Hi all. Looking for some guidance here. I've completed the rebuild on my YGS1 and am finding the front fork to be very weak. The service manual said to use #30 oil and a volume of 130cc. I have done that but this seems very weak to me. I'm about 160lbs and can feel the fork bottoming out on rides around the neighborhood. Video below. Any thoughts?


 

130cc sounds a lot fir small firms but I guess with the springs on the outside there's more room. But looks like ya bottoming it out on the oil so maybe!!?. They're pretty softly sprung anyway but ya only getting half movement in my opinion. Sound like metal to metal contact or is it just the brake anchor moving on the forks, axle not super tight. Or rocking forward at the steering head under brakes. That's all for another story though but is it compressing on the oil?. I was assembling those bike & fixing them from new. Cheers from NZ. Ps, mostly YG1T farm models but a few road ones like yours.

Here's a slightly relevant model but strange thing is they show more oil in one side than the other.
But ok after reading that i have to agree with the cc amount you say.
But just listening on my main computer & man it sounds metal to metal contact.
If i didn't know any better i'd place a bet that previous owner has forced a long bolt into the upper or lower guard mount & put a dent into the outer fork.
Sure hope i'm wrong. No spanners missing off the bench. Sorry that's a mean question. Feel free to scald me.
www.legends-yamaha-enduros.com/_files/ug...16bec.pdf?index=true

Thanks all. It'll be back on the bench when I can get some time. It's quite likely that I goofed something up when putting things back together.

Just compress one at a time with guard & wheel off--or forks out maybe--to see if just one side only. Look forward to your discovery.

Thanks RT325...appears to be one leg. I'll pull the fork out and keep digging.

Thanks for the update & look forward to the result.

I think this may explain the issue. It looks like this small pin snapped off inside the fork leg. I'm not exactly sure what purpose this piece serves but I will reassemble without it to see if it solves the travel problem. I may be able to find some lowers on eBay if needed.

Well i'll be blowed, there's a first for everything. It's the damper to trap the oil to stop it bottoming out with a clang. Well, you sure got the "clang" but about halfway down. It'll probably be quite ok for just general riding but only one way to find out i guess. Did it run a differend quantity in each fork or was i thinking of something else i read. Only reason im thinking that is maybe it only has the damper in one side which seems senseless--but!! maybe.
Edit, ok must have one both sides because your parts pic shows the other side showing it & yours fell out of the 'your left side' so must be in both. She'll be good. Maybe run more oil but there's a limit or hydraulics up.
What is the heat around the base? heat on both looking at the video.

Ok...latest update. After removing the broken pin (which is part of the damping system), the stroke on the fork was definitely improved. I reassembled the fork and got it back on the bike. This is when I was reminded of another deficiency with this fork. You'll notice that the wheel when installed in the fork is tilted or biased to one side. I attempted to correct this 20+ years ago with heat and brute force. This is almost certainly what damaged the damping pin. Fortunately, I was able to find replacement lowers on eBay that are in decent shape. I'll be replacing with those to hopefully fix the broken damping pin as well as the tilted wheel. I'll update once I make the switch.