Vintage Dirt Bike Q & A

Finally got my 73 Elsinore running pretty good after some tunning. I recently completed an overhaul on the stock points and ignition after losing spark. My Elsinore is stock for the most part, stock pipe, modified fmf silencer, stock ignition. Found a couple issues today at the track I'd like some input on. Bike seems to need clutch in most corners to get into the pipe's mid range. I know the bike doesn't pull arms out down low, but the mid range hits hard and pulls clean Into the top end. Carb is clean respone is crisp. Using 110 vp mixed 50/50 with 91. 40-1 yamalube R. NGK B8es gapped at .500mm. Gearing is 13/47. Is this a common issue with these bikes and can adding a few teeth take care of this or is it another possible issue. Second as a result of clutching, I believe I may have used up my clutch as the last session I went to feather it and it was as if the cable had snapped. Then it would come back after I stopped using it for bout half lap. No other complaints as it ran in front of my buddy's worked 75 Bultaco most of the day.

Yep, the meat of the power curve starts right there in the mid range. Stick a new clutch in there, I have no troubles with mine now, though sorry, I forgot what brand I bought. Yes, a tooth or two more on the rear sprocket will help. It is just a matter of getting the gearing to match your speed, so the power is on tap when you roll on the throttle. That way too you don't need so much clutching!
ENjoy,
Jon

Thanks for the reply, I was beginning to think I offended someone. I will do the clutch. Pulled the ,motor last night after finding a crack in the frame under the left foot peg. Drooping peg tipped me off. In the process of rewelding and reinforcing the frame now. Then I found a sloppy countershaft sprocket due to a worn countershaft 23221-357-040. Interested in a replacement part if anybody has one. Still trying to decide on the gearing. Up to a 14 or down to a twelve.

Yep both sides of the frame lowers crack. the footpeg bolt will also give up when you need it most.

As for race prep:
Ditch the srock aluminum tank it WILL eventually break and leak at the top front weld seam. I used a steel 125 tank.
Remove the forks, check out the tubes in V blocks to see if there bent, they usually are and if so they will bind in the stroke when bolted in the triple clamps.
Find a reed valve.
36mm Mikuni
Gunner Gasser throttle.
AXE the on/off kill switch
Find a DG cylinder head.
Add a floding shift lever.
W I D E N those pegs.
TOP rear motor mount tab will break off.
Use some sort of chain tensioner. I lucked out and modded an old up tight one.
MEASURE the width of your cases of the engine while out of the frame, then measure the ID of the frame mounts, add shims accordingly or the tabs WILL break off again.
MUST MUST MUST beef up the pipe mount on the frame. I welded a new tab in the "V" of the frame and used vibe mounts and nyloc nuts. ( shown in pic dscooo44) My first snore build in 1993
Install some lower fork leg protectors to prevent rocks from denting the aluminum.
Port the doog poo outta that cylinder and match it to the cases, dont forget to mod the base gasket to match.
Ditch the points for a PVL ignition.
Ditch the stock motor mount bolts and use new ones with nyloc nuts.
FIX the ball and spring in the kicker so it doesnt keep coming oout and tap you on the calf.
Drill through the frame for the seat bolts and put bolt/nyloc nut in there.
Watch the STUPID aluminum seat pan the brackets WILL fail some day.
Remove the shift fork sliders and polish those puppys so things will slide super nice, also check them for the bendies.
Polish the intake side of the rod.
Keep a good supply of second gear, it WILL eventually shatter.....



In all honesty and this comes from a die hard Honda Man.....even with a totally trick Honda it is still a glass bowl ready to shatter at any time.
Youre gonna be pissed when a sano Hoosk or Penton flys by you.
I swapped my snore for a hoosk and it was night and day better.
Better: frame, engine, reed valve, electronic ignition, up pipe, radial head, air box, nuts/bolts (nyloc)
Same or worse: brakes, clutch, forks. ( you will notice a Honda front end on my hoosk, primo suspension and stop on a dime front brake.
A MAG Hoosk is the way to go

_________________
1994 AHRMA National Champion Sportsman 125 Intermediate.
1996 AHRMA National Champion Classic 125 Expert.

Thanks for the reply and warning. I only plan to race a few times a year, so I hope the glass bowl theory won't come true. I will definitely follow your outline as it seems like sound advice. Maybe I'll be on the hunt for a husky, as I've realized parts seem somewhat scarce and expensive. I'll keep posting as progress continues.

I am glad you mentioned the front sprocket. I originally had put stock gearing on mine, and found it too tall. I tried out a one tooth smaller front sprocket, and found that gearing just right for me so I left it alone. I don't see any unusual wear at all, so I am leaving it alone.

While I haven't shattered any gears, I did wear out the 2nd gear dogs. I will say that is the bike starts popping out of 2nd or third gear, attend to it quickly. Don't wait until it pops out of gear all the time, or you might find yourself shifting into gear on the table top just after the first corner suddenly without any power getting to the ground. Do that at just the wrong time and you might have a big Maico landing on top of you - and it will be your fault. When you have the tranny apart, look up the third gear mod where you cut the face of the gear off and shim the other side to provide more dog engagement. OR, slip a nice fresh 75/76 transmission into the cases to make it easy.

On the tank, keep a layer of stuff between the frame backbone and the bottom of the tank. The tank's weight should ride on this support instead of overstressing the mounts. A tank without some close-cell foam pipe wrap, or rubber blocking, or other support along the length of the backbone will cause it to crack. A properly mounted tank will hold up pretty darned well.

That stock pipe mount is cheesy. I trimmed off an inch from the end of a handlebar, and replaced the stock frame fitting with it in the original stock mounting location. This allowed me to weld all the way around the mount rather than just on the sides like the stock mount. I also doubled up the thickness of the hanger so it wouldn't break in half either. These were simple fixes that retain the stock appearance and have proven way more durable than stock.

I hate to sound cheap (I am ), but I do run the stock points and they work just great. Granted, I don't ride in the rain or mud, so the waterproofing of a cdi system isn't something I need. The bike starts easily and runs great. I don't run a reed valve either. Just a 36mm Mikuni carb with fits right into the stock intake hardware nicely and It is plenty fast for me. I do run what I think is a Pro Form pipe or something like that.

I am just riding the intermediate class, and don't race that often. In this setting, the Honda works great. It happily sits in the garage until it is called to duty, then it springs to life and gladly runs as good as the other 250's in my class without giving me grief. It comfortably runs the outside line with plenty of corner speed, sweeps nicely under power, and holds a high-speed straight line very well. Maybe if I was harder on bikes or a faster or more aggressive rider I wouldn't be happy, but I really do like the Elsinore and have a ball riding it.

I do own a Bultaco 360 Pursang too, and it is right up there in handling with the Huskies. Sure it handles great, but the Honda is a really fun bike too, just different that's all.

Its not the material on the backbone its the rubber grommet and spacers that mount the tank in front, most of the time those spacers have been lost and that allows the tank to be pulled in too far. Just like the upper motor mounts, measure the width of the front tank monts and space the tank out accordingly.

As for the points.....use a dial indicator and an ohm meter to set them @ 1.8~2.0 BTDC. In my travels across the country I couldn't chance the loss of that puny 6volt points system to a DNF.

A BREAKO landing on you over a table top.........hardly....... (true: most riders in the 70's had rider support from two places, breako and Hoosk....guess which one I had support from : P )

One of the fastest riders I saw in AHRMA was Tim Weaver from Hughs Bultaco

Good luck...

_________________
1994 AHRMA National Champion Sportsman 125 Intermediate.
1996 AHRMA National Champion Classic 125 Expert.

Hey ohio I would really like to know your carb specs on the cr250m. The mt250 I built could never run that carb, it was always rich at idle no matter what I did. I know there not the same bike but its way more cr than mt anymore. Its got a dg head cr cylinder with custom reed valve and very aggressive porting with added boost port done by Rich Gagnon. I also burnt up the tranny so I had an mr tranny backcut and I put that in. Right now its got a 32mm kehin flatslide on it and it works well I just couldnt get the mikuni too work. Was also wondering if anyone knows if an aftermarket odyssey cdi would work on the cr250m without any modifications. Sorry not trying to high jack the thread.

My CR is long gone, as I just drag race now, so I couldn't tell you the exact set up I ran but I know it wasn't far from what I got from Carb Parts Warehouse.
As for rich at idle, you know the air screw drill don't you? In = rich, out = lean so if your highest smoothest idle was at more than 2.0 turns out that is telling you your polit is too rich.
I never had any issues like that with mine aside from setting the air screw for the conditions of the day.
As for the ody ignition on the CR I did hear that would work, just like the DG head does.

I ran a PVL Ignition on everything. The Late Daine Leimbach was part of the Penton ISDT team whom I met many years ago when the Penton Team raced at Amherst Meadowlarks hare scrambles, Daine worked for Penton Imports in the Motoplat/PVL ignition lab. He used allot of my bikes to make the stator plate/rotor for the PVL ignitions so I got them for a song.

_________________
1994 AHRMA National Champion Sportsman 125 Intermediate.
1996 AHRMA National Champion Classic 125 Expert.

Yes ohio I know that carb inside and out I have so much brass for it, its a little absurd. I guess I will give it another go this summer and try to get it right. I wanted the pvl but I dont have the money for it and I know of a cheapish mototek unit for an fl that I am now going to get. I had a sunburst dg head as well and yes they will fit too but I sold it and kept the sand cast one instead as they look nicer. You have to remove a stud or two from the cylinder to use the sunburst head but it will fit. Thanks for the help its much appreciated.

Well after doing some welding, shimming, tightening and prepping I got the 73 elsinore out today. Spent a lot,of time on the points, timing and carb. Moved clip up one slot. Seems to have paid off. Found some bottom end that had been missing from the motor. Mid now hits hard. Was capable of pulling the front wheel at will today with just a good twist of the throttle. Went back to stock gearing. And the clutch seemed to have regrouped. think ill try a couple of barnet springs. Ran a Spectro two stroke oil today specifically made for air cooled smokers. Mixed at 40-1 into sonoco 110/91 50:50 mix. Seemed to,run richer than the yamalube mixed the same. Overall really fun day. Next on the list, fix the leaking forks. Second set of seals and still leaking. Starting to think maybe the lower legs could be worn, doubt the chrome is thin. No pitting or rust. Any advise on good seals or techniques.

Like I said before, take those forks apart, put the sliders in "V" blocks and check them for the bendies.
Any good hydraulic seal supplier will have them, just take the seal with you so they can get the numbers off them. Fresh new seals are the ticket, not some NOS Honda ones that have been sitting on a shelf hardning for 30 years.
You will prolly need to reaplace the bushing on the sliders, should be some avail on the bay. That will help a bit in action. Also try to find some new wipers, old ones only let in dirt which will toast your new seals in minutes. FORK BOOTS !!!!
Make sure any pits are out of the sliders, I used to use fine fine fine emery cloth to get any out. I also ran fork boots at the more rockier/mud races. I also had goki air fork caps on all my forks, NOT to add air but to bleed it out after every ride.
After every practice/moto I always popped the dust caps up used a toothbrush to get any dirt out and give the seals a ever so slight spray with WD40.

As for the timing, I messed allot with it and using a dial indicator and Ohm meter to see when they open is key. 1.8~2.0 btdc gave me the best overall ease of starting and power.
If you hear other Elsies popping on decell you know their timing is fritzed, also they will kick back when they try to start them up.

I know the national sales rep at spectro and have been using their oil for a long time with zero issues, even at the toughest track on an air cooled engine (MX338 @ Southwick Mass) zero issues.

Glad to see everything is working on your sanitization of the snore.

_________________
1994 AHRMA National Champion Sportsman 125 Intermediate.
1996 AHRMA National Champion Classic 125 Expert.

When ever you install new seals make sure you grease them up really well otherwise your going to ruin them.

I wouldn't put grease in there........

You do put anti stiction lube in modern upside down forks, fork seals.

_________________
1994 AHRMA National Champion Sportsman 125 Intermediate.
1996 AHRMA National Champion Classic 125 Expert.

Well I got a new set off fork seals and dust covers from a company called allballsracing. They look to be far superior in quality to anything I've tried in the forks before. The rubber is soft and claims to have a double lipped technology. I rolled my fork legs on a machinist table and noticed a radius in both legs. Any advise on replacement legs as I suspect most second hand legs will be bent the same way. I also tapped and used a set of air tank valves in both caps as a way to release built up air after motos. Either way blowing seals or not, the forks are going back together for now until I find some suitable legs.

What tires sizes are most racers here running. My rear is Dunlop D756 100/100-18, front is bridgestone M403 80/100-21. Rear seems fat or wide for a 250. I know on my CRF 450 wide back tire equals lazy and not very sharp handling. I looked at the manual, but all it shows is 4.00 x18 and I think 3.00 x 21. As usual thanks for help.