Forde's 1980 Honda H100A

[forde]

Well,

Got this wee honey on sunday. 1980 H100A. Needs some work but overall a nice wee bike! Has oil injection, the fuel tank is cool its a split tank with part of it for the 2T oil instead of a seperate 2T tank somewhere else.

Ive already removed the gross indicators and reflectors, hope to start the real work this week.

 

[Kerzo]

Looks in good nick! What are the plans for it?

 

[lighter7]

Thats a cool looking bike, looks very clean. There are some similarities to my Moto Guzzi.

 

[forde]

Fix all thats wrong with it and get it an mot then maybe new chromeware and a repaint of frame and tank/panels maybe new bars polish a few bits i like its look already so not going mad would like an expansion chamber but none readily available

 

[Tommy]

I travelled around Vietnam on a bike similar to that, i think they call it the Honda win 100cc 1980s

Great little bike for what it was.

 

[chrisQ]

Good luck with her james, good to see someone giving it the attention it deserves. Keep us posted.

 

[mikey]

Awesome! Hard to beat the ring a ding dings and piston rings. Had a rip on one a couple of years back and they go well for what they are! Bit of porting work and a spanny would turn her into a flyer.

 

[forde]

Yeah don't think I'll do any tuning yet have a couple of other two strokes to mess with that way. Don't think there are any chambers for these it seems you have to cut your original down pipe off the silencer and weld on a chamber since it's a brand new genuine honda exhaust that you can't get any more i don't wanna. But they do respond well to be bit of porting apparently. Sounds surprisingly good for a standard exhaust anyway lol

Cheers Chris and Tommy that's class

Lol Mike more like ringringBANG when you mess about too much

 

[forde]

after more reading i have discovered that these pipes actually have a proper expansion chamber inside them, but are made to look as they do. which i did not know.

anyway took me carb apart last nite pilot jet looked like someone had being chewing it, it was mangled and corroded in place.

got it out but its totally wrecked, number on it is well gone, so i dunno what size it is to order my new one. anyone know what size it should be? google is surprisingly unhelpful. not a lot of detailed info for these online.

 

[mx5 turbo]

Are you on bikechatforums.com? Theres a lot of knowledge on there, you could probably find out a good bit about those bikes. Keep the build thread going.

 

[forde]

Will do I have pics of the carb damage to throw up if anyone is interested

A guy on ni bikers has a h100s he is going to check his carb for me the jets are easy to find online its just knowing the right size. Just need to make sure his carb is the same one lol

 

[mx5 turbo]

Stick them up, I just bought another used dellorto carb there as my long choke jet had snapped off somehow and got lodged inside the carb and wouldn't come out. All is good now.

 

[forde]

Well the jet was a 42 so got it ordered last night hopefully here tomoro or Saturday so I can play at the weekend. Need to order a chain and sprockets so I can actually take it for a rip when I get it going. Need an air filter and tyres too and a battery.

The whole top of my pilot jet was broken off man and the part left in was stuck with dirt and corrosion, had to use a easy out and vice grips to get the rest out.

 

[forde]

It was only runnin with the choke or a good bit of throttle I bought it btw which is why I took the carb off. The mangled and blocked pilot jet wasn't givin it any fuel

 

[forde]

Double post

 

[forde]

So first thing to sort is the bike only ran with either the choke or throttle on so there was something up with pilot circuit.

Removed tank and carb, going to clean the tank.

Touched up various worn spots of paint on frame with black hammerite, will probably strip it and get frame blasted this or next winter but wanted to prevent it rusting.

Ordered new pilot jet for the carb as it was blocked and also wrecked.

Carb apparently is a Keihin PF25a. But it says PF18 on it, but apparently this is because it is a 18mm carb in spite of being called the PF25a. But carbs are usually named by size that they actually are. i.e. mikuni VM20 is 20mm, dellorto phbg17 is 17m, etc. So i thought it was called the PF18 but apparently not. I managed to get a early haynes that only covers the A model and it states PF25A as well but does not give pilot size.

Can only find info online for the H100S but apparently it uses the same carb? Anyway H100S manual says a 42, and mike on nibikers has an S and checked and he had a 42.

Hole in new jet noticeably bigger than old one. And threads in different place. But all online resources i read stated that all the carbs used the same pilot jets in different hole sizes but same fitting, and this jet was listed as a keihin PF jet (but not officially made by keihin, made by some other company to fit keihin). The threads appear to be the same pitch so it should screw in so going to give it a go.











Thats all for now!

 

[forde]

Cleaned and rebuilt my carb with the new jet and the wee bike is going perfectly now very pleased

 

[forde]

 

[forde]

Removed forks as thought there was no oil in them cos they were mega bouncy.



Seems i was right, this is all the oil from both legs.



Thinking about adding stanchions to my parts order they are a little rough, probably would still work ok but

 

[forde]

Well lads

sorry for no updates in ages, was going to order my parts i need at the start of the month but my work ****ed my pay over so waiting until my next pay at start of sept now.

in the mean time i just cleaned up the fork bottoms and headlight brackets as it didnt cost anything. they were painted silver and starting to rust through the paint.

bare metalled with wire wheel



one of the fork bottoms was severely pitted. maybe you can see in pic? its the top one. so painted it with my mates special recipe of fibreglass resin and P45 mixture then left to dry.



Then sanded smooth, and all pits were filled.

Primed with plasti-kote metal primer, then sprayed with hycote satin black and hit it with a few coats of hycote clear lacquer.

Looks mint, thought i took a pic of it finished but must not have, will do so later today.

Havent done headlight brackets yet thinking of leaving them bare metal/polished.