please help timing 1988 johnson 150 vro

ssmokey24

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hello i been searching everywhere and cannot find out what my full throttle timing should be on my 88 johnson 150 vro there is no sticker on my airbox can someone please tell me i was told it was 28% bft but want to make sure
 

zildjian29

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Re: please help timing 1988 johnson 150 vro

I would think that you would have to get the timing set at idle first then make sure its advancing
 

ssmokey24

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Re: please help timing 1988 johnson 150 vro

From the reading I been doing idle timing is not that important you want to ajust the idle timing to bring the engine up to 800-900 rpm in gear but the advance is important and want to make sure I have it right
 

emdsapmgr

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Re: please help timing 1988 johnson 150 vro

I don't have an 88 service manual. In the 1986 factory manual, the max timing on a normal 150 was 32 degrees. The 150S model was 30 degrees. In 1990, the factory manual shows max timing on a normal 150 is 32 degrees. It is 28 degrees for a 150S model. You'll need to refer to a factory manual for the specific timing for your year-esp if you have the high performance "S" model. If you have a straight 150, likely it's 32 degrees. Both are +- one degree. Commercial engines are different. You can't set max timing correctly at idle. The timing must be set when the engine is at 5000 rpm's. I would not recommend running the engine at 5000 rpm's on the trailer.
 

ssmokey24

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Re: please help timing 1988 johnson 150 vro

Thanks for the replies my engine tag is j150txcca so I don't think I have the s version my engine was only maxxing out at 4000 rpm so I checked the wot timing and was at 22% so I moved it up to 28% from what I was told but I'm not sure haven't took it out again see if it made a difference now wondering if I should move it to 32%
 

emdsapmgr

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Re: please help timing 1988 johnson 150 vro

Yes, yours is the base engine, based on the model number. Keep in mind the ignition system on this engine will creep (continue to advance) the timing as the rpm's increase. Could be up to 3-4 degrees timing creep from idle to 5000 rpm's. So, make sure when you are setting wot timing, that you account for the creep. That's why the manual says to set it at 5000 rpm's. If you set max timing at idle, you'll be 3-4 degrees high @ 5000 rpm's.
 
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