CT70K1 Barely Runs

kcjones33

kcjones33

Member
I rebuilt the engine in 2006 and it ran perfectly with start on first kick for many years. Have not been riding much the last few years and now it will not stay running, just sputters. First item was to adjust points, all was good then I removed the head due to a stripped intake bolt to get a helicoil inserted and suspect it may be too much air due to fitting not being tight and also noticed all the crud around the values. Any comments on what issue I may have? I plan to clean the carb as well. Any feedback is welcome.

Kevin

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6

69ST

Well-Known Member
Going by that single photo, the heavy carbon buildup is a bit of a poser...rich?...extended low-speed operation?...oil?...camera distortion/artifact? Going by the appearance of the valves and plug tip, lack of oil control seems unlikely.

How do the cylinder walls look? They should be uniformly smooth. Did you do a valve job, as part of the rebuild? Leaky valves would hemorrhage compression. Is the intake port clean, or blackened?

It is also more than possible that the carb is gummed-up/varnished...possibly oxidized.

12 years is a long time for an engine & carb to sit, unused. Thus, the storage prep...or lack thereof...could matter greatly.
 
kcjones33

kcjones33

Member
Thanks Racerx. Has really only been sitting ( started only occasionally) for 3 years. Cylinder walls are smooth, but did not do valve job with rebuild. I suspect that is the issue and will get er done. Will clean carb as well. These things take lots to maintain! Will most likely split case again to get the neutral light working to replace that copper ground switch. Trying to get motivated on that one.
 
6

69ST

Well-Known Member
They really don't require very much maintenance or storage prep. But, neglect has its price.

For storage:
  • Drain the oil, clean the oil spinner
  • Drain the entire fuel system dry
  • Rotate the engine to the compression stroke
That's about it, unless you want to grease the petcock packing...to prevent shrinkage/hardening.

Those steps, along with timely oil changes & spinner cleanings will keep the motor & fuel system clean and free of oxidation...indefinitely
 
kcjones33

kcjones33

Member
I was able to clean it all up and looks good now. I replaced and lapped the values and then read afterwards the Clymer manual that says NOT to lap due to special material will be removed and will result in almost instant valve failure. Has any one else had issues after lapping? I used the Dr's $14.99 1005D valves. I still have some work to due before attempting to start and am considering new valves now.

Regards
Kevin
 
kcjones33

kcjones33

Member
Up and running as of today.Starts right up and runs smooth now after soaking carb for a few days, carb rebuild and and new valves. I'll make sure to drain gas and oil before storage in the future.

Thanks all
Kevin
 
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