Jump to content

1980 DT175G Running Problems (US Model)


This post is 3660 days old and we'd rather you create a new post instead of adding to this one. You can't reply in this post.

Recommended Posts

Italian tune up then ( aka rev the shit out of it every gear for a 1/2 hr ),and clean the ex pipe( u tube the video of burning a pipe clean ) if the plug is black and wd40 did nothing your bike is loaded up with dinasours.

Link to comment
Share on other sites

Do you want an ad-free experience? Join today and help support the Yamaha Owners Club.
  • Moderator

Burnt the pipe out?

You do realise you need 900 odd degrees to loosen carbon. For the rear pipe (the thin bit) a 3ft length of garden hose gets rid of 80% of the blockages.

Caustic oven cleaner in solution is the er? solution. Seal the engine end with a steel plug. NOT aluminium.

Then fill the pipe with caustic (BE VERY CAREFUL, BURNS) then leave for a few days then drain.

Follow the cleaners instruction for disposal, its basically the same junk as the oven anyway. Then you will have a much cleaner pipe.

Link to comment
Share on other sites

  • 1 month later...

Well I have changed the stator side crank seal and O-ring that's seats the carb main jet. I have also cleaned out the exhaust pipe (it was pretty clean to be honest as the bike has only done 3,000 miles from new). Last job was to check the carb rubber - no leaks their. My bike is running a little better in the low rpm stages but it still hesitates right around 5000 rpm (its all good after 5000 rpm). I am still unable to get it to tick over. Should I go ahead and look at buying a used stator or do any of you fella have any other ideas?

Thanks

Link to comment
Share on other sites

  • Moderator

......... Should I go ahead and look at buying a used stator or do any of you fella have any other ideas?

Thanks

Havent you tested the stator coil ohms readings yet then?

I asked about an exhaust restrictor yonks ago and dont recall you responding about that, i linked you to a picture too and you said you would check at weekend...3 months ago?? Its hard enough diagnosing these problems just on a forum, even harder when suggestions arent followed and replied to

Link to comment
Share on other sites

Sorry about that Airhead - My pipe does have the restrictor in it.

I am not very good with electrics - which coil should I be concerned about and how do I test it? (I only have a very simple cen-tec seven function digital multimeter).

One other thing I noticed before and now after I replaced the crank seal is a whining or whuring noise coming from inside the stator crank case cover. I can only hear it when the bike is cold. It disappears after around 30-60 seconds.

Link to comment
Share on other sites

  • Moderator

Sorry about that Airhead - My pipe does have the restrictor in it.

I am not very good with electrics - which coil should I be concerned about and how do I test it? (I only have a very simple cen-tec seven function digital multimeter).

One other thing I noticed before and now after I replaced the crank seal is a whining or whuring noise coming from inside the stator crank case cover. I can only hear it when the bike is cold. It disappears after around 30-60 seconds.

dont like the sound of the whining noise you reported, you really should investigate this before any damage is done, is there any lateral play in the magneto rotor? The magnets only just have clearance from the iron cores of the magneto coils, very little clearance! If something isnt right then the magnets can rub against the iron cores and if this is allowed to go on then heat is generated through friction and the coils concered can burn out...I've seen it several times and I hazard a guess that it's down to 'have a go Henry' not torqueing down his rotor nut to the specified torque 40 lbf ft.he got his mate to hold it best he could and just tightened it a bit best he could !

To me this is more important than any other issues at the moment, did you torque it down properly then, with a click stop torque wrench?

Link to comment
Share on other sites

I did not notice any lateral play in the magneto rotor and yes the magneto was torqued down correctly to 39.5 ft. lbs. with a very good quality torque wrench. I better whip the casing off and have another look. I will let you know what I find out. Thanks

Link to comment
Share on other sites

I just posted a load of Flickr links off my mag and stator. I did notice some where on the magnets on the inside of the mag (see pics). The ends of the coils are also worn in places (see pics). Everything was still tight when I removed the side case. How does it look?

Link to comment
Share on other sites

I do not know how to attach pictures to a post? Their is a groove in one of the magnets and burring on the edge of the source coils. I am not sure how it got there? Their is no up and down or side to side movement when you grab hold of the magneto. If you remove the magneto and grab hold of the shaft you can feel the tiniest bit of up and down movement and Zero side to side lateral movement.

Link to comment
Share on other sites

  • Moderator

you shouldnt be able to feel any movement at all, I presume you need new crank bearings it's possibly this that has caused that groove and the noise you are hearing.

Perhaps you can prove this by painting the edges of the coils with something like tipex correction fluid, re-assembling and run it again

notice if you still hear the noise, and pull the flywheel off again and see if the correction fluid coating has been worn away?

To attach pictures, upload them to your photobucket account and copy the img tags, then paste into your post

Link to comment
Share on other sites

Thanks for the tip on posting photos. I like your tipex suggestion. Going to give it a try. I have never noticed any oil coming from the mag side oil seal. It is dry as a bone. Going to mess with it again now.

Link to comment
Share on other sites

I must have been hallucinating yesterday....just tried the shaft again and their is zero okay up and down. The bike has had a very easy life and it only has 3,000 miles on the speedo. I am going to put it back together right now. I will reply shortly. Thanks for the help and advice. I love this little bike, I just want to get it running right!

Link to comment
Share on other sites

Flywheel has been removed. Used the kicker to test on all four angles - I found zero play.

The climate down here is right for bikes. If you ever need anything let me know. I have shipped many a bike and bits back home. Glad to help anyone out.

fettling with it as we speak.

Link to comment
Share on other sites


  • Who's Online (See full list)

    • There are no registered users currently online
  • Recently Browsing

    • No registered users viewing this page.
×
×
  • Create New...