primary pickup...

[briant]

I have read all the posts on the link and sync threads including J.Reeves WOT timing. I have one quick question. Of the two marks on the cam (one marked "start") which one is "the" mark referenced in all the discussions about "the mark should line up with the cam follower roller..." I understand that the importance is more about when it picks up more than where it picks up but I am more than curious. I have not applied Mr. Reeves technique yet to get WOT advance but have done a similiar one for base timing primary pickup. Spark plugs out, timing light on, bring to 3 to 5 degrees, check for initial butterfly movement (primary pickup) but still needed to adjust pickup to be a bit later or she would just bog and die. New carb kits, new fuel lines, new gas, however engine is new to me and I am reviving for my Lund. Compression 130 across the board plus or minus a couple. Going to give Mr. Reeves technique a look see one night this week when I do not have to coach one of the kids teams...but it is raining right now...LOL

Brian

 

[briant]

Re: primary pickup...

sorry forgot... 70 hp evinrude 1984. so how bout it you more experienced folks have some insight for me. Is the bogging a typical problem from having the pickup come in too soon?

 

[wahoo 16]

Re: primary pickup...

read my posts, wahoo 16- 86 70hp johnson vro. i dont know if 84 had intermediate adjustments on the carbs, mid range throttle bog-stall. can you throttle up quickly, and power thru this mid range problem? DO NOT touch wot
timing adjustment, unless you have messed with it, that is the critical one.
severe engine damage possible if wrong setting used

 

[briant]

Re: primary pickup...

Nobody? Hmm. What I am trying to figure out is if having the roller not touch the cam until at the line with "start" on it is a problem, normal, or still seems out of adjustment. I know the common answer is to get a manual, which I did awhile ago, but in the maunual (seloc) it says to tighten the roller as soon as it touches the cam and even with the short line. Mine does not touch the cam until the line marked "start". Is this a typical setup or does it seem to still need something? going to try putting in the water to see how it does tonight hopefully, but really could use some insight here.

Thanks Brian

 

[briant]

Re: primary pickup...

wahoo,

It is more of a holeshot/throttle up problem when the roller is set to the short mark. It just dies when I try to throttle at all from this setting. This is with the timing set at 4 degrees atdc and the butterflys begin to move.

Brian

 

[briant]

Re: primary pickup...

Well tried for some help here but for you folks that may have the same type of problem I tracked down an old johnnyrude mechanic that just filled me up with info. He claims that just one high speed jet is the problem most likely. He also told me about drilling 1/4 inch holes in the prop (most come with these already drilled now he showed me) to help with the bottom end stumble these motors apparently had from birth. He explained about taking the boat to the dock get the motor up right at the stumble point and shooting some premix to each carb to isolate which one is the dog. He said I would know right away. Told me to check all of them because there may be two but most likely just the one. Make sure all the Link and sync settings are right first then perform this testing to find the problem. If the jet looks to be clear, shoot air through the high speed jet hole and check each small hole in the carb throat for air flow. Most likely problem will be the hole(s) behind the butterfly not the one in front if idleing is not a problem. Just thought I would throw that out for anyone who may be following. Might help you also wahoo.

Brian

 

[wahoo 16]

Re: primary pickup...

posted my results might want to read thru them. seems nobody wants to tackle this one. ended up drilling to enlarge intermediate fuel circuit. late production 89 carbs have adjustments for the intermediate, and bolt right on. good luck and thanks for the info.