Yamaha HS1 90 twin, timing and tuning
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- เผยแพร่เมื่อ 20 พ.ย. 2024
- In this video I install new points and condensers and set the timing using a dial indicator and a light bulb. Then I pull the carbs again and install one new float and two new float bowl gaskets. This has fixed the constant seeping of the float bowls, and the new float replaces the one that was compressed.
That bike sounds great. Sat here with a glass of Tawny Port and 50+ yr old memories of my YL1(UK) 100cc twin☺👍
awesome, I just enjoy the sound, you're right the memories just keep coming back.
these little 90s are so much fun, nothing much like them nowadays.
I have to say the Honda Grom was a big hit with kids and young adults, instead of little 90s those are the kinds of bikes being bought today. And electric! Small electric bikes have taken the place of C90.
I just think all the small bikes are, we use to want to own big bikes, now the small ones are cool.
I guess I'm still lovin the old ones, but I am glad to see young folks still interested and there is something to fill the bill.
It's an angry little monster and I love it. It's running much better with the new points and condensers Dale.
Best wishes, Dean.
Yes sir Dean, angry for sure. Thats what makes it so cool.
Sure sounds great. You make adjusting points look easy. Takes me forever. A lot of work and skill went into getting this little twin to where you have it. Thoroughly enjoyed the ride with you.
It's all coming together now, it has been a lot of work that I really didn't count on, but the icing on the cake is it made some really good content that folks enjoyed.
Running really good now. I guess we'll have to wait till Spring to see and hear this one scoot down the road. I wonder how fast my old 90 twin would go, now that I'm not a skinny kid anymore! Thanks Dale. I needed the flashback today.
I am ready for a scoot down the road too. We will mess with it a bit more this winter, if we get a nice day, a scoot we may do.
Thanks Dale , I Love these old tiny twins !
They are just as awesome now as then. Fun!
Another great video Dale! Looking forward to next spring for the finishing touches.😊
Thanks Steve, the hard parts done, looking forward to some nice new paint.
Points. Lol - blast from the past. Haven't touched a set of those in several decades. Not to far off you'll be needing to cannibalize and make a set. Another great vid. Thx. (btw, that tolerance on the timing is "within a smidge" I believe. You nailed it)
Awesome a smidge is good.
Love it Dale...........thankyou for your style n love that little 90 twin
Nice work Dale. Man that's a sweet little bike!
Cheers, Peter.
Thanks Peter, going to have a great time restoring this one.
Dale yes! You made the point to set the timing in the direction of rotation, i usually have to remind myself and check which way it spins again.
Me too, I usually reach over and pull the Kickstarter to see which way it turns.
Nice one Dale ! 👍
Very meticulously done. It's good that you are able to source the parts even the tiny ones like CB points etc. It is a very long time since everything switched over from CB to CDI. I think once you get Air Cleaners, the motorcycle shall be ready for a spin.
Yes Im happy with it, got a few more parts in. Hope to take a ride before the snow flies.
It's been good to spend some time with you in your shop today Dale. As a young teenager I learned the hard way about cleaning the coating from new points...
Right on Darren, if you leave the film on them, they will burn right away.
@@montana2strokeracer and sometimes, the bike with new points won't run. Clean the points & away it goes. Head scratching until you've seen it before.
Yes sir, the need to clean is paramount.
You must have said a good prayer this morning to get that timing to come out that spot-on on the first go. Great job!
I know Jack, should have gone out and bought a lottery ticket. LOL
Happy Halloween Dale 🎃 On my 750 Honda with dual points , I would set everything up mechanically, set the timing with a strobe and then measure the points with a dwell meter. Made changing the points or cleaning them so much easier the next time, only needing the dwell meter to set the points with the bike running and as I remember from then on the timing would always be spot on also. Enjoy your day!
Yes, you could do the same with these bikes. Most folks don't know or have a dwell meter anymore. Thats how I always adjusted the points on my cars. Just never got in the habit of doing it on bikes, except some of the larger one.
Sounds great
great job as always dale i thought it woz a little rough when it first started but carnt like the cold be better when air filters are on keep up the great work next video please
Thats right Mark, the air cleaners will make it easier to start. They are made to run with them installed .
That engine sounds great!
What a great little bike .
Nice video ❤. Love the sounds.
About the seepage on the carb bowls: one problem I have had before on my old Hondas is the top edge of the float supports interfering ever so slightly with where they sit in the bowls. I would push the bowls onto the carbs with no gasket and the look for witness marks on the float supports. A little dressing with a file allowed the bowls to compress the gasket/oring fully and stop the leak.
Lots of tweaking with this old stuff, you just have to almost reengineer things sometimes.
Great job! I think the engine is lean/cold blooded for two reasons. Main reason is the floats are way too low if you have the float needle with the spring loaded tip. For decades I dangled the float from the hinge pin and leaned the carb body until the slack was removed from the float without compressing the spring loaded needle. The second possibility is the fuel is more too viscous because it is mixed with oil. This usually doesn't bother any circuit except the slow circuit.
Awesome thanks for the tip
Cheers Dale
Very Nice job 👏👏👏👏
good morning, guy`s!
I can't believe you can still get parts for these things. It looks like new on that stator assembly. I wonder if adjusting the timing is the same as the old Rotax twin snowmobiles engines, where with the two sets of points, being mounted on a common backing plate, you adjusted one set of points to the recommended gap. Then you adjusted the backing plate until the light went out when the mark on the stator lined up with the mark on the case. Now with the other set of points, since you couldn't move the backing plate (because it would throw off your first set) you just adjusted the gap on them, until the light just went out when the marks lined up.
Yes, they are all very similar as far as the adjustment goes. These you set each point set to proper gap and then adjust the timing with the backing plate.
My guess on the compressed float is that it was exposed to some really cold weather which caused the air inside to contract creating a vacuum.
If you have a pressure cooker you might try that for getting the air inside the crushed float even hotter if you feel motivated to try and fix it.
I think you may have something there. I am sure they sat out with water in them and froze. Got a new one, works great.
Nice video as always Dale. A couple of comments.
You've got this one tuned now, and it sounds better. However, it just doesn't sound as crisp and healthy as the YL1 100cc twin at all. I think this model was detuned and had a lower compression ratio, milder porting, and maybe more restrictive mufflers. In any case, it just doesn't sound as good as the 100 twin. Don't you agree?
Another issue is that it is running lean due to not having air filters. That's also why it's so "cold blooded."
Dale, you mentioned in this video, and in others, that the point gap opens with wear. This is not true. As the rubbing block wears, the points close up. Sorry to correct you on that, but in the interest of accuracy I felt it necessary.
Nice bike. Nice vid.
Take care,
Robert
Robert, not to spark controversy on the subject, but you are incorrect stating that Dale is incorrect. The points do indeed burn away due to a small amount of spark when opening and closing. The condenser reduces some of the spark but not all, especially when it itself goes bad. I have seen many a set of contact points that were nearly worn away to the metal from excessive wear. Best Regards, Doug. Note: My first bike was a 90 twin. Not a powerhouse, but affordable and fun for a 14-year-old. Sounded crisper with the baffles out.
Well, I have replaced literally hundreds of sets of points, and the point gap closing up due to rubbing block wear has always been a problem; not gap opening up due to burning. Yes, points can burn, but the gap closes due to rubbing block wear.
Sometimes when a points equipped engine won't run, you find that the point gap has closed completely.
A point some don't think about, is that as those points close up, it also retards the timimg.
Vettepilot
Great job brother. Sounds good. What color are you going to paint it?
Probably the same kind of burnt orange.
I buy my float pins by the pound at the hardware store too😮!
Awesome, LOL
In regard to the float I have heard that they could be damaged by compressed air introduced in the fuel inlet with the float bowl in place.
I have heard that too, but I always wonder who in their right mind would blow compressed air in an assembled carb. LOL
Did you use Mrs. Sweger’s kitchen kettle? 😊 I think my wife would draw the line there I’ve often contemplated bringing parts in for boiling lol😂
Well Nick, yes, I did, it is a pot that we don't use much, but so far, she is none the wiser.
@ ha!! I’ve been told to procure my own for the shop!!
Would like to hear this thing WFO going thru a few gears 😃
Like a bumble bee man.
Here
very cold nature, so many moving parts for a small displacement
motor whats the octane rating? You know when bike was new
it was run on
leaded gas witch helps ignition.
Yes, I think once I get the other air cleaner and get them installed it will help with the cold nature starting. Its running lean without the air cleaners installed. I use pump premium without ethanol, 92 octane, I think. Yes, I miss the leaded fuel, gone forever I suspect.
I shall not be defeated by a float. Put that sucker in a vacuum chamber. That carb looks like it got water in the bowl and then froze. That would explain the collapse and corrosion. In my younger years I have used a propane torch to heat the floats but I also unsoldered a few floats doing that. As a last resort you could drill (or unsolder) a hole then use compressed air to destroy, I mean, reinflate the float.😁
Right on, I'm sure I would melt the whole darn thing.
think i had 1 set of points in a dozen that held its gap while tightening screw. just a old school issue that the new kids haven't got a clue about. LOL😀😀😀
Frank no doubt they are a pain in the ass, but folks today will never enjoy adjusting them, Ha!
@@montana2strokeracer see what you mean, guess i like easy also but its like a old radio with vacuum tubes you need to be really old and somewhat odd to enjoy tinkering with these things. i have a old Honda 4 stroker all the crap that needs to be adjusted points,valves, carbs ,timing etc.
yea, the tube still the same color, I would wager your tube to be at least 50 but probably older.
Kept mine in my dwell meter box.