JW896
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Posts posted by JW896
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did you take it out of the frame?
doesnt make sense does it
The mounts on the frame are fixed arent they...not bolt on brackets?
I did pull the engine from the frame and rebuilt it. I slipped the engine into the frame from the right side, but it won't seem to drop low enough and slide back far enough to place the mounting bolts thru the frame to secure the engine...
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I have completed rebuilding the engine on a '74 DT175 and now I am trying to slip the engine back into the frame. I was able to get the top rear mount to align, but when I insert the mounting bolt, the front and lower rear engine mounts are too high and I can't seem to get the engine to budge. I took the top rear bold out and I can get a bit closer with the lower rear mount and front top mount, but it still need to shift down in front and back abotu 3/4 of an inch. I can't see any where where it is bound up. Is there a trick or technique I should be using? Thanks JW896
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Ahh I see yours is a later cable arrangement than mine and does indeed have a self adjusting cable. not sure what the issues are but just check that the pully hits the closed off position pip and peg aligned...at the same time as you hear the carb slide 'clunk' shut...well thats what i'd do.
I was going to send you a exerpt from the manual but I could'nt figure out how to cut an paste it or link it. But it sounds like you found the reference.
I did prime the pump as you suggested and confirmed that the pip and peg are aligned. It seems to run fine. A bit smoky, since I still have some mixed fuel in the tank. Now all I need to do is get the carb adjusted a bit and I am off to the dusty trails!
This bike has a Mono-Cross single shock that runs from the rear swingarm to the center of the frame under the fuel tank. It is one sweet ride and fast. It seems to be smoother than my '74 DT175 with the dual shocks in the rear. I did get the top end bored out on the '74 after breaking the piston skirt. Now all I have to do is get it re-assembled. Once I get it running it should be an interesting comparison. Thanks again for the help. I really appreciate it...
JW
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The oil light is nothing to do with pressure...or the pumps function in any way, It is there as a level warning indicator. As such it is importand you know the bulb is good and so you will find it permanently on when in neutral, it will go off when in gear as long as there is sufficient oil in the tank.
Pump bleeding...remove the small screw from the top of the pump until bubbles cease to come out and oil flows freely from the hole.
Pump priming...start the engine and allow to idle, turn the pump pulley by hand until the pump is stroking at maximum, hold it there for around 30 secs or if you have a clear oil line to the carb...untill you see no air in it.
That all makes sense because I first noticed the oil light was on when it was in neutral. The oil tank was about 1/3 full. I topped off the oil tank and started troubleshooting. I never took the bike out of neutral while I was checking out the oil pump. I did bleed the pump and got no bubbles, but I did not prime the pump by cranking the pully cable. I'll give it a try. This bike has a self adjusting cable arrangement. Do you think I need to do anything with it adjustment wise? Thanks for info!!
JW
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I recently bought an ’81 DT175H Enduro. It has about 9600 miles on the speedometer. It had not been run for a couple of years. I cleaned up the bike; cleaned the fuel tank; replaced all of the fluids except for the 2 cycle oil; replaced the plug; removed the carb and thoroughly cleaned it and made sure the jets were clear. I removed the oil pump cover plate and bled the oil pump.
I had to bump start it to get it running. I was running premium fuel (no Oil mix). The pump was activating. I ran it for about 10 minutes and ran through the gears. The bike quit and when I restarted the engine, I noticed that the red oil indicator light was lit up. I killed the engine and rolled it home. I added 2 cycle oil to the fuel and started to troubleshoot the oil pump.
I checked the minimum clearance between the adjuster plate and oil pump head. I removed one thin shim and the gap spec’ed out at .025. (The specs call for .020 to .025). I pulled the oil line from the oil pump and filled the line with 2 cycle oil and plugged the open end. I started the bike and the oil pump is pumping oil. I replaced the oil line, bled the pump again and started the bike. The red oil indicator light is still on.
So I am reluctant to run the bike not knowing whether I am getting enough oil to cylinder. I am not sure whether the oil light will go out if I keep running it with the fuel/oil mix.
I’d appreciate any suggestions for troubleshooting the pump, checking the quantity of oil output, and checking the oil indicator light.
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Yet another update:
Pretty much decided to do the work I was originally going to do before moving on, as I'm guessing I'm dealing with a seal issue.
Removed the cylinder, checked that it and piston were in remarkably good shape after cleaning the carbon off of the piston with a combination of a rounded hacksaw blade and some brake cleaner to finish things off. (Afterwards, of course, cleaned all chemical residue, oiled things up and loose fit things back together.) I may end up checking the timing with the head off - undecided as yet.
Replaced the left crank seal and checked the points closely and looked practically brand new. I have a vague memory of replacing them sometime in the mid to late 70s, but had no idea it was so soon before I parked it. The left seal was easy to replace after drilling a pilot hole and using a sheet metal screw to extract it, but needed to get a new Phillips bit for the impact driver to get the stator assembly out to access the thing (I think I ended up using a #2 for future reference after mashing one screw to oblivion with the wrong bit). If anyone knows an easy source for stator screw replacements it sure would save me time.
I started to do the left seal, but found out I don't have a long enough Phillips impact driver bit to take off the screws on the right case side. Those puppies are in there wicked tight and when I started to round one I decided to wait until I can get my hands on the correct tool so that I don't end up replacing every silly fastener on this engine.
Ah well. It will give me something to do over the weekend. I'd rather be riding all weekend, but without doing this work I might end up pushing instead and I've had enough of that for a while.
Update 7/24/10 6:20pm EDT
If anyone is curious, a #3 Philips Screwdriver and a hammer to tap on the right crankcase screws when its in there along with some significant elbow grease is enough to get the screws out. If you try something smaller, you're more than likely going start rounding out a screw or two.
(I found this out after driving more miles than I care to mention and then giving up trying to find 4 inch long #3 hand impact bits and decided to take a risk.) Of course the screws were all slightly rusted at the point where the cases actually meet but nothing horrible.
Once the screws were out, got the right cover off after rapping it a little with a rubber mallet. A few thin shards of what were probably once the edges of gears in the bottom of the case (hopefully benign, since there have never been transmission issues).
Now off for some more disassembly to replace the right crank seal and O-ring. I'm taking pictures, but can't figure out why they never show on the site even when think I followed the instructions in the FAQs, so I'll give up on trying for a while.
Hopefully some good news that I'm finished later.
I had problems removing the Stator plate screws on my DT175. I ended up drilling the center out and then jambing a flat screwdriver bit into the center hole to extract them. I got them out but they were pretty much toast. I happed to be at the Yamaha dealer and asked if they had any replacements. I was able to replace them with identical screws however they tighten with an allen wrench rather than a phillips bit. The previous owner of my bike had rounded out a couple of the coverplate screws. I was able to replace them with one of 3 options: either a phillips bit screw, an allen wrench head or an 8mm bolt head. They had all of the required lengths. JW896
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Well, I'll give the photos another shot later on today when it's calm. Every time I think I have a few brain cells that still work, something like that comes up to put me in my place.
I went to the FAQs originally when I tried to post a picture of my "rusty, then clean" tank in the Bar area and I thought I had everything all set. Got a Photobucket account, copied the pic "img" info into the body of the post, but all I got in the post was the address. However, when Vez replied, the picture was magically there. I'm sure it's just something stupid I've done, however, and I'll check it out later on.
Re the gasket, the heat gun would have been my first choice as well, but I'd loaned it to my brother to take some old window glazing off, and I was too lazy to go and fetch it.
I did think it was slightly odd to have gasket cement there, but some sections were sure stuck on there. I didn't really notice a huge amount, but they were practically welded in place in some sections, so figured it was cement.
I shared your saga with my brother. He has reconstructed a number of vintage bikes. Here is his comment/suggestion:
"I had one just like this, I bet there is a restriction in the exhaust system, he should try running it without the exhaust system, I bet the back pressure is the issue. Perhaps a wasp next somewhere in the pipes. I had to cut mine open to find it." Might be worth a try. JW896
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It's interesting, I saw a link on youtube titled Removing Flywheel covers. The guy takes a rubber mallet and gives a short whack on the rim of the flywheel then turns it a bit, does that about 20 times and it pops right off. Since I can't locate a tool on Sunday afternoon, I figure I'll give his technique a try. I had let the crank spindle soak in penetrating oil. I wiped down the flywheel and heated it a bit with a heatgun. After about 20 whacks it popped loose. So now I'm back in business. I am headed out to open up the crankcase and clean it up. I'll keep you posted. Thanks for the advice.
JW896
OK now that I have the flywheel removed, I can access the crankcase bolts and I successfully removed all of them. I checked the manual and started removing parts systematically. I have run into the next jam-up. No problem until I got to the removal of the primary drive pinion center nut. The manual does not specify whether it is RH or LH threaded. I heated it, shot it with penetrating oil, and tried whacking the wrench in both directions with no luck (multiuple times). I can't see enough thread to see whether it is RH or LH treaded so I don't know which to direction to direct my efforts and I dont want to damage the nut. It won't budge. I tried the impact driver with a 19mm socket (both directions) no happiness... I have ceased the heating and beating, any suggestions are most appreciated...
JW896
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sorry it's slang for 'proper' puller
It's interesting, I saw a link on youtube titled Removing Flywheel covers. The guy takes a rubber mallet and gives a short whack on the rim of the flywheel then turns it a bit, does that about 20 times and it pops right off. Since I can't locate a tool on Sunday afternoon, I figure I'll give his technique a try. I had let the crank spindle soak in penetrating oil. I wiped down the flywheel and heated it a bit with a heatgun. After about 20 whacks it popped loose. So now I'm back in business. I am headed out to open up the crankcase and clean it up. I'll keep you posted. Thanks for the advice.
JW896
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yes ok that makes sense to me. you should not really be risking a 2 arm puller on the flywheel, pukka pullers are so much better, cheap too.
Agreed. After looking for parts and seeing the prices I decided to find the right tool for the job. Sorry for sounding like a nubie but what is a pukka puller?
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puller is 27mm lh thread yes, available from yambits wemoto no name but a few, how come you havent filled your profile in...where are you?. These are in UK
seals can be got out sometimes by drilling a small hole in opposite sides then screwing a self tapping screw in and pulling on it. Personally I havent tried this but I can see the attraction of not having to strip the motor down completely.
Just updated my profile info. I am in the US - out west in Idaho. I have a Haynes Workshop Manual. It's a good manual with lots of useful pictures, but no specs on the flywheel puller. I was able to make a few modifications to a 2 arm puller, for the first couple of times I pulled the flywheel. Teh flywheel has gotten pretty stubborn and I don't want to run the risk of damaging the crankshaft. I am have the engine pulled so I set it on it's side and I have some penetrating oil around the shaft to hopefully help the cause. I took the cylinder and old piston to the Yamaha shop and they are going to rebore the cylinder. I have a set of gaskets on order, so in the meatinme I am planning to open up the crankcase clean out the old piston fragments and check the bearings. The Yamaha shop suggested replacing the main seals and hold up on replacing the kickstarter and shifter seals since these can be replaced without opening up the crankcase again. Does that make sense to you?
JW896
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Paul - I am running into an issue pulling the flywheel. Can you confirm that it takes a 27MM x 1.0 left hand threaded puller? Thanks JW896
I also read the long thread on the CT175 and got to the part about removing the crank seals. Are there specialty tools for that or tips. Sounds a bit tricky...
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As it's now in bits
I would recommend replacing the crank seals, gear shaft seal and kicker shaft seal.
Mainn bearings?? give them a good clean and feel for roughness or free play, replace these too if there is any doubt.
Paul - I am running into an issue pulling the flywheel. Can you confirm that it takes a 27MM x 1.0 left hand threaded puller? Thanks JW896
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Hi, I am no expert by any means so don't trust this without confirming, but if you can get all the bits of piston out from round the crank flywheel then you might get away with just a top end strip down. If the crank is jammed or you are worried that bits have got in the main bearings then you will have to split the cases, if you are doing that then you may as well re-new all the bearings and seals which isn't that expensive, in parts. Main bearings may not come off that easy and you may need help with that, otherwise not too hard. If you ring Granbys they will tell you what you need.
Good Luck
Phil
Thanks Phil... a lot of fragments dropped into the crankcase and to be safe, I am going to open up the case. I did some checking and I am planning on replacing the seals. I want to inspect the bearings before I pull the trigger on them. JW896
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I have been retoring a '74 DT-175A. It had low compression. I got it started and ran it for a few miles on the hopes that I could free up the piston rings and improve the compression. Things were going well until the kick starter locked at the low end of the stroke. I pulled the engine and found that the piston skirt had broken off and pieces were locking up the piston rod. I have it in the shop to be rebored, but I am wondering what other parts (seals or bearings) I should replace as long as I have the engine torn down? There does not appear to be much wear. Any advice would be much appreciated. Thanks JW896
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In the short term squirt some 2 stroke oil in the spark plug hole. Then try bump starting it.
If you get it running and still continue to get 70psi compression you will have to strip the top end and check the ring end gaps, it may need new rings. It may even need a re-bore.
oldgitabike - I took your suggestion only I used some Marvel Mystery Oil and got it started. Ran it for a few miles to try and free up the rings, but I ran into two problems before I had a chance to recheck the compression: (1) I can't seem to get it to shift into neutral. Not sure what would cause that problem. (2) The kick starter locks at the lower end of the stroke. I checked the manual and I should be able to get to the clutch through the clutch plate, except the bolts were frozen, so I pulled the engine. I have the crankcase opened up I am proceeding with the diagnosis. As long as I have it torn down do you think I should pull the head and cylinder to check the piston and rings. Any other suggestions for things to check as long as I have it dismantled? What would I need to check to see what causes the failure to shift to neutral?
Thanks
JW896
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As a rough guide read this
Specs for your bike will be in a manual for your bike, although I dont suppose they will be much different
...Paul
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oldgitonabike - I'll give your suggestion a try. How would I tell if I need a rebore? Thanks.
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In the short term squirt some 2 stroke oil in the spark plug hole. Then try bump starting it.
If you get it running and still continue to get 70psi compression you will have to strip the top end and check the ring end gaps, it may need new rings. It may even need a re-bore.
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I have a '74 DT175 Enduro that had been stored in a barn for many years. It had limited spark, so I replaced the plug, pulled the flywheel and cleaned the magneto and Stator plates, and I cleaned points and condenser and all of the electrical contacts. I got decent spark after all of that. I pulled and cleaned the carb (it was not too bad). After all of that I could not get it to fire. I checked the compresssion and it tests out at 70. So any suggestions for next steps?
DT175 Engine Remount Problems
in Yamaha Workshop
Posted
Correct the mounts on the frame are fixed. I am scratching my head. It came out pretty easily...