I know I'm bumping an old thread but hey! Not quite a year later how's that little bike treating you? My girlfriend just bought a 75 F7 175 it's her first bike. . It runs good but we are in the process of getting the lights and such to get it back on the street. A PO removed all these goodies at some point to use it on a farm. I just pursing thread to gleam all the info on this bike that I can.
Last time I tried to take it for a spin back in the fall it didn't want to stay running, I haven't gotten back to it yet while I get my 74 Guzzi back together. I want to pull the motor apart and put in new seals maybe a new piston from what I have read mine is way down on power, given enough road it should do 70 mine struggles to get to 55. A friend suggested I go up on the main do to the alcohol in the gas. 2 strokes don't like it.
I keep hearing that and mine will not even lift the front wheel my old 80 XT250 had no trouble getting a wheel up makes me think my bike needs something.
Sounds like it needs a rebuild, gotta love the old bikes for running even when a rebuilds needed lol. If you like it now, youll love it after the engines back in. Looks like a nice bike though, my brother almost bought one a few weeks ago, had we seen this thread we might have been more inclined to get it. Ended up with a TS185 that was a bit closer to home.
I had one of these back in the day. Bought it with 500 miles on the clock and sold it with 15000. I rode the snot out of it and it was reliable as the sun coming up. In good running order they were very strong 175's and could give 250's fits. I often wondered what ever happned to mine and I love to see people restore them. Mine was a 75 model in green with the black hash stripe. I wish we could still buy bikes like this new. Mine topped out at the time at an indicated 80 running just over the red line. I only weighed 130 lbs back then. I could cruze at 50 and road it back and forth to college which was 75 miles away. It never dawned on me at 18 it was too small for that. My how times change. These were very very good motorcycles for their time.
USe dto ride one of these when I was a kid as well and it was a great bike for the day. My father in-law has one that I ride once in a while now and it has never been rebuilt after all these years and still has great compression and gobs of torque for a 175. But there is no way they ever weighed anywhere near 130lbs. More like 330
I've got a new-to-me 74 F7, and am glad to find an active thread here in the 2 smokers subforum. Actually landed a pair of bikes, a 1975 KE125 in amazing shape (cosmetic *and* mechanical) for my wife, and a 1974 F7 for myself. Hers starts right up, mine is a bit more finicky. If I get it to fire on the first kick, I can ride all over and it'll start right back up when warm; but if I miss it on the first kick, I've gotta let it sit for a few hours. I've got a few bits and bobs on order for it, including a new inlet tube gasket. The old one is being spit out. The previous owner also lost the little rubber plug over the air mixture screw, so It's got duct tape covering the hole. Anyone know where I could get that plug, so I don't have to screw around making one? Couldn't even find it on the parts fiche! Runs great, when it runs, and has a fair bit of power. Bike has ~2000 miles on it; wife's bike has ~3000 miles on it. While doing some maintenance, I think I've figured out that either the choke cable is seized or the choke mechanism in the carb is; her bike has a lot more movement in the choke lever. I suspect thats partially whats preventing mine from starting easily, along with probably a few million air leaks! The inside of the tank on mine has been treated with Kream (Cream?), but it looks like a nice enough job was done. Tank cap was lost and replaced with a car oil filler cap, which leaks a bit. Brake light switch broke and was replaced with a hackish little pushbutton on the lever itself (ebay perch/switch on the way), Tail lens is broke but usable for now, petcock was a bit leaky and PO put an inline shutoff just below it (forgot to thank him for this one.. ) and a few other issues, but so far so good. Doesn't help that its only 40F around here the last few days.
Having had a bit of sun today, though ~40-45F, I got the F7 out and fired up on starting fluid. Seems to idle way high, and not want to come back down. I noted that the air mixture screw on the carb was set at 5.5 turns out, anyone know what the baseline setting should be for that screw? Its usually more like 1.5-2.5 turns, so I'm guessing that mine is leaned way the hell out due to air leaks, and someone tried to 'fix' that with an adjustment. Anyone have some thoughts on where to start tracking down air leaks that would cause high idle on this bike? I'm sure the answer is "replace everything rubber", but .. c'mon, gotta be some biggest offenders
I picked up a 76 125 with 800 miles on it. Rode it about a 1/2 mile changed all the gears. Got it home, ride it 2 miles, it wheezed and died. i can let it sit and warm for 15 minutes with no issues, but riding it always kills it. Well, the clutch was shattered, I guess from the original oil and 35 years of sitting. I also replaced both crank seals and cleaned the carb, which was pretty darn clean. But I still have the same issue with riding it. It goes about 2-3 miles boggs down sneezing, sometimes it backfires. Pulled the plug each time, its not getting fuel. But it won't start again until its cooled. I did note that while the carb cover was off and I was rotating the engine w/o a plug in it that the fuel air was spitting out the side of the carb. And every time I opened the carb cover its coated in fuel oil mixture. It has to be a seal? but I am running out of ideas. I am currently about to change the oring in the rotorary valve, and hope thats the culprit.
OK so I am jumping on here now :) A couple of weeks ago I bought 1972 F7. I know next to nothing about this bike. I have replaced the coil (old one was cracked and done) and cleaned the carb. Shot some ther in carb and it starts so that is a plus. I have a ton more questions about bike. I have gadgets on there and not sure what their functions are. can someone please help???
hey all sorry for jumping on here, but thought all you f7 owners may be of some help. I have a '71 f7 that has been tough to get going, I had it going right after i installed the rebuilt carb, needed to squirt gas in the spark plug hole but got it started relatively easily, but after about 4 min it just died. Haven't been able to get it started since. during that initial start i had a ton of exhaust leaking out where the exhaust meets the engine, so i tightened that up, then realized that the exhaust may actually be plugged so loosened those bolts up and it sounds better like it want's to start again but still won't. I am not sure if i have the carb hooked up right tho as the previous owner must have tried to convert the petcock to manual, as the vacuum line going into the carb case is plugged. So I should then plug the vacuum line on the carb correct? just wondering if someone has a picture of a correct setup of the carb they could send me? also it seems to be flooding the carb really quickly, so not sure if the needle jet or something in the carb is plugged up already. I installed an inline fuel filter but not right away, so i'm sorry to say some crud from the fuel tank may have clogged up my nice new carb. Other than that i am thinking maybe an air leak, compression test is at 120psi with cold engine so adding the 5% to compensate makes it 126psi which i know is a bit low, but when gauge is attached it doesn't seem to drop at all so am i in the clear for a leak in the cylinder? maybe a loose connection on the carb holder? also the rubber cap on the carb is so hard to get on, not sure if mine is on far enough? I'll try to attach a photo. last thing- carb is making a hissing sound when i am at zero throttle and push on the kicker, sounds like air is going out of the carb, what does this mean? thanks so much and sorry for long message.
Well, it sounds like you've got enough compression for it to run. I don't remember the petcock setup, it must be vacuum operated. If the PO tried to convert it to manual it probably wasn't working so yes, I'd plug the vacuum line. The carb flooding means your needle valve is almost certainly dirty or the float is not set at the right height. The exhaust being plugged is a possibility. That happened to mine back in the day. It would start and run but was way down on power, it would top out around 35mph. I took it to a great independent mechanic who was able to cut the exhaust open, burn out the packing/ oil that was plugging it, and braze it back together.
From the looks of that carb I would say it needs a good going through, There is a o ring on the main jet that goes away with age that will cause you problems.
Did a 50 mile ride this Sunday bike ran fine though I blew out my home made exhaust gasket. Other two bikes are a XL175 and a DT250.
