1987 Evinrude V6 175hp after rebuilt , when release accelerator engine stay high rpm

[ghost2]

I bought the engine death with burnout piston. this is 1987 Evinrude V6 175hp # model E175TXCDR J1143976
So I take out part by part, replace sleeve,cut block for new pistons, new bearings, new seals . Every parts replace for new . After rebuild motor from first start running nice. But when I increase rpm and
release carburettor accelerator , close gas and air . Motor holding high rpm until I kill with ignition key. When I start again with release accelerator running on low rpm.
So I thing maybe I need rebuilt carburettors and after rebuilt I have same problem. Then I replace timer base and two ignition power packs. And same problem. The motor has no more old parts to replace. Guys please help me . Any suggestion I will be appreciate you .This is very strange ,from where motor take air to running on high rpm. Though carburettors are close.
This is video with problem.

 

[ghost2]

[No message]

 

[emdsapmgr]

Interesting that shutting the key off cancels whatever is going on. Once restarted, it runs normal rpm's. I'd make sure that the carb roller is not touching the throttle cam at all when at idle. Your video clearly shows the spark advance lever, but not the carb cam roller action. You should be able to slide a pc of paper between the carb cam roller and the cam when at idle. This makes sure there is no pressure on the roller. Means the carb butterflys should be closed. If one of them is slightly ajar, you can get faster rpm's at idle. I know you've checked, but-recheck the carb butterflys at idle. Hopefully you have reassembled your engine with the correct year ignition parts. The 89 and newer flywheels and timer bases are different part numbers. 89 engines have quickstart and may have different flywheel timer ring markings and timer base markings. If these look-alike newer parts get mixed in an older engine, it might cause timing issues. I'd do another test on the power packs. Disconnect one and start the engine on 3 cyls. See if it will lock onto the high rpm's. Then disconnect the other power pack and test the first one by itself. Would be interesting to know if they both (individually) will let it run high rpm's....

 

[ghost2]

Thank you so much for help I appreciate you , I go to check everything carefully

 

[ghost2]

I check everything still same problem. I think the problem is in ignition advancing. Ignition advancing don't want return to neutral position until restarting engine. I have no idea what stops ignition advancing at high point.

 

[emdsapmgr]

What part number power pack are you running on the engine? Your engine serial number indicates this is a 1986 engine. It basically runs the same electrical system as the an 87. You should be running a pair of 583114 power packs. Your engine does not have the quickstart feature. Have you got a spare power pack to do some testing by swapping it out? I'm looking for the typical recirculation hoses on that engine and don't see them. Is this the correct year block, or an earlier block combined with parts from a 1986/87?

 

[flyingscott]

It looks like the carbs are opening to early. The mark on the throttle cam is usually where you set them to start opening could be hanging up there. One other thing are you sure you put the roller in the right hole on the carb linkage.

 

[ghost2]

Thank you guys for help. Emdsapmgr I installed 2 new power pack 583114 18-5761 and timer base 583129 582394 583377 Trigger OMC 0583377 but before I had same problem on old existing parts.
Flyingscott when accelerator go down then plate butterflies close very tight is no any gap between plate and throttle in tree carbs.
I will do better video on Sunday
Thank you

 

[emdsapmgr]

The engine won't sustain high rpm operation when running on the garden hose without one of two unusual events happening. 1. The timing stays advanced when the timer base is returned timing to the normal idle timing stop. Could be a power pack or timer base linkage issue. To check for this, get your timing light out and check the timing when first started at normal idle. When the engine starts to race, and the throttle is returned to idle, (the timer base returns to idle position) check the actual timing on the marks on the flywheel. Should be the same as your first timing measurement. See if there is a difference in the timing between both measurement points. If there is, that's the issue to fix. 2. The engine continues to get excess air/fuel when the throttle is returned to idle and the butterflys are closed. What fuel pump and hose plumbing system are you using on this engine. A VRO, electric pump, or the old dual bladder pumps?

 

[ghost2]

Thank you Amdsapmgr I check Sunday
My pump is with VRO but I disconnected VRO and I prepare mix myself.
I forgot to say. I cut off my broken temperature sensors which are connected to vacuum switch but I don't think this is cause of problem.
picture pump

 

[ghost2]

No Title

 

[ghost2]

[No message]

 

[ghost2]

maybe does ignition advancing push too far?
I wondering how this system work.
First arm pushes ignition advancing to bumper then second arm start pushes carb butterflys? I can't find any explanation how it works.

 

[emdsapmgr]

What you are seeing is normal spark advance lever operation. The adjustment of the relationship of the carb opening to the timer base movement is detailed in a procedure called "sync and link." The only place it is available is in the original factory service manual. With issues that you are having, you really need to be working from that manual. Check this out: outboardbooks.com Don't settle for any substitute manual.

 

[ghost2]

I will go to check factory manual . Thank you for help .