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1983 aq125b bayliner has no timing mark on the camshaft pulley

S

sinkingnswimming

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"Hello... I have a 1983 bayliner with a volvo (AQ 125B//270)... The timing belt was dryrotted, and came apart when i was trying to start it... When trying to install, i noticed there wasn't a timing mark for the camshaft pulley to line up with (i have the the seloc manual, not much help on this problem)... I removed the valve cover, and tryed to line it up using the #1 cylinder valve positions... It started right up, and ran good at an idle for 2 hours... The next day, it took me 15 minutes to get it running, and ran very sluggish... Prior to the timing belt breaking, it sat up for a winter, and the belt broke while starting for the first time this year... the boat no longer has points, it is now electronic ignition... The boat ran great all last year... I have since replaced the plugs, plug wires, ignition coil, timing belt, dist. cap, and rotor button... Now, i can't even get the boat to run anymore... Has plenty of fuel to the plugs, has fire (not very strong), and has enough compression... My guess is the timing was off a tooth, and now i fouled the plugs... When it ran for the two hours, the exhaust turned the water black... I have done everything i know to do... This is the first boat i have ever worked on, and it is starting to show... If anyone has any knowledge, past experiences, or guesses on this matter, please help!!!! Any and all help will be greatly appreciated!!!! Thanks again, and happy boating!!!"
 
"Chris, if I recall correctly,

"Chris, if I recall correctly, all the Volvo OHC timing gears do have a timing mark (a dot) in the front. Maybe someone installed the gear backwards?

The B21 engines had a couple of locating plates (one at each side of the timing gear) and the one at the back had a notch that was supposed to line-up with the mark on the plate in the front of the head. Not sure about the B230 engines, but somehow I don't think they do have those plates.

In any case, there should be a timing mark (a dot) in the gear (check in the back). Also, if I recall correctly, the timing mark does line-up with the locating pin (or keyway) in the camshaft

http://i24.photobucket.com/albums/c2/Totaled108/P4220220.jpg"

If everything else fails, then try to line-up the locating pin (or keyway) in the camshaft with the timing mark in the plate attached to the head."
 
"Thank you for your fast respo

"Thank you for your fast response... The gear has a mark, however thats it... There is nothing on the head to line it up with... Is the plate on the head you are refering to, something i can buy and install?... I have seen in other post that it should be in the 12:00 position, but there is nothing there... Also in the manual, it shows a motor similar to mine, however the head is strait up and down, and mine is on a slant... Again, thank you for any advice..."
 
"Check on the front of the val

"Check on the front of the valve cover for the mark. If there is no mark, then use the ones in the timing belt. Once you have lined-up the crankshaft and intermediate gears with their respective marks in the block, slide the timing belt with one of its marks aligned with the dot in the intermediate gear; then, line-up the remaining mark in the belt with the dot in the upper gear, slide the belt into the upper gear and you are done.

All the VP 4 cyl engines are installed with a tilt of about 15º towards the exhaust side (starboard), but when you remove them for overhaul, etc and put them on an engine stand you keep them upright when assembling the head."
 
"Ok, the volvo belt was instal

"Ok, the volvo belt was installed new, however the two hours of it running has worn off those marks... Is the mark that is supposed to be on the head, located around the 12:00 position, or does it tilt with the head at the 15 degree angle?... Also, should this mark line up with the center of the valve cover, or should it be a little more towards the 12:00 position?... I will buy another belt if the marks on the volvo belt are my only hope...


Thanks again, and happy boating!!!!"
 
"Below is a link with some pre

"Below is a link with some pretty pictures of B230 timing marks. The photo showing the geometry of aligning the cam timing mark and cam center point with an imaginary line up from the center point of the drive shaft may be of some use in your instance (although that is a B230, I believe geometry is the same on AQ125B):

http://www.threefattigers.com/Protocore/Volvo/TimingMarks.htm

With all the timing marks in the right place as you install the timing belt, the engine should be at TDC (#1 cylinder). At that point, both valves on #1 should be closed, with the #1 exhaust valve next in order to open. If you look at at the cam lobes when you position the timing mark close to where you think TDC is, you can at least get a sense if you are in the right ballpark.

Jonathan"
 
"Thanks for the help here guys

"Thanks for the help here guys... I tried the string geometry line up, and i am right where it is suppost to be according to the photos... Still no luck getting it to crank... It sounds like it really wants to crank, but no luck... It always fires when i stop cranking the engine... With the pics in the book, the string test, and the valve positioning, i am almost sure the timing is where it needs to be... I have taken the new NGK plugs out and cleaned them up, again, no luck... The coil has plenty of fire coming out, but only very little at the plugs... Don't know if this is enough, or if it is even the problem...

Also i am new to this forum, and don't know if i should start a new discussion or continue on with this one, as i am almost sure the timing is right, but not 100%...

Thanks again for your help, and any advice is very much appreciated..."
 
"Chris ,I had the same problem

"Chris ,I had the same problem that you are having .. Was about to give up and replaced the spark plugs and it started right up . just my 2 cents ."
 
"Any chance that the distribut

"Any chance that the distributor may be 180º off and giving spark to a cylinder finishing the exhaust rather than finishing the compression stroke? Remove the sprak plug from #1 cylinder and plug the hole with your thumb; then turn the engine until you feel compression, then keep turning until you no longer feel compression. Now #1 piston should be at TDC (or almost) at the end of the compression stroke. Remove the distributor cap and see to which lead the rotor is pointing at. If it is pointing to #1, that's good; if not, you need to reposition the distributor."
 
"Hmmm..."fires when I stop

"Hmmm..."fires when I stop cranking"...that may be an important clue. Just to rattle off a few checks: follow El's advice to verify ignition alignment/timing; verify firing order/ignition wire installation; try varying spark timing by shifting the distributor in small increments; verify voltage at coil; verify no bad wires or arc points in ignition wires, etc. Also (and this is a stretch) see if you can get it to fire when cranking using a small shot of ether (starting fluid)into the carb throat. Keep your face and flammables away in case of backfire! I have seen similar symptoms with year-old fuel.

Jonathan"
 
"Ok, did away with the NGK plu

"Ok, did away with the NGK plugs, and went with the autolite platnum... Few shots of gas, and she fired up... Still pops in the carb when the rpm is around 2000... I have checked the rotor position at TDC compression stroke, and it points right at #1... Firing order is 1342... The coil was just replaced OEM(5days old)... Also after it running the first time for an hour after the timing belt was replaced, the water in my homeade test tank(40gallons) turn very black... Is that normal, or a sign the timing is off?

Thanks for being patient with me, and thanks for the tips/advice... HAPPY BOATING!!!!"
 
Popping thru the carbs is ofte

Popping thru the carbs is often a sign of a burned intake valve ( if timing is all OK). I did not see in any of our posts that you checked the compression on the engine. Also check the clearance on the lifters to intake valves. If hydraulic maybe sticky lifter(s).
 
"You should verify ignition ti

"You should verify ignition timing with a timing light, I believe the spec is 10 degrees BTDC at 900 rpm (others please confirm). I am not familiar with the electronic ignition retrofit, but I expect that would not mess with dwell on the timing, or timing advance at higher RPM.

Check compression like Robert suggested. This is an OHC engine, so no lifters, just valve shims/cups under the cam directly contacting the valve stems. Typically you would not have to mess with valve adjustment via re-shim unless you were already planning to have the head rebuilt, which may be necessary if you find compression issues due to valve deterioration. If that's the case, have the machine shop set up the head after they do all the machining, including installing valves, shims, and cam. Hope you don't have to go down that road...!

Jonathan"
 
"I have checked the compressio

"I have checked the compression, and all cylinders have 170... Started a new post, assuming the timing is all ok...



Thanks again guys for all the help here... and of course HAPPY BOATING!!!!!!!"
 
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