1980 YZ100G

[Simo63]

Hi people.

I picked up a little YZ100G at CD10 for my wife to (hopefully) ride after I clean it up and get it going.  It looks shabby but seems pretty original actually.  But I have a few questions for those that know these bikes:

1. Will a YZ125D top end bolt on to the motor?
2. Does this 1980 model share major components with the 1979 and even 1978 models?  Eg ignition?  They sure look the same mechanically?

Makes me laugh you know.  I didn't pay a lot for it but the seller assured me it ran but it was "noisy".  And it was to kick over ... quite noisy in the motor and low on compression.  No worries, a cheap project so expectations are not high

So I get it home and check the basics, fuel and spark.  Cleaned the carby and put fresh fuel in it, kicked it a few times and no go??  Pull to plug to see if it had spark and notice the plug is loose? Check for spark, nothing.  Change the plug for a new one .. still no spark .. remove the kill witch and a few kicks later a little spark?  Hmm. Screw the plug back in tight, kick it over and it's got more compression.  But still no start.  Pull the plug and check, it's wet so no spark. Clean the plug and sure enough, no spark.  hmmm??

Okay so remove the side cover and the screw that hold the stator plate down fall out .. ignition covered in fine metal grindings .... ignition badly scored ..... found the problem I think.  So screw the ignition back into situ and try again but still no spark .. bugger 

I think it's toast.  Will a 125 one fit say from a D, E or F model?

How could the bike have been a runner then??  Like I said, not a lot of $$ changed hand so no complaints but I can't see how it was running before 

On the upside, with the ignition screwed back on there was almost no knocking noise coming from the motor when kicking it over so maybe not as bad motor as I first thought.

Any advice guys and gals?

[cyclegod]

Yes, YZ125 (1W1-2K6) will bolt on as will IT125 (a better choice) side covers etc are the same as IT125 '81(US) ignition from all 77-on YZ100 will fit (not 79' 125 as they have different taper?) they didn't alter much over the years 77-81 except side covers in 1980

[Simo63]

Thanks I was hoping that might be the case 

[rocketfrog]

I have one of those Simo, ignition stator plate and rotor is the same as YZ80F. They go like the clappers.

[curly001]

Simbo you are a glutton for punishment.
Good luck with the new project !
No not the little YZ, getting the leader of the opposition to start riding.

[Simo63]

I have one of those Simo, ignition stator plate and rotor is the same as YZ80F. They go like the clappers.

Thanks .. might have to tame it down a bit then

[Simo63]

Good luck with the new project !
No not the little YZ, getting the leader of the opposition to start riding.

Mate I'm hearing you loud and clear but it was actually her idea a few weeks back ..... soemthing about spending more time together     

[NSR]

Simo, If you end up doing anything with the 100 I might be interested in it.  Damn, I wish I had more time to just walk around at CD and see what was there.

[Simo63]

Simo, If you end up doing anything with the 100 I might be interested in it.  Damn, I wish I had more time to just walk around at CD and see what was there.

Ok mate

[80-85 husky]

this application is exactly why they built xr 200's....

[Simo63]

this application is exactly why they built xr 200's....

Lol. Yes already have one of them but too tall for her at the moment.  Im happy to do whatever it takes to fan that small spark of interest and that is what this is about

[80-85 husky]

got ya, the 100 is the right size...can you drop a dt 175 into that frame? nice easy engine

[rocketfrog]

DT engine will fit but the exhaust needs to be fettled a bit.

There was a YZ100G with a DT donk in it for sale on the Gumtree a while back, looked like a good match.

The 100 engine revs like a banshee and hauls suprisingly well on the pipe. The first time I rode mine was around the backyard and I thought it was so so, probably a little gutless for my young bloke to stay interested for long. Took her out to the track for a squirt and was very surprised when she was on the main jet, talk about fun.

The suspension is total trash and the turning is woeful (even for a 78 KG rider), brakes are adequate - but the engine is real gem.

I often wonder whether a YZ125F shock would be a straight fit, in my opinion the  shock would be the thing that lets it down the most.

I reckon they are a good thing overall and parts are readily available and quite cheap too.

[80-85 husky]

I ve noticed that one of the quickest ways to turn someone of riding bikes is to start them on a powerband!

[Viper666]

Hate typing but if you want to talk ring me. I have experimented with lots of what has been described here. I have a yz100g also.

Perko 0427334186 AH I'm in Vic