81 cb750k Trials and Tribulations

[sockmonkey20]

I have a list of things that im sure arent right with my bike.

Choke- the plastic piece that clamps the choke when it is pulled out broke on me when i tried to tighten it,anyone know where/how i can fix it/replace it

Choke-also when i attempt to start my bike when its cold(darn night classes) i obviously use the choke but within seconds of me attempting to warm it up the engine just dies unless i give it gas then it stays alive as long as i give it gas.

Engine/Carb- after a while of riding i get this nasty buildup on top of carb number three(the one behind the little metal pipe thing that is attached to the engine.

Electrical- My wire harness for this bike is completely trashed in places its cut wires and things like links from the battery to the main fuse box is too short like someone cut it and used electrical tape to hold the two links together, does anyone know how/where i can get replacement wire harness for pretty cheap. And i want the oem blinkers gone as well, does anyone know where i can get some Aftermarket blinkers.and mounts

Headlamp: okay the instrument panel mounts dont exactly match up with the headlamp mount when it is seated in the bottom mounting bracket also, I dont know why but on the inside of the headlamp it says 79 650 on it which brings me to the conclusion that the 79 650 had a smaller gap to fill which is why the holes dont line up.anybody on here confirm this.

Controls/Instrument cluster- anyone know where i can get a better set of hand controls for this bike mine are all cracked due to whoever was messing with this bike before obviously didnt know about thread lock and instead cranked down on the bolts that clamp the instrument onto the handlebar

Ignition/Wheel lock- My ignition is easy to switch "to" the park mode but its a Pain in the you know what to put it back to on/off also my wheel lock doesnt work or its just plain to damn hard to turn and i feel like im going to break my key inside the ignition if i try any harder to set the wheel lock. any ideas to fix/replace?
Thanks guys in advance pictures will be coming soon.
David(probably one of the youngest guys to ride this bike 22)

[motogrady]

Welcome to the site guy.

The choke clamp might be hard to find.
Ebay, or make something at home.

The problems with starting and some kind of buildup on #3
tells me carbs need going over.  That's all here, "carb cleaning for dummies" I think.
There's a few vids on utube that will help also.

The wiring harness, I think Vintage cb750.com.
Or just take the time and replace what's bad with stuff you can get
at the local autoparts store.

Aftermarket blinkers and bling, DimeCity.com, or Ebay.

Sounds like someone used a different headlight, Ebay, or I think Tools or Lucky had one for 40 bucks
here in the for sale section, maybe 2 weeks ago.

Controls, DimeCity, Do the Ton.com, or Ebay.
Instrument cluster, I have a set for I think a 1976, speedo and tack included.
That's worth 100 bucks to me.

The keylock, mine was real stiff for a long time.
Door and key lock lube from an auto parts store really helped.
The park position, why even use that?
If that doesn't do it, Ebay.

Good luck, just remember, you are on a vehicle almost 40 years old.
The fact it's still around is kinda amazing, I mean, how many Pinto's do you see out there?
Before you get frustrated, keep that in mind.  Much luck guy

[Johnnylevi]

I have a wiring harness from a cb900. Theyre the same thing you can have it for shipping.
Heres what I got for my 750 http://www.amazon.com/gp/product/B000GU7D0Y/ref=oh_details_o03_s00_i00?ie=UTF8&psc=1

Also I gotcha beat on the age. I'm 21  

[sockmonkey20]

well now my bike has a good ole exhaust leak, lovely, it is really bad in response time with the throttle anyone know of any place that sells the actual exhaust copper for the lack of a better term gasket?

EDIT: i found the copper thingys but i need help does anyone know of a place to get a replacement side engine cover?

[Truck]

Ebay is your friend.  You could build a bik from parts found on Ebay.

[sockmonkey20]

I really hate the stock turn signals, does anyone know of a way i can move them more specifically the front signals, im going to turn the brake light into my rear turn signals(i believe that is possible) anyone have a better way to mount them somewhere else or get another set?

[sockmonkey20]

So more problems with this bike. so i have an exhaust leak coming from the right side i can't figure out which one but there is one there. so i found this guy who can help me out and found some more Gaskets that fit so i put them in(i doubt they are the stock exhaust gaskets but i'm trying to get my bike to start and stay on so im trying everything i can short of replacing them with a new exhaust system.(too pricey right now seeing as how im trying to get another vehicle for the winter so i don't die.(California drivers+Rain=death :(  )) i put them in and i crank down on the nuts for the mounts as much as i could and  still a loud squeal on start up then it goes away as the engine starts to gain speed(rpm) but another problem im having is i cant keep the bike on without holding the start button once i let go of the start button it just dies and a huge POP occurs in i think the right side exhaust pipes. and the engine doesn't want to go past 2000 rpms so im freaking stuck. with no vehicle and relying on my friend and his mom to take me to school everyday:(
the bike was running fine  what could be the problem?
 i did start it up after the battery was replaced and it ran then the next day a huge exhaust leak occurred then i had to drive it(i was in lodi (about an hour away from where i lived and i didn't have enough money for a tow) with a exhaust leak and now it just doesn't want to stay on. i did order the actual Honda stock "gaskets" so when they come in im going to try to fix the exhaust leak but i'm sure that isn't the reason why the engine wont stay on? anyone know how/if i can fix it.(for rather cheap)?? please help me. thanks guys

Also If i can get this freaking engine fixed does anyone have any comstar wheels that they are either selling or want to trade for my spokies(is it possibleto switch them without any major moving around?

[TOOLS1]

Need to step back, and get a fresh perspective on this. An exhaust leak will not have any effect on running, it will just be noisy. It sounds like the engine is only running on 2, or 3 cylinders. Check the temperature of the exhaust pipes to see if any are cold while running. I would also do a compression check. After that we will know which way to go on diagnosing the problem.
TOOLS

[sockmonkey20]

okay because i dont have a compression gauge on hand i did the finger over the hole trick and cylinders 1, and 2 are fine the have decent compression. 3 very low but still has compression number 4 has none i didn't feel anything. if im going to take this bad boy apart what "special" tools will i need to be able to fix. besides a piston ring compressor what else? anyone do a engine rebuild? what tools and things should i expect to have to pay for and how much im looking to pay to fix it.

[TOOLS1]

First you need to take it apart, and see what the problem is, and what you are going to need to fix it.
TOOLS

[sockmonkey20]

Okay well i dont have any way to transport the bike, and my dad complains about me working in his garage so im going to take it to my brother and me and him are going to work on it in his garage. I wont be able to transport it until i get this truck after i get paid so once i take it apart i will take pictures and such to let everyone know what everything looks like.

[sockmonkey20]

Can a leaking head gasket cause complete compression loss in a cylinder?

[TOOLS1]

It would need to be a pretty bad head gasket failure. However you would probably hear the air escaping.
TOOLS

[sockmonkey20]

so tomorrow i will get shop air and run it through the spark plug and seal it off and find out where it is going. should i seal off the other spark plug holes?

[TOOLS1]

Only the one you are putting compressed air into, for the leak down test.
TOOLS

[sockmonkey20]

So does anyone know if the mounting bolt locations on the k model differ from the f model? because i need my bike back in working order and i was wondering if i could just swap them out, the local savage yard has a f model engine so i was wondering if they where the same, the guy at the shop say they are but i just want to make sure they match up before i sink 650 dollars into a engine i cant use.

[TOOLS1]

No difference between the two engines. Just make sure the wreaking yard guarantees the engine to be good, including the charging system. At $650 do they want your engine as a core?
TOOLS

[sockmonkey20]

So im back on the road again but not with the 750 i just bought a kawasaki gpz550 from a friend for 1100 dollars, she has so much more stuff than the honda and its only a couple of years younger its ridiculous the technological difference in the two bikes its a 83, but anywho im back on the grind to figure out how much it will cost to fix the honda engine or just replace it, if i can get the price down below 650 to fix the engine then i wont have to replace the engine:) then i will have two different bikes:) anywho. can sea foam destroy an engine if used in excess amounts?

[sockmonkey20]

So finally got the engine off the bike tomorrow im going to begin taking the engine apart. wish me luck.

[shinyribs]

What did you find wrong with the engine? How did the leak down test turn out?