Hello, new to the forum and already begging for help. I am working on a 305 dream engine model CA77E 318570. I don't know the history of this engine but it was running when I got it. I am having a problem timing the engine as I can't move the points plate far enough to get the points to open at the F mark. They open at about 30 degrees btdc. Engine was leaking oil out between head and cylinder so I opened it up to replace gaskets. I found no O rings on cylinder head studs. I found an extra cam chain master link lying on top of the starter. So someone had been inside this motor in the past. I put new head gaskets and valve cover gaskets in it. Upon reassembly I rotated the rotor to the T mark and rotated the cams so that the alignment mark (dimple) is at the top. But when the cam timing mark is at the top, the (I believe it is called the Red Line of the point shaft cam is pointing down word). My manual says it should be pointing up. Is it possible that the cam shafts have been removed and then put back in incorrectly? There is a missing spline on the camshaft per my manual and I am wondering if it is possible to mate the left and right cams incorrectly. I think that because points shaft cam has two lobes that are 180 degrees apart that it should make no difference if this "Red line of the points shaft cam "is pointing up or down. Am I wrong here? The motor did run before I took it apart to replace the gaskets. So my problem is I can't rotate the points plate far enough to get the points to open at the F mark. I think I am aligning all the timing marks up correctly. Anyone have any suggestions?
Thanks,
Al
Cam Shaft questions
Agarvin,
Welcome to the Forum. I can't help with your timing issue, but you will get your answer quickly. What's your city (I'm in Norcal)? We do have a number of us throughout Arnold-Land ... errr Brownville. Dana
1966/7 CB-77 Red of course 1976 CB-550F (project over-budget and under-funded) 1985 GS-450S (Land Speed Racer) Points camYour description of the parts don't sound right for a CA motor. Some pictures would be helpful.
180 degrees lobes on the points cam? The crank on a 4-stroke motor has to turn over twice to get through all 4 strokes so its 720 degrees instead of 360 degrees that you are working with. Cam turning over one time on a CA is 360 degrees not 180. 180 degrees does sound right for a CL motor, but that would require a different crank. Your engine may have a more interesting history than you think. If you have had it running, there must be a way to do it again. You will probably need to post pictures so some of the experts on this site can see just what you have.
Re: Points camThe CL engine is a 180 crank.
I'll ask him to call me. ....lm
I'm not sure what the proper designation for this engine is, but it has one set of points. The cam lobe has two bumps on it that are 180 degrees apart. The coil is a single coil with two high tension leads for the spark plugs. What I have found is the cam gear (which chain goes around) has a dimple on a tooth just above the flat on the points side. I align the rotor to the T mark. Then rotate the cams with the chain disconnected till the dimple mark is at the top and I can see it per the manual. Then install the chain and master link at this dimple. What I found at this point was that there is a line mark on the points shaft that was pointing down at this point. The manual seems to hint that this line should be pointing up. I have since taken the cam shaft apart and have found that the mark on the points shaft can be installed in one of two positions either with the line pointing down or the line pointing up. This points shaft has a flat on the end which fits into the auto advance mechanism. With two lobes on the point shaft and one set of points, both coils fire at the same time. One cylinder is on compression at this time and the other is on exhaust I think. This is called wasted spark in the Triumph world. I have searched the forum and have found that this seems to be a problem found by others in the past. The original problem was that I could not rotate the points plate far enough to get the motor to static time at the F mark. The points open on this bike at about 30 degrees btdc. Others have just elongated the slots to allow the engine to be timed. I am not sure why this should be necessary unless it is because of wear on either the cam lobe or maybe the points rub bar. I have ordered new points and condenser. Another reason I think someone else has been in this motor is because the original condenser was still mounted on the head, but was disconnected and a type 1 (two lead) condenser was bolted to the engine below the carburetor and wired to the points. After taking the cam shafts apart I can see that they can not be put together incorrectly as the missing splines force them to only go together one way. As my uncle used to say this is a 4 stroke engine, it is not rocket science. I think I am on my way to solving the problem. Thanks to all who responded. Al
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