Topic: bike wont start

[Markcb750]

Doesn't look great. kind of looks like valves to me, except number 4.

Have you adjusted the valves?

The wiggle test is finding the low cam lobe point for each valve, (about TDC on compression stroke) grab the tappet and noting a small amount of play (looseness) in the tappet.

[Loki]

so you dont think its the rings? how do i adjust the valves? i have the book but i like to hear what you guys like to say instead

[Markcb750]

The website has a manual for valve adjustment.  many posts here if you search.  Hondaman suggest a little looser then what manual states; intake/exhaust; 0.002"/0.003 book vs 0.003/0.004 Hondaman.

Could still be damaged valves, but double check that adjustment.  Do you know last time valve adjustment was done, and who did it? 

how many miles?

[Loki]

unfortunately i have no idea when any work was done on the bike.i bought it in -20 weather so i didnt think much of it when it didnt start. i was hoping to have it running for the summer and doing a complete rebuild on the motor in the winter, but looks like i might be doing that part early.

[OldSchool_IsCool]

Wiggle Test:

- remove the tappet covers
- remove spark plugs
- remove points cover
- rest your finger on the #1 intake tappet
- rotate the crank clockwise using the big nut under the points cover
- feel the #1 intake tappet fall then rise again
- after it has risen, look through the round hole at the top of the points plate
- rotate the engine slowly until the T 1.4 lines up with the timing pointer

your crank is now positioned with the #1 cylinder at TDC of the power stroke.

Tappets 1-intake, 1-exhaust, 2-exhaust and 3 intake should have a little wiggle to them.  All other tappets should be firm.

now rotate the crank clockwise 360 degrees until T 1.4 comes all the way back to the pointer.  There should now be wiggle in the #2 intake, #3 exhaust and both tappets for #4.  All others firm.

If you come across any valves that never get firm or never wiggle, then you definitely need to adjust the tappets.

Your manual should have a section on tappet adjustment.  It may be buried.  My Haynes manual has it in the engine reassembly section.  Basically it is the same as the above but instead of just wiggling the tappets, you measure the gap between the tappet and the valve stem.  .002 on the intake and .003 on the exhaust.  Specialized tappet gauges help.

[Loki]

ok what i was thinking of doing was buying a kind of temparary running motor for this season and working on and making run great motor for next season, me and a friend are going to rent out a garage to work on out projects. was just wondering how much a motor would run for a 1977 cb550?....also i have a spare motor for my bike now that i was thinking of rebuilding. what would you guys rebuild instead?....the 77 motor or motor code cb 550e - 1105461....i dont know what year it is. but if you wouldnt mind telling me that would be great.back to the point, what motor would you prefer to rebuild assuming that there both around the same condition. thnks

[Spanner 1]

Temporary motor ? Dude you were one move away from checking the valves, as explained by 'Old School', that could easily be the prob. and a simple fix....keep going.. ya need persistence for these old bikes, but get it right and it will run with very little help for a long time...
Loads of knowledgeable folks available here..run with it !

[Loki]

oh i know and i would love to do the work but i live in a bloody condo and i cant be taking my bike apart in the underground, so thast why im going to rent out a garage to work on the bike. i wanted a temp motor so i just do a complete resto on the motor rather then just fix a lil problem and leave it.

[72COOL]

I like this guys moxie!
Go Canada!

[Loki]

ok great news!!!!!! i brought my bike to my friends shop and the vavles just need to be a lil adjusted all but one of them might be carbon build up on it or something. But its running !!!!! it started and i had it on choke but it dies off choke so im going to remove the carbs and do a full cleaning!!. thanks all the help and ill keep you all updated, i hope to add pics soon when its nice and sunny outside ill take a few of it. cheers

[Spanner 1]

Valve no close fully..... compression no good enough..bike no start!!
Glad you went back to OldSchools suggestion...!

[billybobobrain]

Replace all the gas in the bike! drain the tank, and the carbs, then throw it all awy and start with fresh gas. if your tank has crud in it there is no point in cleaning the carbs, unless you install a fuel filter or clean and coat the tank, or both.