alan_nc

Jon/Majesty, I think you will find the DT piston ports are exactly the same - at least that's what my caliper said, and crank bearings are just a standard industrial bearing. Piston pin even has the same number. Crank (big end pin) I did buy from Yamaha. If you are looking for original parts try these guys, they have had everything I have ever wanted (and at a discount price). www.boats.net/parts Now Jon: Your comment about a rattle in a rebuilt engine interests me. I have two '74, TY250's, both rebuilt with the same parts (and care). Both seem to be well balanced and don't vibrate bad at all.... but all that said one has a low end rattle at times. Doesn't do it all the time. Sure would like to know what causes it. Alan

I just did my 74 TY250. Piston, piston pin, rings, top and bottom rod bearing, crank bearings, and seals. Cost about $80 total (about 160 pounds). I did everything my self. It really isn't that hard if you take your time, read all of the instructions and ask questions. You do need the use of a press to take the crank apart and put it back together (I used a 15 ton hydraulic which worked fine). Hint: Crank bearings and seals are just "off the shelf" items. Get the numbers off of them and you can get them from any industrial supplier for under $5.00 each. I found a piston kit on Ebay for a total of $24.00 shipped to my house (piston, pin, clips, rings). Remember you don't need a TY piston, several other Yamaha units work. Oh, and check your bore carefully - unless you have some special problem I'd be surprised if you need a bore job. Now I'm slow but I did have 40 to 60 hours of work in the job (from putting the first wrench on the engine to riding the bike down the drive). Other than the press I don't have any special tools. Good luck.... it's a fun project. Alan

Group, Someone asked about a clutch connection to the engine on a TY80. Can't find the post or PM. Please ask again if you still need a part. http://i226.photobucket.com/albums/dd165/A...pg?t=1241901628 Some of the TY80 parts I have (gas tanks are gone). Alan

I've got several TY80 engines laying around. Where are you located? Alan

I don't know why we don't send Beano his trophy now...... then we won't have to worry about the "Grand" champion. Alan

Wow three Lampkins in the top 30. Dougie still clean after two days. Alan

Dean, Thanks for posting the information in such a quick fashion. Question: Bottom line, is it Novice or Amateur "3. Equipment and Classification: a. All motorcycles are required to be fitted with adequate mufflers or silencers and U.S. Forest Service-approved spark arresters, as required at certain events. b. A number plate bearing the rider

Super video, thanks so much. Can someone explain the scoring to me. Looked to me like everyone had a foot down several times. Alan

Tom, Thank you. There are a lot of us out here that would like to see the complete results. Anybody have any idea where/when they will be posted. Alan

Dean, Is it to early to ask what format you will use at Mid-O? Stop or No-stop? Will you include 80ies bikes? Twin only or early mono's? 3 x 8 or 3 x 10 (sections)? Observers or peer scoring? Anything else that would help us prepare. Thanks Alan

So, on a more important note: Who is going to be Trial Master at Mid-O? Alan

I've got 2 , 74 TY80 rear wheels and both are 32 spoke. Reason people didn't answer is IT"S SUNDAY during Trials season....... Alan

This company has had everything I have ever needed. www.boats.net/parts/detail/yamaha/ Alan

Flymo, Here is the cost of new inner tubes (which I would assume is the problem). Search Results 1. Yamaha TUBE,INNER 1 434-23124-00-00 Price: $81.09 Product Name: Yamaha TUBE,INNER 1, Product ID: 434-23124-00-00, Price: $81.09. www.boats.net/parts/detail/yamaha/Y-434-23124-00-00.html - 38k - If they are pitted or rusted , and not bent, there is always the apoxy route. Several friends have used it with good success. Alan Alan

Go to the Yamaha parts list (You do realize that all Yamaha parts are shown by number/year/model, with a blow up diagram). Check DT's , TT's , MX's of the year you have (plus or minus a couple of years). The DT's share quite a few parts and are much more available. My bet is that something else will fit. Alan

There are a couple of TY250 air boxes on Ebay U.S. right now. Don't know if the shipping would kill you or not.

This news is on several sites. I think AHRMA has probably had it. Between the legal issues taking most of their money and the internal politics forcing bad decisions their days seem to be numbered. As to Mid-O: Having ridden the course a couple of times, it's a great area for a Trial. If ITSA comes in and sets up a class event we would all benefit. I like their rules better anyway. I know Bob stops by here from time to time.... come on.... step in and give us a good event. Alan

Have been trying to find the right shock springs for my TY250. Have a couple sets of shocks with good dampening and am trying to find the spring that would go with my 160# weight. I have three sets of springs: The wire size seems to determine the spring rate: .280 wire in the spring give it to much rebound (bounce). .260 works o.k., .240 also seems to work o.k. Does anyone know how they rate springs? Also.....does it make any difference if you run the shocks inverted? This would clear the exhaust better. Thanks in advance. Alan

While we are talking "Trick Mods" When I bought my TY250 the guy gave me a DG exhaust can. Replaces the spark arrester and rear part of the exhaust. Any advantage to putting it on the bike? Alan

I think you have two seperate problems. You mention changing seals - did you replace the bearings at the same time? If not, did you check the clearance on the big end and small end bearings when you had it apart? You can narrow down the location of the knock with a stethoscope - take the side covers off, start the bike, put probe on different areas (there will be no question when you find the spot). If you don't have a scope a wooden dowel about a foot long held against different areas with the other end pressed to your ear will work. 1st guess on the starting problem is: Carb needs a complete cleanout. 2nd guess: Points are burned or not set correctly. If the seals were not installed correctly you could be leaking enough air around them so that you are not pulling fuel through the carb. Good luck Alan

Jon, Thanks, I agree. I have tried to find 15 or 20 weight oil with no luck. None of the auto parts stores around here sell single weight oil except 30 weight. Didn't even find any on-line. Can you point me to a source? Alan

feetup, Well tried your idea first. Seems that I didn't have enough oil in the tubes (added several cc's to bring it up to the 125mm below top). Put a 5mm or so washer in each tube and brought the level up. Seems to be working fine. Will have to do the ole wheelie over a log and come down fairly hard to see if it is truly fixed. Stayed with the ATF that I had in the tubes (I'm about 160# so don't need to much dampening). Don't have a Trial for a couple of weeks so have plenty of time to test it. Alan

Well if the carb work didn't fix the problem do the old wd40 trick. Take the side covers off, start the bike (your going to flip some oil around). As soon as the problem starts spray the seal area with wd40 ..... if the problem goes away you need to replace the seals. I would also try this around the carb and intake boot area - you may have a leak. Alan

Group, So my forks bottomed out a couple of times in the Trial this past weekend. I'm assuming the springs are old and a little weak. Planning to put some spacers in. Do I: Put in a couple of 1/16" washers or put in a 1" plug? What I'm asking is how much shimming do you do? Second part would be how do you know when you have shimmed enough? Thanks in advance. Alan

Well I rode the 74 TY250 in it's first Trial (with me). Beautiful day, 60 degrees and sunny. The bike was a joy. Never a complaint, never a hiccup. Pulled good in all gears. Running the waited flywheel and very low gearing so I could creep through tight turns. Not a lot of back pressure to slow you on the steep down hills. Started first kick every time (well as long as you turned the switch to the on position). Bad news: Going over about a 24" fallen tree I mis-did and ended up coming straight down on the skid plate , which cracked (seems to have spared the cases), and bent the shift lever into a pretzel. Had put a set of worn tires on which slid a couple of time (will replace before next event). Forks bottomed out a couple of times. Will go back to heavier fork oil (have ATF in now), and may put in some spring spacers. Cracked both front and rear fenders, bent the tail pipe. Chain came off and broke a piece out of a perfectly good side cover. Rider was sort of bent and cracked before the event. All in all a great day, both rider and bike can probably be repaired before the next Trial. Alan