revenger666 Posted June 3, 2009 Author Share Posted June 3, 2009 As far as torque specs the barrel base bolts (4of) are 29 lbf ftn with the cylinder head nuts (6of) at 15-18. Barrel base I'm assuming is the bottom end where the cylinder/block meets the crankcase? If that gasket were bad, the bike should still run though, correct? I don't think the bottom end would see any compression, if that gasket were bad, wouldn't I just leak oil? Link to comment Share on other sites More sharing options...
Moderator Airhead Posted June 3, 2009 Moderator Share Posted June 3, 2009 Barrel base I'm assuming is the bottom end where the cylinder/block meets the crankcase? If that gasket were bad, the bike should still run though, correct? I don't think the bottom end would see any compression, if that gasket were bad, wouldn't I just leak oil? Hi Matt Yes Cynic is referring to the cylinder base gasket, it does need to be in good condition as a 2 stroke engine uses crancase compression to transfer fuel / air into the combustion chamber, if that gasket were bad then crancase compression would be less than ideal. you would not however leak oil in any noticeable amount because the oil is a trace quantity mixed with the fuel in this part of the engine. ...Paul Link to comment Share on other sites More sharing options...
revenger666 Posted June 4, 2009 Author Share Posted June 4, 2009 Well, I did the gaskets, and she still doesn't fire up. I guess that leaves me with the piston rings being shot? What else could it be? Like I said in the first post, it gets air, fuel, and spark. I can get it to spit once, usually only on the first or second kick, then nothing. And if I feel the block, it'll be warm. The thing is, if I put my finger over the spark plug hole and kick the engine, it doesn't come close to pushing my finger off, and I think it should be able to push it off fairly easily. Would it be better if I tried getting a video and posting it up so you guys can try diagnosing it better? If it is the piston rings, is it even worth it to try fixing or should I just look at buying a "new" (used) engine? I'm not too familiar with doing piston work. Thanks again for all the help so far, I appreciate it. Link to comment Share on other sites More sharing options...
TylerP Posted June 4, 2009 Share Posted June 4, 2009 The finger-over-the-hole trick is not the best way to check compression but yes,it should give a healthy PFFFFFFFFFT! Thats a very easy bike to take apart & work on. You should find a compression tester and try it that way. Also,be sure to hold the throttle wide open while checking it. Under 100 lbs and it's top-end time. Link to comment Share on other sites More sharing options...
JimR Posted June 4, 2009 Share Posted June 4, 2009 Well, I did the gaskets, and she still doesn't fire up. I guess that leaves me with the piston rings being shot? What else could it be? Like I said in the first post, it gets air, fuel, and spark. I can get it to spit once, usually only on the first or second kick, then nothing. And if I feel the block, it'll be warm. The thing is, if I put my finger over the spark plug hole and kick the engine, it doesn't come close to pushing my finger off, and I think it should be able to push it off fairly easily. Would it be better if I tried getting a video and posting it up so you guys can try diagnosing it better? If it is the piston rings, is it even worth it to try fixing or should I just look at buying a "new" (used) engine? I'm not too familiar with doing piston work. Thanks again for all the help so far, I appreciate it. Hi, can you confirm which bike you are having problems with a DT or WR ? Regards Jim Link to comment Share on other sites More sharing options...
revenger666 Posted June 4, 2009 Author Share Posted June 4, 2009 The finger-over-the-hole trick is not the best way to check compression but yes,it should give a healthy PFFFFFFFFFT! Thats a very easy bike to take apart & work on. You should find a compression tester and try it that way. Also,be sure to hold the throttle wide open while checking it. Under 100 lbs and it's top-end time. I agree with you on the ease of taking things apart and working on them, but it's finding replacement parts that isn't easy. I'll see if I can get my hands on a compression tester, and go from there I suppose...this is going to suck if I have to pull the head again, what a waste of a brand new headgasket can you confirm which bike you are having problems with a DT or WR ? DT175 Link to comment Share on other sites More sharing options...
Moderator Airhead Posted June 4, 2009 Moderator Share Posted June 4, 2009 ..this is going to suck if I have to pull the head again, what a waste of a brand new headgasket Not so, its a copper gasket so heat it with a blowlamp, (anneal it), then re-use it, I have done this many times without any problems. Link to comment Share on other sites More sharing options...
revenger666 Posted September 24, 2009 Author Share Posted September 24, 2009 Hey everyone, I wanted to bring up my old topic again because I have brought my project back into the light and decided to work on the piston rings. I did the "add-oil-to-the-cylinder-and-see-if-you-get-better-compression" piston ring test and the bike actually ran for a few seconds. So I decided to pull the head off again and the cylinder block as well so I could get to the rings and see what kind of condition they were in. They seem to be in good condition, just stuck to the piston (gummed up). I did some research and found using stuff like PB Blaster, WD-40, ATF, and Marvel Mystery Oil can help free up rings, so I hit them with some PB and WD-40, but I think the best way to do this is to let the piston sit in a small container with some of this stuff (or MMO or something). I was looking at a manual and after looking at the piston, I see the wrist pin is held in with a few snap rings (circlips as the manual called them). The manual said not to reuse them after pulling them out and to put in new ones each time. My questions are: where the heck can I find new "circlips"? The hardware store? And do I really need to run new ones or is the manual just saying to use new ones for the hell of it? Also, if you have any other ideas for trying to free up gummed up rings, feel free to share. Should I hone the cylinder after freeing the rings even though they aren't new? And is ebay the only place (besides Yamaha) to get new piston rings? I can't find them anywhere else (I may want to source new ones just in case something happens with the old ones) Thanks in advance, and sorry for the long post and for the revival of a somewhat old thread -Matt EDIT: I will be giving my "local" Cycle Design a call within the next few days, they may have what I need, but I have been told they can be a bit expensive, so if anyone knows other places that may have decent prices, feel free to post them up. Link to comment Share on other sites More sharing options...
JimR Posted September 25, 2009 Share Posted September 25, 2009 Hey everyone, I wanted to bring up my old topic again because I have brought my project back into the light and decided to work on the piston rings. I did the "add-oil-to-the-cylinder-and-see-if-you-get-better-compression" piston ring test and the bike actually ran for a few seconds. So I decided to pull the head off again and the cylinder block as well so I could get to the rings and see what kind of condition they were in. They seem to be in good condition, just stuck to the piston (gummed up). I did some research and found using stuff like PB Blaster, WD-40, ATF, and Marvel Mystery Oil can help free up rings, so I hit them with some PB and WD-40, but I think the best way to do this is to let the piston sit in a small container with some of this stuff (or MMO or something). I was looking at a manual and after looking at the piston, I see the wrist pin is held in with a few snap rings (circlips as the manual called them). The manual said not to reuse them after pulling them out and to put in new ones each time. My questions are: where the heck can I find new "circlips"? The hardware store? And do I really need to run new ones or is the manual just saying to use new ones for the hell of it? Also, if you have any other ideas for trying to free up gummed up rings, feel free to share. Should I hone the cylinder after freeing the rings even though they aren't new? And is ebay the only place (besides Yamaha) to get new piston rings? I can't find them anywhere else (I may want to source new ones just in case something happens with the old ones) Thanks in advance, and sorry for the long post and for the revival of a somewhat old thread -Matt EDIT: I will be giving my "local" Cycle Design a call within the next few days, they may have what I need, but I have been told they can be a bit expensive, so if anyone knows other places that may have decent prices, feel free to post them up. Hi Matt you should use new circlips of the correct type as if they come out when the engine is running the result could be real bad ! would this bike be circa 1977 or later as at this point of time the E was the 12v electric start version (UK only had DT125E but other parts of the world had a 175 version) ? Regards Jim Link to comment Share on other sites More sharing options...
Moderator Airhead Posted September 25, 2009 Moderator Share Posted September 25, 2009 Hi Matt you should use new circlips of the correct type as if they come out when the engine is running the result could be real bad ! would this bike be circa 1977 or later as at this point of time the E was the 12v electric start version (UK only had DT125E but other parts of the world had a 175 version) ? Regards Jim Hi Jim, youve been quiet lately, The E is not an elec start to my knowlege, its the same or similar to our MX like mine... Link to comment Share on other sites More sharing options...
JimR Posted September 26, 2009 Share Posted September 26, 2009 Hi Jim, youve been quiet lately, The E is not an elec start to my knowlege, its the same or similar to our MX like mine... Hi Paul, I have been in Eygpt for 2 weeks & prior to that I was given a large project at work so my time went into that .... it's just the E bit throwing me Regards Jim Link to comment Share on other sites More sharing options...
revenger666 Posted September 26, 2009 Author Share Posted September 26, 2009 Hi Paul, I have been in Eygpt for 2 weeks & prior to that I was given a large project at work so my time went into that .... it's just the E bit throwing me Regards Jim I think the "E" was just the next letter in the production model year (lol, not sure how to describe it) Bike VIN Data Check out that link I came across a little while back, they matched up VIN #'s to models, year, etc. The DT line is on there. Not sure how accurate it is, but my VIN matches up for 1978 DT175E. It doesn't have electric start, it's kick start only And thanks for the heads up on the circlips. I went and bought a couple. Link to comment Share on other sites More sharing options...
JimR Posted September 26, 2009 Share Posted September 26, 2009 I think the "E" was just the next letter in the production model year (lol, not sure how to describe it) Bike VIN Data Check out that link I came across a little while back, they matched up VIN #'s to models, year, etc. The DT line is on there. Not sure how accurate it is, but my VIN matches up for 1978 DT175E. It doesn't have electric start, it's kick start only And thanks for the heads up on the circlips. I went and bought a couple. Hi, ah a 2A7 bike that now makes sense as a DT175MX. In those days Yamaha used a strange system ... in certain parts of the world the bikes were sold via the letter (i.e DT175E) and in other parts of the world by another title (i.e DT175MX). As to gummed up rings (which I guess you have sorted) gently prise out the rings from their grooves and use a screwdriver to clean out the grooves in the piston and clean the rings and refit ... as they are off the piston it would be a good idea to check the end gap of the rings just to make sure they are not worn out. Regards Jim Link to comment Share on other sites More sharing options...
popalong Posted November 11, 2009 Share Posted November 11, 2009 No, with respect they are very much different bikes, they have a similar 'family' look but not a lot else. Link to comment Share on other sites More sharing options...
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