1981 Honda Express SR parts ID/Questions

[agoff]

Hello group. First time poster.

Im working on my 1981 Honda Express SR, i bought for $150 at a yard sale, non running. I removed and cleaned the carb, drained fuel tank, replaced plug, and battery.




It has ran decently for a while. When i bought it it had no air box, so i retrofitted one of those breathers you see on imports, as seen here. the tube labled 3 must have been connected to the airbox, so i stuffed an oiled piece of filter in there to keep dirt out. figuring it was time for a vacuum/fuel line refurb, it came apart pretty quickly..





what of these tubes can i lose to clean things up? im hoping i can lose that piece of filter, maybe install sont T fittings in vacuum lines to do this.

also, what is the name of this piece to the right hand of this photo, with the 3 hoses on the cylinder head? could i lose this too?



seems like the air filter piece and the piece on the cylinder head are related, i would love to remove as much of this as possible while i have the scooter in pieces..

also, i have heard of the honda express/express sr guys removing the oil pump and mixing the gas in the tank. my oil pump is leaking profusely, and causing bogging and smoke during warm up, id love to ditch that too. but do i leave it connnected, just cut, and block the tubes?

I really wish i could use proper terminology, and had more info, but i just dont know small engines well enough.

also, what is high mileage for a 2 stroke scooter? this one had 3500 miles.


Thanks in advance. looking forward to getting this thing going again, and a little bit cleaner also.

[skuttadawg]

I had one when I was 13 and rode it like I stole it with a passenger a good bit of the time and never had any problems . With the open airfilter it is getting more air than with the airbox and you will need to upjet to offset the extra air flow . I used the injector but on a Tomos moped the pump fizzled and I bypassed the low oil float ( disables ignition if the oil is to low to prevent damage ) .Premix is a much safer way to to go .

2Ts are way more sensitive to changes and with the airfilter missing its a good chance it was not upjetting like it should have been . Does it bog any at all ? I would get a new spark plug and do a plug chop to test the jetting . Do you have a compression gauge ? If not Harbor Freight has one for 20 bucks its not as good as an expensive one but better than ball park guessing . You can retry after putting a lil 2T oil in the sparkplug hole and see if compression increases . I can not remember how many miles I got out of mine but it in working order when I sold it and I went everywhere on it . With 3,500 miles it should be good if taken care of but with out an airfilter it was running lean and that can damage the piston and rings like a soft seize .

I would guess those are part of an EGR emission junk . I had some flashbacks of the many great adventures I had on it and an Express . I had around 30 or more mopeds as a teen since I bought and sold them for fun and made a few dollars but mostly broke even . The Hondas were by far better quality than the pedal types .

If you can not get all the help you need here I would visit www.mopedarmy.com and ask . Genuine Honda parts are expensive compared to the generic Chinese parts like many of us use . Its a trade off , brand name with quality but limited aftermarket and pricey oem parts or Chinese will tons of parts for cheap .

Also www.49cc.com has many 2T guys

For 150 I think you did well and know you get enjoyment out of it

[agoff]

Hi, thanks for the reply.

I haven't ran it without an air filter, and im not sure its getting to much air with the one i have, but i know i dont want to mess with rejetting the carb, from what iv seen, parts for these expresses are hard to come by. i know the SRs have alot in common with the regular expresses, but cant find any real info on that.

Yes the scooter bogs after sitting for several hours for the first couple blocks, and pours blue smoke from the exhaust, this is why i was looking at bypassing that pump, and premixing my own fuel.

Is bypassing the pump as simple as cutting, and capping both lines going in/out of it? not to familiar with two strokes, and dont want to deprive it of any oil, or have the pump come apart into pieces inside.

can you explain the "plug chop to test the jetting"? i have my old plug laying around, i imagine i could use that.

I do have a compression tester, what is spec for these things?

thanks for the info, and i will look into those other sites.

[agoff]

Also, what should i expect for top speed for these things? it usually runs about 29MPH, when its feeling like it, it can hit 32 or so, seedometer goes to 40, not that i expect to hit that...