[mattscags]

Hi guys, kinda new here but posted last summer about a 1978 CM185 that I had recently purchased. Now that I am out of winter hibernation I have started working on the bike again with hopes of getting it running. It's getting closer (couple small backfires) but still not turning over.

So far I have replaced the battery, got new spark plugs (and getting spark), set my timing and point gaps, set valve clearance, checked the carburetor (all looks good) and done quite a bit electrical testing. All these seem to be correct based on the research I've done. So I'm wondering if any of you have some suggestions on where the next place to start would be?

The kid I bought if from previously had dropped the cam chain so I got that back on and set my camshaft and best I could. Is this worth rechecking?

Thanks in advance for the help

-Matt

 

[J-T]

Can't hurt to re check the cam timing.

If you have compression and you have spark at the proper time the only thing left is to have a burnable fuel air mixture coming in.

You might check to see if the plugs are wet after trying to start. If so you may be getting too much fuel in which case you have a carb problem.

You can also give it a shot of starting fluid while cranking. If it fires you know it will run when it has a burnable fuel air mixture and that you have a carb problem.

 

[drydreamer]

post some pics of points, cam timing and ign timing

 

[dtsmjr8dan]

Just "setting your camshaft as good as you could" is not good pizza. In order for this bike to run properly, everything needs to be set properly. Do you have a proper manual to set it?

 

[longdistancerider]

The cam may be 180 out of time, you would still have compression and ignition

 

[mattscags]

Thanks for the responses! I do have a manual but it doesn't seem to mention anything about the cam timing exactly. Do any of you have some exact info? I found a picture from a past thread that showed what the cam should look like, can I go off that?

J-T, I have been spraying starter fluid in when trying to turn it over, but no luck. When I pulled the plugs to recheck they were not wet, which leads me to believe the carb is good.

I'll try and post a picture of points, ign timing and cam timing!

Thanks

 

[longdistancerider]

OK, reading thru the manual you have a 360* crank setup which means both pistons are in the same position on different strokes which in this case gives you a single point setup for wasted spark ignition (both plugs fire at the same time).
Camshaft can't be 180* out of time but could be out of time a tooth or 2. Check your compression.
Check your ignition timing
Follow the steps laid out in section 18, page 2 of the FSM

 

[mattscags]

Thanks for the direction with the cam timing. Double checked that and it looks good. Still no luck firing. Here are pictures of the cam timing and points. Just wanted to include these in case you guys had any feedback. Going to run a compression test and see what kind of numbers I get.

 

[66Sprint]

The CAM should NOT be aligned at the F mark alignment, .....It aligns on the T mark....

The points should JUST be breaking open at the F mark alignment, and they're not....So, BOTH are off.....

Feel free to phone.....540-525-5199.....Steve

 

[mattscags]

Sorry those are 2 different timed photos. I just rechecked and the cam picture IS when it is at "T" and as soon as the point are aligned with "F" they start to break open.

I did some tests on the coil earlier and found that I am getting continuity between the wires going in (black/white and blue I believe) but I am NOT getting and continuity between the two HT leads.

Does the coil need to be replaced?

 

[mattscags]

Quick little update. I decided to take the top end completely off and found out that both my exhaust valves and one intake had been bent by the previous ownerNot sure how but possibly tried to start the bike when it was timed incorrectly. So while new valves are being ordered I also purchased a new gasket kit to replace the old ones. Might as well, right!?

Hopefully with all this put back together she will fire up! I also learned to check compression much earlier in the checklist process haha. I'll let you know how it goes.

 

[longdistancerider]

Good to have the answer but kind of sucks there's damage causing it