Help needed to mod a 1980 Johnson V4 85hp

**spybot** · 06-24-2017, 04:24 AM

Guys i have studied the 9 pages for hours now for the life of me i cant find out about Cutting the rod slots?
Can some one give me a heads up on this please

**racer** · 06-24-2017, 06:13 AM

For your application you want to just clean up the area in the flow path,cutting the rod slots does hurt low end. I would also just remove the tit that is left from when they machine the ports. Add 140 exhaust bubble (machine chest as 140) Add 140 cylinder heads, carbs and start 1 size up from the stock 140 jetting on the mains.

**FMP** · 06-24-2017, 06:21 AM

The tit, are you referring to what's left of the cyl sleeve in the two outer ports where the plunge did reach? If yes I've read leave it for the ring support . Post a pic if possible

**spybot** · 06-24-2017, 06:22 AM

Thanks for the input Racer i really appreciate it. So From 85 to 140 V4 Crossflow shall begin as soon as i can have the exhaust plates shipped from the US to the UK. Things i will be doing are Ports only tops ( squared) Pistons Scalloped. Intake machined ??? Add 140 H/C heads. Add 140 Carbs (Dont know about the choke plates? my engine has the primer solenoid ) Might be a new thread. I intend to ad cc reeds is this a good idea ?. will jet as racer suggests.
Anything else should consider ? I have the rev limit cd packs I should changes i think ?
Should i polish grind reed blocks ?

**spybot** · 06-24-2017, 06:35 AM

Originally Posted by racer

Add 140 exhaust bubble (machine chest as 140)

Can you elaborate on this please ?

**spybot** · 06-24-2017, 06:43 AM

Quick off topic question
Has any one got a copy of the service manual for the 1980 V4 crossflow service manual they are willing to sell/copie for me. the ENGINE CODE IS J85TLCSA
Thanks guys for all the input on this thread

**FMP** · 06-24-2017, 09:55 AM

Phillnjack , good looking boat though, looks like Canada with the geese

**racer** · 06-24-2017, 10:09 AM

The ports are double drilled to make each port which leaves a tit in the middle. IMO only remove these and not square the ports, engine will live much better and not have a big power difference. The more you do the more fuel you need to add. It will also need 91 octane or higher fuel and timing set to the heads used.

Ctr bottom of block machined to open block to exhaust bubble better.

**FMP** · 06-24-2017, 10:52 AM

you mean the center bridge?

**71V153** · 06-24-2017, 06:39 PM

Originally Posted by FMP

you mean the center bridge?

He means this: (I think.)

**FMP** · 06-24-2017, 06:50 PM

Tits? Hate not seeing them. Lol

**71V153** · 06-24-2017, 06:54 PM

Originally Posted by spybot

Quick off topic question
Has any one got a copy of the service manual for the 1980 V4 crossflow service manual they are willing to sell/copie for me. the ENGINE CODE IS J85TLCSA
Thanks guys for all the input on this thread

Any factory manual post '78 would be good. I got a '88 manual but to the best of my knowledge no '88 parts. It's all the same.

**71V153** · 06-24-2017, 06:55 PM

Originally Posted by FMP

Tits? Hate not seeing them. Lol

Really! "Grind em off"? How sick is that? ...

**71V153** · 06-24-2017, 07:16 PM

Wish Haynes made a manual for the V4's ...

**FMP** · 06-24-2017, 07:16 PM

Originally Posted by FMP

The tit, are you referring to what's left of the cyl sleeve in the two outer ports where the plunge did reach? If yes I've read leave it for the ring support . Post a pic if possible

Must mean the what's left, outer ports , cyl sleeve