Topic: Overheating issue

[Corbeaux]

Hi Everyone,

Just joined the group.

I purchased a 1978 CB550K last year and have since then left in my local garage/mechanic for modification (I'm not too mechanical minded).

Putting the whole story aside on how they went over budget without telling me and I have to cope it, the day when I am scheduled to pick up my bike, they advised the engine has issue and require to be rebuilt.

They started the bike and I can see smoke coming out from the exhaust, they said if you keep it running, the engine will rattle and the engine will overheat, therefore require a full rebuilt. It is strange as the bike only just had an engine rebuilt 2 years ago, and I am surprised it was gone so quick, especially most of the time, the bike just sat in the shed.

Due to the over-budget scenario, I began to lose trust in the mechanic and wanting to take it elsewhere for a second opinion. I rode the bike away today the first time, 2 intersections in, the bike starting to lose power and stall at the traffic light. I've tried restarting it however have no luck at all. I've waited 10 minutes and restart the bike, it runs, however, you can tell it's struggling, and when you twist the throttle by a little, the engine immediately died again... so I have no choice but to make a u-turn and push the bike back into the same garage.

I took a picture on the engine as it has oil sitting on top.

Seems like a lot of people on the forum says that engine overheating are usually caused by the bike running too lean, I just want to know if someone could share some wisdom with me regarding posible issue, so I don't need to keep spending money on unnecessary repairs...

Many thanks. 

[ekpent]

  Yes the proper amount of fuel is very important in cooling an air cooled engine. You do not mention what mods are done to the engine. Pipe and pods ?  What did you have done at the shop ?  What color is the smoke ?  Did they show you any compression test data numbers or other info on need for a rebuild ?  Do they have a good reputation on old bikes ?  Do you have access to a trailer to get it out of there 

[Corbeaux]

Thank you for the reply ekpent.

Most mods are for converting into a cafe racer look and replacing parts such as dial, cabling, handlebar, headlight etc. Pretty much all the little things that seem a bit worn has been replaced. I believe they did re-build the carb and K&N pods are used. The pipe is a Delkavic 4 into 1 which I supplied myself. The previous seller also advises a 600cc big bore kit was installed.

The smoke is not completely black however highly visible, and they did not provide me with any compression test data or other info, all they told me is "You can see all this smoke? and the vibration coming from the engine? When you run it for a few minutes the engine gets hot and it will shut down, I can't tell you what's wrong with it until I pull it completely apart, it seems like a rebuilt is the only option". 

The reputation of this garage is...how should I put it, Hit and Miss? I've heard good things and I heard bad things, the main reason I chose this garage is that they are walking distance to my home, a price to pay for convenience and I regret not doing more research before proceeding. They do a lot of custom bikes, but mainly Harley and stuff, a few previous built on CX500 and CB400, don't believe they did a CB550 before...

I have been thinking about getting a tow truck just to tow my bike away to a different shop...

[RAFster122s]

Borrow a friend with a truck and ramps or tow truck and get it out of there!!
Any good mechanic is going to diagnose and fix rather than tear it apart and try to figure out what is wrong from examination. They see $$$ and can soak you for $750-1000 or more for their "rebuild".
Find a good shop or pull the motor and send it to Mark Paris, HondaMan, to rebuild it.  Anyone who is diagnosing like they apparently do you need to run away from...quickly.

David

[BenelliSEI]

+1 to above. Go somewhere else. A reputable shop would have checked over the machine before starting any modifications and warned you if there more urgent priorities.

[Airborne 82nd]

Quote (I'm not too mechanical minded) Sorry I'm not trying to be rude but you have the wrong kind of bike unless you want to learn to work on it as a hobby or keep throwing money at it Most shops don't know how to work on these bikes. You could get a good 3 or 4 year old bike to ride and have fun and keep this bike to learn at your own pace. Hope things work out. +1 get it out of that shop they do not give a hoot about anything but your money.

[ekpent]

  Just as a side note black smoke usually indicates an overly rich fuel condition,blueish smoke is oil and white can be condensation in the exhaust pipe. Unless the engine is making horrible noises I would be troubleshooting the carbs and ignition first and not tearing it down to quickly.

[Corbeaux]

Thank you all for your reply.

I took all your suggestions and have organized a tow truck to get the bike out of that shop immediately. I've made a few phone call and spoke with this mechanic 30 minutes away from me, and he has advised the same thing, that the bike may be running too rich instead of lean due to the color of the smoke, he now has my bike and I believe it is in good hand now (finger crossed). He said he has worked on a few CB550 and used to own one, so I guess that is a good start. He did advise that the bike may just need rejetting or they have done a horrible job rebuilding the carb.

As someone that's not too mechanical minded, I understood this is a big challenge going for a bike at that age. I used to ride a CBR500, however, instantly fell in love with the CB550 when I first see it. This will be my only hobby (other than fishing) that my wife allows me to have that I can spend money on, so yes, I am planning to start getting my hand dirty and work the bike inside out, but now, I just want to build a good relationship with a mechanic so that I can run back too if things get serious, just chose the wrong one to start off with   

[BenelliSEI]

Good plan! Good Luck! Now......buy a good shop manual (NOT the Factory one, it assumes you already know what your doing) and find a cheap, nasty “parts bike” (like yours). Tear it apart and start to understand how your machine really works....... welcome to the forum.

[jgger]

To anyone new, the words "mostly work on Harleys" RUN AWAY! Not to bad rap Harley mechanics, but other than 2 wheels and handlebars there are very few similarities.

[Corbeaux]

Thanks for all the comments guys, stop by the other mechanic today and have a chat with him, did a few testing and we come to a conclusion that the carb likely need so work.

One quick question, do you know if carb on a 1975 CB550 can be use on a 1978 CB550?

Mine is a 1978, he has a few spare carb available but they are for the 1975 model, it seems that they look a little different.

[seanbarney41]

Good plan! Good Luck! Now......buy a good shop manual (NOT the Factory one, it assumes you already know what your doing) and find a cheap, nasty “parts bike” (like yours). Tear it apart and start to understand how your machine really works....... welcome to the forum.

the factory shop manual may be hard to understand, but you HAVE to have it to do any real engine work.  There are documented typos in the factory manual, but Clymer, Haynes, et. al, are just wrong in several important sections.

[Airborne 82nd]

Good plan! Good Luck! Now......buy a good shop manual (NOT the Factory one, it assumes you already know what your doing) and find a cheap, nasty “parts bike” (like yours). Tear it apart and start to understand how your machine really works....... welcome to the forum.

the factory shop manual may be hard to understand, but you HAVE to have it to do any real engine work.  There are documented typos in the factory manual, but Clymer, Haynes, et. al, are just wrong in several important sections.

+1 Tell your mechanic about this site if he needs the manual it is here free.