Topic: 350F looses power when climbing hills

[tjpoch]

This last Fall I was on a camping trip with my 73 CB350F and I ran into an issue. It was a 2 day trip & day 1 my bike ran great. The first half of day 2 was the same, bike running really well. After lunch we encountered some pretty big hills & on the climbs I started loosing power.  It felt like my fuel was getting cut off or something.  I needed to downshift and eventually was going 30 or 40mph. If I pulled in the clutch too long the bike would die. It would start back up again and on flat roads would run great, 65-75mph range, normal. But with every uphill it would consistently loose power again.
After the trip I didn’t do any riding since the season was coming to an end, but I wan’t to get this taken care of before Spring.
Any thoughts?
Has anyone else had this problem?

[HondanutRider]

Haven't had this specific problem, but I'd check the gas flow from the tank to the carbs.  It sounds like maybe your fuel level was getting low and/or the petcock standing tube was getting blocked.  Maybe also the petcock strainer is getting dirty (easy to clean).  You would have to remove the tank and then the petcock to properly check and clean the other parts.

[strynboen]

be care driving lean...it burns pistons..          if you loose power better stop and let it cool down..and  let gas run to the  kaburattors..

i vas lucky need just a nev piston...but have i drived it to the end..most of the engine vas lost

[tjpoch]

Haven't had this specific problem, but I'd check the gas flow from the tank to the carbs.  It sounds like maybe your fuel level was getting low and/or the petcock standing tube was getting blocked.  Maybe also the petcock strainer is getting dirty (easy to clean).  You would have to remove the tank and then the petcock to properly check and clean the other parts.

Earlier in the summer I rebuilt the petcock & continued to have the problem right after filling up. The problem was specifically connected to going up hill.

[strynboen]

you use more gas driving up hills...

[tjpoch]

you use more gas driving up hills...

?? So my bike just can't take hills?

[tomkimberly]

Are you using an in-line fuel filter? If so, it's either undersized or plugged. Also check the fule line routing.

Tom

[seanbarney41]

sounds like your fuel level in the bowls is too low

[Don R]

I had a similar problem on my 750, the aftermarket fuel filter, although it looked clear it would not pass fuel. It helped to choke it a little. Yours might be lean, and remember, it's just a 350. Carb jets may have buildup inside.

[krusty]

Have you altered your gearing? Is gas cap vent clear? Compression check?

[tjpoch]

Are you using an in-line fuel filter? If so, it's either undersized or plugged. Also check the fule line routing.
Tom

I am using an inline filter. Ill swap it out for a better one.

[tjpoch]

sounds like your fuel level in the bowls is too low

thats what others have suggested. can you point me in the right direction to adjust this?

[bjbuchanan]

http://forums.sohc4.net/index.php?topic=55789.0

http://forums.sohc4.net/index.php?topic=107927.0

http://forums.sohc4.net/index.php?topic=95865.0

First link is just SOHC, 2nd link is 350f, third is another general

The idea is to angle the carbs so that you don't depress the little plunger on the needle valve. Then you tweak the little tang on the float to achieve the floats just touching your little cardboard cutout tool.

A trick is to file the tang if you see a little dimple on them, preventative measure to stop occasional overflow.

You don't hold the carbs upside down, hold the rack basically horizontal and slip the tool over the top. Use a piece of regular cardboard, old credit card, anything just measure to the height you want to tweak it to