Trials Australia Forums

I think I will have to leave it and get some more 400. If it wasn't for the scratches at 3 o'clock I would leave it at that


Sheet of glass and 400 grit wet and dry

Progress is slow


I want to give this bike some aspects of a trials bike.


I work on this one like a race bike.


This model has some history. End of the air cooled. Electric start with no kick starter. That suggest confidence in the starting system.

I bought it as not going apparently it wouldn't start I did some research and came to the conclusion valves to tight. Common reason for not starting and feasible for 3000 k.


So pulled it down and scrubbed the farm off it. He said he bought it off some bloke and had a piston put in it. Why a piston at 3000k. Some thing about that's what you always do with a 2 stroke. I can see that. That gasket ossing red goo is still wet. Strange how you can listen to some one and not hear what they stead. No it's not the drying type. Fair enough so I gave him $1,200

3000 kilometres how bad can it be man that bike looks at the upper edge of 3000k's
Missing starting plunger, two stripped minor head bolts. Helli coil in the left head bolt. There are 2 helli coils in the left head bolt, the bottom one is in so deep the tag is still in place. Some thing must shave gone wrong with putting in the second as the head bolt will only wind in the length of the head bolt which is why it has half the thread. The rest was cut off. Which could explain why it was loos to start with.
The head gaslit looks like it was scrawled off with a old paint scraper.
Sleazed plots
Gaslit shit every where if it was under preacher it's solidified or if not its gunk.
Obviously reusing gaskets. What does that say.
I think it's been a interesting 3000ks.
Some good points are Reathal bars, hand guards slip on

It's going back together with MX pipes modified, enduro cam, half manual CV carb (not my choice at this stage) air box mods

It's hard to post with a iPads. Strange things happen


I edit my posts and put in more information but then loose it?


So

Torking those bolts down was nervece. And I got my fear, two of them went soft.

Uhr Google options, Engineers shop, which one, what's the options, how much.


Nice guy, asked i have some new bolts. I had to pay a small amount extra because it took 3 x as long. They will remember me.


It had better work. I can feel his frustration and the last thing I want is to take it back broken.


Before when I put the barrels on I noticed the piston ring was stuck in place in one spot. Further inspection reviles that the excess red gasket, hardening under lode goo had made its way into the top ring grove and cemented its self in!

Oho joy

The barrels are on again and I was just lining up the new but half crushed once after market head gasket and noticed this.


Off course I can now take the side cover off again because I like reusing once crushed never used gaskets.


My mate had suggested several times I should look into the oil pump. You have still not found that small decompression pin.
Strange how I have to take the oil pump off to put a new cam chain on.

Seems it has had a play with the cam chain on the way down. Any chance it's in the oil pump!!!


When I get this going and had some use with it. I think I will get it road registrable again and may take it on special events.
I have a plan. I'm going to need to make a pretty special fork brace to hold the mudguard in that place.


I have already started on the motor. It may not be a big one but if its happy they are all fun to ride

This model has a air bleed into the exhaust port to burn off the last of the fuel.
I had plugged up one side By dremmiling out the opening, drilling, taped, chopped off a bolt and turned into a grub screw and lock tight in.
The other side had a Devcon bunged up hole that I had left as it was. Now that its off again my nagging feeling of. If one side was open changes are it used to be bunged off but blew out. What's the changes that the other side may go some time as well.
So I took the opportunity to permanently close it
Shame about the scratch. But it does not matter in any way.


I bought a jet kit that took a while to arrive and now that I can put the motor together. I discover the jet kit is for the normal models and not my odd one that never should have come to Australia. Seems the jets are my size and five grades smaller. They agreed to send a mother set five grades larger and I will enjoy the delay.

This is the offending pin that I think caused cam chain damage? Not that I know what the previous "mechanic" had done


I am so lucky I accidentally spotted that. If the head bolts had not gone soft when doing them up. I'm sure it would have failed at a very inappropriate moment.


I could not find the pin


Nor is it in the oil pump.


If its in there some where its probably waiting for the right time to strike.

When I was putting on the head I noticed it didn't want to go down on the dowels. Seems the problem was way I thought was a good dowel wosnt. It says jammed in with gasket gue,misting askew and high. This would have throne the mâché nest off on his measurements. Lucky I ordered a new one as seen in the photo.
The new one piece thread and dowel measured on the border line of beeping to high and may prevent torquing down and consequence Leakey head gasket.
The one in the picture has already been shaved by one or so mm


Didn't want to take the barrel off again so lowered it like this


The aftermarket gasket has a big gap between the boar edge and the crush ring. I haven't done the maths but I suspect its quite a lot of compression loss. Must be a one size fits all thing?
I never noticed that the file marks are so rough till I looked at the photo.


The OEM gasket is perfect.
Why would a 12 year old motor that had done 3000k need a new piston?


This is the part I'm nervice about. I'm not a four stroke person and cam timing is new to me

One last thing is the cam locating end play pin. The previous "mechanic" thought it ok to reuse these. Haven't a clue how he broke them bu I think i will replace them.



Now I have been running down this alleged " mechanic" that put the new piston in as I work my way out of the mess.
Every thing was going fine and the motor seems to go back together well when it done right.

Now I have to admit to doing some of my own butchering:

I bought this jet kit that along with the jets tells you how to fix a few aspects of the carb. It all sounds fine To me and I'm up for a challenge.


I'm not very experienced with CV type carbs or 4 strokes. The carb is strange with its mechanical cam to force the vacuumed slide open to half way. Then there is the check valve I think it's called it's supposed to richer the mix on back off so that you don't get so much popping from a lean mix.


My instinct is to dump this carb and put on something with a pumper of some type. Only problem is that throttle position sensor. I have never seen a carb with one before. It has to be telling the advance curve where the throttle is open to and it maximises the timing. I can't or can't find out how to replace it yet so I'm stuck with it for now.