1977 Penton 400 MC-5

[Daniel P. McEntee]

Hello Group; I'm sorta old and new with the POG gang here. I first joined in 2000 or 2001 when I got back into dirt bike with this vintage thing by acquiring a really nice '72 125 Six Days. Since then I've added a Jackpiner ('74 I think), a '97 Jackpiner Edition KTM EXC-200, and just recently acquired a '77 400 MC-5, serial #550 06067. Big thanks goes out to Jeff DeBell for helping me with this endeavor. My younger brother in Atlanta has a '71 Berkshire steel tanker, a '72 Six Days, another 400 project bike and what we think is enough parts to start a 250 build. My oldest brother Tom has a '72 Jackpiner also, so between us we have the whole line pretty much covered. I'll be posting a few questions over the coming weeks about the '77 400 as I go through it, getting ready to do a tear down and re-build. I'm just going through the basics right now,checking things out to see what I need in parts. The bike was pretty complete and in decent shape, with a Missouri State inspection sticker from 1986 on it and a full Petty light kit and rear fender. I'm adding a rear frame loop to make it more like a GS. The first question I have is about the kick stater return spring. The previous owner told me it was broken when I bought it, but I wasn't too concerned. I had an experience with a 175 CanAm where I pulled the wrong bolt that I thought was a drain plug, and let the spring unwind. Found out the trick to that got it back operational without pulling the engine. Had a similar experience with a '77 Hercules and learned the ins-and outs of that model. Is there something similar with the 400 Penton? I have heard about a bolt near the kick starter that could be confused as a drain plug and this holds the kick spring. Can anyone shed any light on this? I haven't found anything in a quick search of the manual that I got with the bike. Thanks in advance for any information that will help. My plan is to go through the bike slowly, add what bits are missing, get it basically safe to ride and see if it will start and run. Then I will do the tear down and do a paint/fix up on the bike. Looking forward to checking in here a little more often.
   Type at you later,
  Dan McEntee
 Florissant, MO

[checkcrew]

Dan,
 hi and welcome,

i know you are a regular on the Vinduro site as are 50% or better here,

look thru the search section here,
 may shed some light on your kick start issue, i am sure Chicago Jerry, Gary Ellis, Kip Kern to name a few will know if there is a quick fix,
Chicago Jerry knows the CanAm engines like the back of his hand as well { maybe the front of his hand too [}:)] ] - LOL -  i'll pay for that one :-))

any-ho keep us posted and ask away,

regards,

Mike Gallagher, NJ.
[email protected]

[checkcrew]

Dan,
 hi and welcome,

i know you are a regular on the Vinduro site as are 50% or better here,

look thru the search section here,
 may shed some light on your kick start issue, i am sure Chicago Jerry, Gary Ellis, Kip Kern to name a few will know if there is a quick fix,
Chicago Jerry knows the CanAm engines like the back of his hand as well { maybe the front of his hand too [}:)] ] - LOL -  i'll pay for that one :-))

any-ho keep us posted and ask away,

regards,

Mike Gallagher, NJ.
[email protected]

[Daniel P. McEntee]

Thanks for the replies. I'm not going to go at this too fast, too much other stuff going on like work and trying to get a bike prepped for the ISDT Reunion Ride. I haven't had the spare time to try a search yet, but we'll see what the weekend brings. I thought I would do this bike differently, and get it complete and running before I stripped it down, thinking it would make the rebuilding process faster. I need to put a notebook with the bike so I can jot down questions as I come across things. Thanks again for the help.
   Dan McEntee

[dirtbike]

There is no quick fix unfortunately.

Here are a serie of pics of my 400 rebuild:
http://tinyurl.com/ktm400mc

[Daniel P. McEntee]

Well I haven't posted much in the way of updates so I will try and do that now. I got the rear frame loop added, and some of the other minor mechanical issues fixed. Got some new cables from Al Buehner at Penton Parts USA and a few other bits and pieces and have the bike running and have been able to make some runs up and down the street. The kick starter spring issue was easily resolved and I'll probably leave the engine alone until I get ready to tear the bike down for cosmetic work. It has very good compression, but it starts pretty easy. Tranny shifts through all six gears smoothly and it clutch action feels good. I think I can declare the bike good enough to take for a bit of a test ride except for rear shocks. The shocks on the bike are some old Curnetts (sp?) that are beyond worn out. I'm going to order a set of Progressives and have decided on which damper to use,(12 Series 12-1203B, 13.5" long) but spring selection has been confusing. The Penton Factory manual calls for a 140 pound straight wound spring for "heavy rider (185 puonds) and MX use." I weigh 260 lbs. in street clothes and was thinking a progressive wound spring in the 90/130 area should be in the ball park for my skill level and posted the question on the VINDURO Group board. Dwight Rudder kind of "shocked" me (pun intended) by posting that I should be looking at the 140/190 or the 140/200 for a '77 Penton 400. That just sounded way too heavy until I started looking at the numbers in the spec listings on Progressive's web site, and talking with my local parts dealer who will be ordering the shocks. After talking about it this morning, we're thinking that Dwight is probably correct. I'm looking at the 140/200 because it is listed at about an inch shorter that the 140/190, and part of Dwight's response was "You get plushness by minimal preload, not by a lighter spring." and with the 140/190 I would be immediately preloading the spring just by installing it on the shock.
  This is the first time I have ever had to order a set of shocks and springs and I would appreciate it if I could get some more feed back on this spring selection. I've know Dwight for as long as I've been involved with the vintage bikes and he's always steered me right, but I would like to understand the whys and hows of why I need this spring. Thanks in advance for any and all input.
   Type at you later,
   Dan McEntee
  Florissant, MO

[wfopete]

Dan,

I can't help you much regarding spring rates but I believe that the '77 models have two positions available for the top shock mount. This will in turn may have a bearing on spring rates and perhalps the length of the shock itself. But FWIW I will share my thoughts on suspension:

The biggest short coming of these older bikes is suspension. The 77 Penton's were on the cutting edge of the suspension revolution so to me it makes sense to use the best/most correct set up shox out there.  Get the best shocks you can afford.  I'm thinking Works Performance or Ohlins. I've always considered Progressive shocks to be mediocre shock and many are not rebuildable. Seems they cater more to the street bike crowd. I don't even think they list Penton's on their web site. Your 400 motor will get you down the trail fast but the suspension can make or break the ride. []

Pete Petrick
175 Jackpiner
Slow but Good

[Rain Man]

Pete, Progressive does list a 13-1/2" shock for the 74 250 Hare scramble. Its 1/2 the price of the WP, and as you mentioned not rebuildable. There great for a light rider and light riding.
 So/Me trail report:  All 1400 miles open till Dec.15th !!!
 Ride on boys

[wfopete]

quote:Originally posted by Rain Man

Pete, Progressive does list a 13-1/2" shock for the 74 250 Hare scramble. Its 1/2 the price of the WP, and as you mentioned not rebuildable. There great for a light rider and light riding.
 So/Me trail report:  All 1400 miles open till Dec.15th !!!
 Ride on boys

Sorry, as usual my mind was in competition mode.  I didn't see 77 model year Penton's listed on the P/S website pull down menu. If Dan is only going to use the bike for EZ riding P/S will probably fill the bill.  But if he wants to compete (especially with a 400 motor), I think he should upgrade.  At 260# dry Dan is probably at the far end of the rate chart. He might want to order a couple of different sets of springs to experiment with regardless of the shock he chooses.

Pete Petrick
175 Jackpiner
Slow but Good

[Daniel P. McEntee]

Hi Pete;
    There is only one shock position on my bike, and that's at the 45 degree lay down position, and the bottom mount is 5" in front of the axle, which from what I understand makes a big difference. I'm a Novice class rider, and I'm, lucky to get out once or twice a year to ride, mostly at the ISDT Reunion Ride. I have twenty something bikes, and this one won't be my main ride, just part of my collection, but you never know how well I'll adapt to the thing and it's power. Price is an issue and consideration. I think if I pick the right spring it will work plenty good enough for me, and no matter what I buy and install, if I sell the bike, it won't be right for whomever the new owner is and they can put what they want on it. Progressive doesn't list any Penton motorcycles on their web site that I could find, and when I emailed their tech department they said they have never fitted a shock to a Penton 400. I based my decision on what they listed for a '76 Rokon, which is similar in size, weight, and travel, and what the Penton Factory manual calls out for. I pulled the current shocks and measured the fully compressed length of the shock mounts and the damper that they call out for the Rokon will work for the 400 within it's travel limits, and for my skill level and level of use, should be more than adequate for the job. The key to the whole thing will be the springs. The factory manual calls for a 140 pound straight wound  spring for a 185 pound rider, and that is my baseline for picking the springs. With my weight exceeding the factory spec by quite a bit clouds the issue. Progressive hasn't answered my last email about my spring choice, so I may have made a pest of myself, although I tried not to do that, and supplied them with the same info I have presented here. I've always been lucky enough in that whatever shocks that have been on  my bikes have when I got them have worked well enough that I have never had to spec out and choose a spring before. I just want to try and get it right on the first try, and I guess it's better to error on the stiff side. There are ways to lighten up a spring if need be. The real problem is my size and weight, and it SHOULD be easier to pick the right spring than for me to lose 75 pounds!  Thanks for the input.  
  Dan McEntee

[tomale]

Hi Dan, I am so glad you brought up this topic. I raced my 76 for several years and I did the best I could with the shocks I had but truly they were the wrong shocks for me. Well that is to say, the springs are..and it made it more difficult to ride. It really played with the steering so getting them right is very important. You maybe right about using progressive shocks in this application, they would not be my choice but then I am not you [8D] I am the same weight as you and so I will be interesting what other may say about what is the right spring rate for this bike for guys like us.

Thom Green,Still crazy after all these years!
76' 250 MC5 (orginal owner)
74'250 hare scrambler (project)
74' 1/2 440 maico
78' 440 maico
72' cr125 Husky (project)
93' RMx 250 suzuki

[wfopete]

That's strange, here is what the two upper shock mounts look like on the '77 GS 250 I'm working on. Or am I using something other than a mount in the picture? I figured the frames on the 250 & 400 would not be different. The more I learn about these bikes the less I know.



Pete Petrick
175 Jackpiner
Slow but Good

[454MRW]

Pete,
Dan has a 77 MC5 400 that he is converting to a GS type Enduro with a rear frame loop, and lighting I assume. The MC5 only has one upper shock mount location. Mike

Michael R. Winter
I enjoy rebuilding and appreciating Pentons!
1974 250 HS Pentons-1980 KTM 175-400'S
1975 Can Am 175 TNT & 77 250 Black Widow
1979 Husqvarna OR390
1976-78 RM & 77-79 PE Suzuki's
1974 CR250M 07 CR125R 79 CR250R

[brian kirby]

Pete,

The MC-5 only has one mount, which I think is located where your shock is in the pic.

Brian

[Daniel P. McEntee]

Originally posted by brian kirby

Pete,

The MC-5 only has one mount, which I think is located where your shock is in the pic.

Brian

  Yeah, mine has only half of that much gusseting, and only one mount. The GS version has six possible shock mount positions and two possible shock lengths (according to the manual I got with my bike.) I added a rear frame loop that I got from a guy on eBay that was a bit short so I had to extend it about 3 inches to fit properly. That made it easier to mount an enduro type fender. The bike came with a Preston Petty headlight/number plate and IT rear fender and a MotoPlat with a lighting coil and full wire harness. It even had some Missouri State inspection stickers on the fork tubes and was licensed as late as 1986. Like Thom says, getting the right spring is more of a safety issue for me than for going all out in competition. I just want to keep the thing under me in the situations that us novice type riders tend to put ourselves in. I have an email into a guy in Indiana that Jeff DeBell told me about and we'll see what he says about spring rates and prices. If he's anywhere near close to a Progressive shock in price I'll probably go with him. Progressive started out OK but has been a little short on follow through on my last email or two. Wish I could figure out how to add a photo and I would put on up of what I have so far. I'll work on that.
  Type at you later,
   Dan McEntee