225dx wont stay running

[85burbanator]

ive been tinkering on an off with my 83 or 84 225dx for alittle bit now and cant get it to stay running. here's a run down of whats been going on with this thing.

i got the bike from a buddy for hella cheap as it was in a field for a few years. said it ran when they parked it then it gradually found its way into the lawnmower graveyard he had goin on.

i started by cleaning the carb and replacing a few jets and o-rings with the proper replacement. put a new plug and battery in it and it turned over great but wouldnt start. it had great spark and what felt like good compression (dont have a tester). fast forward to about a month ago. we got it run after pouring some gas into the carb. it took some coaxing and at first would only run for a few seconds then die. it would then take a few minutes before it would run again. we finaly got it to run for about a minute or 2 by playing with the throttle. then it died and wouldnt restart. while it was running i noticed oil coming from the crankcase breather hose that came loose from the air box.

today i changed the oil and tried to start it via the elctric starter and it wouldnt start. i got it to start by pouring alittle gas in the carb and using the recoil start (same way we got it running before). it ran for about 1 minute then died and wouldnt restart. i decided to check the valve timing but the book (clymers) was very vague. im assuming the little groove in the threads on the flywheel sight screw hole deal is what the flywheel timing mark should line up with but again it didnt say in the manual. i looked at the timing gear and the mark on the gear was at about the 1o'clock position with the stationary mark at the 12o'clock position. both whould line up with the perspective marks correct?

im sure the carb needs some adjusting and posibly the timing needs to be reset but why wont it start with the electric start? it turns the motor over just fine and its getting spark with both the electronic and recoil starters. i want to get this dude up and running for the misses this winter so i can ride my bike and she can ride this. im kinda selfish i guess:twisted:

any ideas would be greatly apprecieated as i cant really afford to take the bike in and have a shop look at it.

thanks
mike

[trizilla]

start by checking fuel flow to the carb. pull the line off the carb and turn the petcock to the on position, if you have good flow turn it to the reserve position and check that also. if there's no or very little flow remove the petcock from the tank and thoroughly clean it. once you've done this go back through that carb and double check everything, be sure to set your pilot adjust screw at the proper setting. once these are done go back to the airbox and check your filter out, im betting that this will be no good if its been sitting for a while. if your fortunate enough to have this filter be good make sure its clean and re-oiled. i think will get you going.

[85burbanator]

i already cleaned the petcock and al lthat. it has full flow to the carb. i should have stated that already, sorry. im gunna take the carb apart again am check it over to see if anything is clogged again. it doesnt have an airfilter on it. there were any hoses on the airfilter box to the carb. there was a cap on the carb when i got the bike so im not sure if anything got into the motor but it didnt sound like it.

mike

[Lukeatc185]

i think i read on here a while ago that if you have bad rings you can get blowback into the crank case. this would be why you seen oil comming out of the crank case vent maybe? and it would explain the hard time starting. im not 100% sure im remembering right some on else on here will correct me if im wrong.

[trizilla]

if your dumping gas into anything ( plug hole or carb) to get this to fire, your obviously not getting gas into the cylinder. how many turns out are you on the pilot?

[85burbanator]

what ever it specified in the manual. im gunna take the carb back apart to make sure it isnt plugged or anything. im gunna get some clear tubing also to check the fuel level in the float bowl.

[Lukeatc185]

compression would still make sence to me. without good compression the piston cant really pull in the fuel and air as well. so if he put gas into the back of the carb it is pulled into the cylinder alot easyer. and if he goes right to the spark plug hole its the same idea. im pretty sure the oil comming from the crank case means there is a compression issue or something along those lines.

[85burbanator]

that why im trying to adjust the valves or valve timing before i tear it open and put a new piston or rings in it. arent both marks on the flywheel and timing gear supposed to line up with the perspective stationary marks at the same time?

[Lukeatc185]

im not 100% sure on yamaha's but on hondas its. the T lines up with a marking on the cam gear that is supose to line up to a mark on the rocker cover. at this time there should be no force on your valves. they should be both closed. then you move the flywheel a little further to "F" and thats where you line up spark timing.

[85burbanator]

the is only a little hash mark on the for the flywheel. no f or t as it states in the manual.

[MonroeMike]

Before you start messing with the timing, clean the jets again.

Make sure you can see light through them, the long way.

[85burbanator]

i checked the jets and they were good and clean. i set the carb to stock specs as described in the manual (clymers) and reinstalled it. i got some clear tubing to check the fuel level and it was good. i then attempted to start the bike for about 15 minutes with no luck. she's still getting spark and i dumped some gas into her but nothing worked. i tried with both the recoil and electric starr with the same result. think the rings might need to be changed? maybe freshen up the top end and see where thats goes?

[MonroeMike]

You need to get your hands on a compression tester. Harbor Freight has a cheap one, if you can't borrow one from somebody.

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=95187

[85burbanator]

well I got the hf comp tester and the highest it read was 30psi. No good, now it has a shrader valve in the tip that inserts in the plug hole. Should I remove that and try again or is that just to hold pressure at the gauge

[MonroeMike]

The valve belongs there.

Did you hold the throttle open during the compression test?

[85burbanator]

no, it was closed. i wondering one of the valves isnt closing all the way or somethine because when it was running it seemed fine. i dont have tire on it so seeing how it acted under a load isnt gunna happen.

[MonroeMike]

Hold the throttle wide open, when you do the compression test.

[85burbanator]

so hold the throttle wide open then. and if it still reads low like that what do you think it could be? rings or valves not closing? it did sit for a while.

[MonroeMike]

Don't forget to check that the compression release isn't holding the exhaust valve open.

If it still has low compression, squirt some oil into the cylinder, do the test again, if you have a higher reading, rings are bad.

If the reading stays the same, it's either valves or a head gasket.

[85burbanator]

right on. ill check it in the morning and let you know how it goes.

thanks
mike

[85burbanator]

i did as you said and it read 60psi at the highest. it was hard to turn over but i got it lol. so the rings are prolly bad then huh

[Lukeatc185]

if you want to see if the valves are seating, remove the rocker cover and head. flip it over you will be able to see if it is seating or not. i use oil. pour it on the valves while its upside down and check to see if its leaking through. if not then its valves. or it could be a worn down cylinder wall.

[85burbanator]

I'll check the head when I get home. So if the valves are properly seated they won't leak correct

[MonroeMike]

If the compression went up after you put oil in the cylinder, the rings are bad.

You can test valves on the bike (and more), if you have a air compressor. Put the piston at TDC, compression stoke. Brace it from rotating or have someone help.

Pressurize the cylinder with air, you'll have to take the one way valve out of the compression tester hose, if you use that.

If air comes out the muffler, the exhaust valve is not seating.

If air comes out the carb, the intake valve is not seating.

If air comes out the breather, rings are bad.

If air (oil bubbles) comes out around the head gasket, bad head gasket.

I'd say, you will have air coming out the breather. If you plug the breather hole, you can then check for other air leaks.

[85burbanator]

yea I don't have a compressor unfortunatly. I've got the head off and just looking at the piston and cylender they don't look bad at all. Think I could hone the cylender and replace the rings? I might take it to a shop to get measured up and see what they think. I'm getting ready to test the valves by dumping oil on em or whatever her in a little bit and well see how that goes

[85burbanator]

i just got back from checking the valves and they seem to be fine. oil sat in the head for about an hour and it hardly moved so im thinking rings or head gasket. the head gasket is kinda bowed up by were the chain goes through for the cam gear. not sure what that means really.

mike

[MonroeMike]

My local motorsport shop mics my stuff for free. Maybe there is one around there that will check that cylinder for you.

Edit - My shop does all brands, not like a Yamaha only dealer. I went to the "dealer" once and mentioned "three wheeler" and they went back to eating their lunch. They are expensive too.

[85burbanator]

yea ive got a reputabl shop close by that is friendly. im gunna swing in there and see what they say. just wondering if everything checks out if i can just replace the rings or if i need a new piston and ring set. there is zero play in the piston when i tried to move it around in the cylinder.

just trying to keep costs down

mike

[code200k]

if all looks good you can just replace the gasket and rings

[85burbanator]

awesome. I hope thats the case then.

Mike

[85burbanator]

well just got back from the shop and they tried to hone it out but the cylinder was to pitted. i figured screw it, there gunna bore it out and get a new piston and what not. the rings were frozen in the grooves on the piston. more then i wanted to spend but id rather do it right the first time instead of doing it later.

mike

[85Tecate]

Dont go overboard on the bore job. I bored a 200 ytm out .040 a few yrs ago and it caused nothing but problems. It got really hot and ended up siezing the engine up 4 different times from excessive heat. Keep the bore minimal and you should be just fine. It didnt cost much for the rebuilt either.

[85burbanator]

yea there just goin .020 over. itll be about $200 or so when alls said and done. got the bike $25.

[85burbanator]

well i got the cylinder back and shes purdier than ever. then ended up having to go .040 over sincw the cylinder was so pitted. got a brand new wiseco piston and i dont even want to install it. it looks to good.

the only concern i have with the new piston is that its a flat top design vs. the stock one that was dished. do they do that do offset the material they remove to keep the same comp. ratio?

any tips on instaling this? never done one before. all i know is that the arrow faces the front.

mike

[85burbanator]

ok. i think im done working on this thing for awhile. everything was going awesome. gaps were good, piston slid in nice and easy, everything went together beautifully. of course as my luck would have it something bad had to happen and through a wrench in the works. when i went to put the cam chain and gear together i noticed the chain was spinning freely, great i said to myself since i had to tear it back down and put the chain back on. do that and notice the smale oring that goes on the right rear head bolt between the cylinder and bottom end was smooshed. go to the store and get another one. start to put everything back together, its all looking good, then at the last possible second that stupid f'in oring fell into the motor. i tore it back down and cant see it so its down in there. what should i do? remove the motor and tip it over to try and get it out? say screw it and get another oring? or do i have to split the case to get the trailprotrailprotrailprotrailprotrailprotrailprotr ailpro out. im so furious right now. i just wanted to get the thing running but i cant have anything easy, somethings always got to happen to screw me over. any tips on getting this oring out would be greatly appreciated.

thanks
mike

[85burbanator]

no ideas huh.

[inv3ctiv3]

Get a flash light? Hold the motor upside down and shake and hope it falls out.....

[MonroeMike]

I've done it before, I tipped it over, but my engine was already out.

Had a heck of a time, it was stuck in there, finally came out.

[85burbanator]

Ya I think I'll give it a go this weekend. Thanks guys

Mike

[85burbanator]

well I got it. It was a pain and I'm ready to toss the clymers manual in the trash. It made everything more difficult then it needed to be and half the stuff it said to do was useless. Now I just gotta get it all back together

[MonroeMike]

Glad you got it out.

[85burbanator]

thanks me to. now if i can remember how everything else went back toegether we'll be all set.lol