Active Active   Unanswered Unanswered

adjusting disc in transmission of Chris-Craft Model B Engine

Keeping your powerboat under power is a lot easier with good advice. Post your power systems questions here.

Moderators: Don Vogt, Al Benton, Don Ayers

Post Reply
jims
Posts: 9
Joined: Mon Aug 10, 2009 6:36 pm

adjusting disc in transmission of Chris-Craft Model B Engine

Post by jims » Thu Jun 22, 2017 8:44 am

My rebuilt 15.5 foot Runabout with Chris-Craft rebuilt Model B Engine runs fine at low speed (350-800 RPM) but will not get on plane when accelerating engine to 2000 RPM.

Looking for detailed instructions to tighten discs in the Transmission. Pictures or sketches of exactly what to do would be very much appreciated.

User avatar
Captain Nemo
Posts: 691
Joined: Tue Jul 07, 2009 7:40 pm
Location: Lyons, NY

Re: adjusting disc in transmission of Chris-Craft Model B En

Post by Captain Nemo » Thu Jun 22, 2017 4:14 pm

Hi, Jim
Does the clutch really seem like it is slipping? Does it over rev when you get to 2 grand? It should take some effort to get into gear. It should also have a distinct pop when getting it into "neutral". If it kind of slides into fwd, the clutch needs to be tightened.
If you take the top off the reverse gear, you will find a locking bolt on the back of the clutch pack. If you remove it and tighten up the the "lid of the can" as I can best describe what contains the clutch discs so that the locking bolt goes into the next or the second of a series of holes. Over tightening is not a good thing as it will cause overheating of the discs.
Boats are to be made of wood, otherwise, God would have grown fiberglass trees.

jfrprops
Posts: 2083
Joined: Thu Dec 29, 2005 10:41 pm
Location: Powhatan Courthouse Virginia

Re: adjusting disc in transmission of Chris-Craft Model B En

Post by jfrprops » Thu Jun 22, 2017 8:22 pm

with how many people aboard? What other weight added if any? That boat ought to plane out at around those rpms...but remember that is no speed demon to start with...great boat though....have fun with that one.

John in Va.
1980 Fairchild Scout 30
19?? custom Argentine Runabout 16'
1954 Whirlwind deluxe dual ckpt 16'
1921 Old Town Charles River 17' (founding Captain, James River Batteau Festival)

User avatar
Ed Andrews
Posts: 54
Joined: Mon Oct 31, 2005 8:42 pm
Location: New Jersey
Contact:

Re: adjusting disc in transmission of Chris-Craft Model B En

Post by Ed Andrews » Fri Jun 23, 2017 6:14 am

I'm no expert by any means but what size and pitch is your propeller? As previously mentioned is the boat loaded or empty? If you're unable to get over 2000 RPMs that would sound like an engine (timing, etc.) or propeller problem.
1951 Chris Craft Holiday
1952 12' Kit Boat w/Johnson 15HP engine

1953 Chris Craft Commander 10HP Outboard

jim g
Posts: 1003
Joined: Wed Dec 14, 2011 10:55 pm

Re: adjusting disc in transmission of Chris-Craft Model B En

Post by jim g » Sat Jun 24, 2017 12:08 am

If the trans is slipping in forward gear it will act just like a worn out clutch in a manual transmission car.

With just you in the boat you should at least get 2500 out of the engine. Has the ignition timing and the high speed jet on the carb been set with the engine running wide open while going done the lake. If not this is where I would start.

Also the B's used 3 different model transmissions. all of them are Paragons and adjust the same why but the locking bolt and what to turn are a little different.

jims
Posts: 9
Joined: Mon Aug 10, 2009 6:36 pm

Re: adjusting disc in transmission of Chris-Craft Model B En

Post by jims » Tue Jun 27, 2017 7:12 pm

Two people in the boat. easily shifts to forward, neutral, and reverse. going to tighten up.

Had to jog engine to get adjustment bolt to top position. Be sure to disconnect distributor wire first; so engine won't start.

Will tighten bye turning finger collar two notches under bolt .

Thanks everybody for your help.

Jim S.

Post Reply

Who is online

Users browsing this forum: No registered users and 8 guests