timing question.

[graybird78]

i have 1990 90 hp force engine. i need to time it. all i see are three marks on flywheel. which mark do i use for timing with engine running . i have a timing light with advance. also have seloc manuel, not much help other than it has timing specs. thanks

 

[jerryjerry05]

You'd have to run the motor at wide open to set it while running 5500rpm's.
​You need to do a "static timing" look at the first few posts and 1 of them had a link to a static timing.

​Static timing is done with the motor off and the plugs out and grounded, in forward gear and the throttle wide open.

 

[SkiDad]

from left to right - 32, 30, 28 you should set your engine to 28 when timing statically. You just have to make sure you throttle is all the way forward like Jerry said - see this link https://www.youtube.com/watch?v=o1HmYyOQFW8

 

[graybird78]

just checked with timing light staticly. its off. trying to figure out how to adjust propoerly. my timing adjustment not like that of the video link. and will adjusting timing throw everything else off. thanks

 

[SkiDad]

watch Frank's carb and timing tutorial - top sticky post in the Force forum. Skip to the part where he shows the black force 125 timing.

 

[jerryjerry05]

Usually the timing doesn't move unless someone has done something to it.

 

[graybird78]

just had to lake today. started better , definately had better throttle response. also got to 4400 rpms. never could get above 4000. and previous owner had no clue how to work on motor. timing was definately retarded carbs were out of sync. he had nothing adjusted properly. it is runnung better each time. still a work in progess.

 

[SkiDad]

What pitch prop are you running ? A lot of times boats have a size too big

 

[graybird78]

i think 15p . i believe is still the oem .the prop looks like been in ww3. bent, chunks out of it, needs new one . going to pick up new or used prop over winter. still has dying issue going in to dock. going to work on it over winter.

 

[jerryjerry05]

A 15p is usually used on pontoons or heavier boats.
​Weight, load and hull shape and the rpm's at wide open dictate what prop you should have.

What do you have the motor on?
Coolers, kids, dogs,too many people and fuel load and trim affect the rpm's

It sounds like the wrong prop??

 

[graybird78]

my boat is a 1990 bayliner capri 1800 br. most of the time it is me and wife. some fishing stuff. and the normal boat things. last time out only quarter tank fuel. has 20 gallon fuel cell.previous p.o used for skiing.

 

[jerryjerry05]

It really sounds like you have the wrong prop or something mechanical is wrong?

You positive it's a 15?
Any #s on the prop?
Look where the nut tightens on the prop?

Do a compression and spark test.
Pull the plugs and see if they are all burning right??

If the PO used it for skiing then he could have used the 15 for pulling or hole shot??

 

[graybird78]

jerry. the only numbers i can find on prop are p669-3.then 669265.these are bye the prop nut.
compression is 125 across all cylinders.
timing was retarded, now is static timed to 28 degrees.
previous owner tried to make it run ,but gave up. thats how i got it.
carbs were not set up properly the link and sync were way off.
has good spark. plugs somewhat oily.
link and sync done to franks video.
plugs are old .need to replace ,one set is champion , one set is auto light.
i know it has exhaust leak, somewhere at front of motor down low under carbs. choking it out. still need to find source and fix.
also need to check recirculation system not sure what that involves.
what po told me was he put new reeds in swapped out carbs and rebuilt them. tried timing motor with out light . one new coil.
let me know what else i can do.
thank you for your time.

 

[jerryjerry05]

Yup it's a 15p.

You sure the tach is working right?
Get a Tiny Tach and compare.

​What speed is the boat getting at WOT?

Any missing when running?
​Any spitting out the front of the carbs when running?

Try running with the cover off?

The recirc system is just removing the cover on the stbd. side of the motor.
You'll need new gaskets as they usually tear and can't be reused.

 

[graybird78]

tach is new. its for force motor.
no missing at all when running.
wot speed is aound 28 mph. not sure if speedo is working correctly. have checked against gps. checks ok ,but last 2 times out has quit working.
not spiiting out carbs that i have seen. have runs without cover idle better and runs better, but got wet.
its a work in progress i like the boat , just going to take time to get it sorted out.

 

[jerryjerry05]

28's way too slow for that boat.

​Get a few inline spark testers .Install them and go for a ride.

See if you drop spark as you accelerate?.
Unhook the tach and see if that makes a difference?

 

[graybird78]

so if i can only do 28 mph and 4400rpm would you think i'm not reaching top end. it does have a hydro foil on it. have not removed it . po said he put it on to help boat get on plane.i'm more interested in optimum performance. with hydro foil on it does reverse worth crap. if i have time i might take to lake make runs without hyrofoil and remove engine cover.

 

[jerryjerry05]

You should be closer to 35-40 maybe more??
The fins actually cut top end down.
​They do help get up on plane.
If they were really an asset??? the factory would build them in to the cavitation plate.

​While running down the river, have someone spray starting fluid around the base of the carb.
Not direct in the carb.
​If it makes any changes in the way the motor runs then the motors sucking air.