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Discussion Starter · #1 ·
Hi All,

I'm new to motorcycle restorations and have been rebuilding a 1971 CD175 K4 for the past 6 months. I've ran into a few snags along the way and can't seem to get the engine running right. I've been basing my assembly on a shop manual for the earlier sloper models. Seems that when I crank the engine up I can hear the clutch basket spinning freely and sometimes when I crank it in succession, the crank seems to lose grip or hits a snag in the transmission. I've also tried cranking it while squeezing the clutch lever and the crank seems to disengage. Is this normal? I've followed all the instructions about timing and setting the points gap and valve clearance on the specified timing marks but it still hard to start. When it does start, it revs up really high and then dies when I disengage the choke. it doesn't seem to go into idle. Can you offer any expert opinion or advice on what to check and signs to look for if I've done something wrong with it? Any help would be greatly appreciated.

Thanks.

Dave
 

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Discussion Starter · #3 ·
Hi Dave
When you say crank are you talking electric or kick they're 2 separate systems, with the clutch in you can't start the bike with the kick. If you can't get an idle you'll need to recreant the carbs ( what height is the float set to?) especially the idle circuit and
Thanks for taking the time to reply Simo.

I've figured out the idling problem...turn out it was just a clogged up pilot jet. It's idling now but the engine gets really hot and I can see white smoke coming out of the exhaust. Is this a timing or a fuel-air mixture problem? This is my first build so I'm just trying to figure things out as I go along. Hope you can help out more.

Thanks again!

Dave
 

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Dave, what color is the smoke? How long does it run before it starts to get hot? These engines need airflow to keep them cool, especially in a hot climate. A lean fuel mixture can result in overheating, but I doubt if this is the problem. Make sure the oill is at the correct level and is clean.

If the smoke is blue then it is oil. What is the history of the engine? You say that you have been rebuilding the bike. What did you do to the engine? If the smoke is black it is fuel and it is running rich.
 

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Discussion Starter · #5 ·
Dave, what color is the smoke? How long does it run before it starts to get hot? These engines need airflow to keep them cool, especially in a hot climate. A lean fuel mixture can result in overheating, but I doubt if this is the problem. Make sure the oill is at the correct level and is clean.

If the smoke is blue then it is oil. What is the history of the engine? You say that you have been rebuilding the bike. What did you do to the engine? If the smoke is black it is fuel and it is running rich.
Hi Jim,

Color of the smoke is white and it only takes a few minutes before the engine feels hot. I just filled it up with oil, but I did notice oil leaking from the head cover and it's trickling down and collecting around the left spark plug.

I've had to take this engine apart to get the kick starter spindle resplined and I just ended taking the whole tranny out to clean it all up. I did have to replace the cam shaft as the old one had been refaced rather crudely. Right now it's running with a made up stainless free flow pipe as a muffler. Does the engine running too hot have something to do with the mufflers or perhaps my timing is a bit advanced or just the carb running lean or rich? I set it to 5° btdc. Appreciate any insites you can provide.

Thanks.
Dave
 
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