[blairsneighbor]

Hey guys, Just bought my first bike. Picked up a Honda Sport 65. Very cool bike, runs well, but it either needs a tune up or there are more serious problems. Came here to get some opinions.

I'll cruise along for a mile or so and all of a sudden i'll loose power, it almost seems like a misfire, i'll adjust the choke and it'll help keep me going. But i'll have to stall out fully, pull over, and then (repeat) Start it up and it'll go for a few miles.

Only had the bike for a few days, definitely needs a carb clean, just haven't had time yet, but that's what I'm going to try next. I checked the plug and it seems fine, but might replace it for good measure.

Thanks for any help you can give.

 

[Dodsfall]

The carb could need a cleaning, or the fuel valve is not allowing enough fuel to pass through. There could also be a partially-clogged vent for the fuel tank.

 

[blairsneighbor]

Sooo I took apart the carb, cleaned it. looking good. But now everytime I start it, it revs alllll the way high rpm. Any idea why. I'm trying to adjust the idle screw but i'm not sure which one it is. Please let me know the screw adjustments and any other reason it may be doing this.

Thanks!
Blair

 

[Dodsfall]

An air leak can cause high RPM. Are you sure the boots are air-tight?

 

[blairsneighbor]

Boots seemed to be tight.

It actually turned out to be the Throttle Slide. It wasn't all the way in place so, when I started it, it was basically as if I was wide open.

all fixed as far as the carb. But now to see if cleaning the carb helped the bog after about 10 minutes.

Update to come. Thanks!

 

[blairsneighbor]

Alright... ****, still not running to great. One question I can't seem to find online and don't wanna take the carb back apart to figure out.

Question:
Is the choke open when It is in the up or down position.

So I took it out for a test drive. Didn't make it very far.. It'll start, seem to be alright, and then it dies pretty quick.

Basically what Ive got it down to is, I'll start it, let it sit and see how long before it stalls. It takes about 20 seconds of nice regular idle and then all of a sudden it revs it's self up and then dies. (ive tried to keep the rev up and it still stalls)

Please help. Really wanna get this bike running properly.

Beers to whoever solves this problem.

 

[Dodsfall]

You usually have to pull up or out for the choke to be on. I'm not sure where it is located on that model.

 

[Rizingson]

There could be a couple of issues you are having, but here's the most logical direction to go
1. You have a restricted fuel flow through the petcock. Remove the fuel line at the carburetor (with petcock closed). Then put the line in a bowl or empty pop can etc. and turn on the petcock for at least 15 seconds each in the open and reserve position. Fuel flow stream should be a full line flow without slowing down. If it slows down or dribbles, remove the gas cap and try again. If it still doesn't flow fully, remove petcock bowl and clean the screen and make sure the orifices and rubber disc are clean. Too check the disc remove the 2 screws by the lever. You can also insert a wire up through both tubes once the bowl is removed IIRC.

When your engine rpm increases by itself just before stalling, it is leaning out due to fuel starvation. Letting it sit for a few minutes allows the restricted flow to "catch up" again temporarily until you run it again.

2. Choke lever down is choke "OFF" or fully open to draw air through the filter.
Choke lever up is choke "ON" or closed intake, allowing engine to draw more fuel for richer mixture at cold start. If your engine idles only in the up position, then you still have a plugged slow speed jet. (very common for people not used to cleaning up carburetors.)

3. Sticky float valve or mis-adjusted float level. Make sure float is not catching on the bowl gasket, and then recheck level as per the manual. Also make sure when you hold the carburetor in front of you with the bowl off, that you can see the float valve freely move up and down when you manipulate the float. It must not stick in the up position.
Hope this helps
I drink Michelob Ultra.

 

[blairsneighbor]

Dudddde!

Thanks Rizingson! I am going to go through the steps. I had a feeling it was the fuel issue. I'll give you an update and hope it all works out.

If and when I am going to need your address to send you that Michelob Ultra!!!

Cheers!

 

[blairsneighbor]

So the Petcock is fine, flows smoothly when in the on position and reserve, with the gas cap closed.

I have this metal peice between the fuel line running from the petcock to the carb. Is this some kind of filter or vacuum? Because I also detached just that line from the carb and turned the fuel (petcock) on and no fuel came out...

I've been trying to look up photos which are not very close on the engine so it's hard to see, but It doesn't seem like there is a piece on other bikes..

Cheers

 

[blairsneighbor]

 

[blairsneighbor]

dunno why that uploaded sideways.. Those other two photos are the metal piece I was talking about.

Thanks

 

[Rizingson]

Looks like a filter someone added. Not a bad idea, but you could either remove it or replace it. I'd suggest you replace it with a new clear fuel line and clear filter so you can see if it plugs up again.
That is your restriction causing the stalling of your engine.
You may also want to clean your fuel system out.
By the way, nice looking S65. I have a black one as well as a red one. My black one is a project I hope to get to soon. My first bike was a black S65 back in 1966 when I wa 15.