna take it down, get the head and jug resurfaced and then spray that copper crud on the new gasket and see what happens then. It's all hissing and bubbling on that corner (where it was leaking before). So I'll just tear it down and do it right and have a 100% machine.

Thanks for all the help! I'll post here again when I get all that junk done.

If you got a new honda head gasket, you DO NOT put in the oring. Because of an asbestos scare, honda redesigned the head gasket and eliminated on of the dowels and the oring that went around one of them. I'm not sure if this applies to other brand gaskets, i just ran into the problem because i use OEM only. there was actually a sheet of paper that explained the problem and the solution inside the kit.

[MonkOFox]

Hmm, it wasn't an OEM kit. Some package off of ebay. Can you reuse the bottom end gasket and only get a new head gasket?

[rg97]

chances are when you rip it back apart, the gasket will be toast. even if it isnt though, spend the few bucks and get another one

[MonkOFox]

Yeah It's really flimsy anyway. Would you recommend me get the head and the jug (the surfaces that meet) machined/resurfaced? If so, how would I know whether or not to use 2 head gaskets or not?

[rg97]

put a straight edge (that you know is 100% straight) across the head and jug at several points and angles to see if they are warped before you decide on resurfacing it. Just because you're leaking oil doesnt necessarily meant that it's the mating surface's fault. make sure to "scrape" the mating surfaces (top and bottom) to remove all the old gasket crap. Dont gouge it, but all of the old gasket needs removed so you're down to bare metal. Major imperfections could be a problem in the surfaces, small stuff probably wont cause you any problems. replace the o-ring that goes between the head and jug, see if that works. buy a honda OEM gasket, not any of the other stuff. If you buy OEM, then it should come with an instruction sheet about the changes to the gasket. If it doesnt, I can make a copy and post it. once you do that stuff, try a dry fit together of the engine, see if you can get a feeler gauge, like .002", into the side where its leaking.

[MonkOFox]

Awesome, I can handle that. My brother in law has some gasket remover stuff I'll try that and some carb. cleaner / alcohol to get it clean, clean. I'll slap it all together, oil free, and see how everything fits. Torqued down I'm assuming my smallest feeler shouldn't even fit, so I'll do that sometime in the next couple of weeks and post some results!

[CodyRosa]

Oh my bad RG! haha I was thinking thats what you meant but just kinda assumed 1/2 socket. Now what you say makes perfect sense =D lol

[MonkOFox]

Can running too hot of a plug (over time) eventually cause a head gasket to leak? I'm sure the integrity of the gasket degrades over time which can be an issue. Also if the head is warped. Warping is caused by over heating right (or can be)? I'm just trying to get a better understand of why and how they can potentially start to leak.

Haven't tore it down completely yet. Took the CDI off and stuff. Having my 3rd boy tomorrow morning so I'm a little preoccupied!

[oscarmayer]

i think you have the cam binding. when you changed trhe valve cover, you know that part of that cover is "matched" to the head right? so changing them out means the clearances are different, this can cause binding. the only way to fix is to take the head completely apart take the cover and head to a machine shop and have them home the cam journals. that will make then true into spec. you can test this by going to the auto store and getting micing putty (forget what they call it now), and use that to tell the clearances of the cam to the journals when you tighten it down. i am pretty sure you will fid it out of spec.

[MonkOFox]

I changed that piston. The 'compression' issue seems to be resolved. Though, i dont doubt that head and cover arent matching completely. I got it running though. Could that binding make the head and jug not meet flush?