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Next Mod for the 94A?

Posted: Fri Mar 03, 2017 4:40 am
by hodakamax
If you haven't seen this one, which most of you have, this was a project from a few years ago which was resurrected from junk and eventually was totally restored to a legal Vintage Cross Country racer from the original 94A street machine. The major engine with a mods were reed and 28mmm carb with a Combat head and Circle F pipe. (and other secret stuff, I always say.) I went with the original iron barrel at the time which actually works great. I rode my "Last Great Race" on it two years ago and the machine was perfect. BUT, now I'm looking at maybe putting the final touches on it with this cool Combat Wombat cylinder. I've blasted it and done the preliminary porting but I'm having trouble justifying buying a new piston and fixing something that certainly isn't broke. Not only that, I've not even ridden it since the last great race. What to do. :roll:

Yet another life dilemma.

Maxie

Re: Next Mod for the 94A?

Posted: Fri Mar 03, 2017 6:33 am
by Bullfrog
What to do? What to do? Send it all to me . . . that's what to do. :-)
Ed

Re: Next Mod for the 94A?

Posted: Fri Mar 03, 2017 11:08 am
by taber hodaka
I like options that cost nothing. Send me the size piston you need and I will send you a grabbag that includes Piston, One set of clutch savers and a few other things. It's my TT gig trust and trade. And you make me up a grabbag, tell me not what is in it and then we send them on the same day.------------Clarence

Re: Next Mod for the 94A?

Posted: Sat Mar 04, 2017 3:01 am
by hodakamax
Clarence, I'm afraid you would come out on the short end of the deal. I'm wishing for a new slotted Wiseco piston and I don't think I have enough stuff in the shed to pay for one. I guess I could bore this standard Combat cylinder to .030 like the iron one but that seems like a waste of potential future borings. I'm going to have to sleep on this. :?

Max

Re: Next Mod for the 94A?

Posted: Sat Mar 04, 2017 3:31 am
by taber hodaka
Max I always had good luck with Hodaka ART pistons some times wombat engines sounded rattley to me. I am not up on the new slotted Wiseco piston can you update us. How loose are the Modern hodaka race engines bored to?? Enter my hodaka contest and win GOLD OR SILVER.------------Clarence

Re: Next Mod for the 94A?

Posted: Sat Mar 04, 2017 3:35 am
by taber hodaka
Max send me the cylinder to me as it would be cheaper than sending it to to Ed because Athena is much further away.-- Clarence

Re: Next Mod for the 94A?

Posted: Sat Mar 04, 2017 3:53 am
by hodakamax
Clarence, the 94A was assembled with a slotted Wiseco piston and this is the only experience I've had with them. I did use a Wiseco piston on the Day One Project but did my own holes. The 94As iron barrel engine is a really good combo with its reed and 28mm carb. I don't know what the clearances were on the 94A but all seems well. As for the Day One engine it was too tight at about .0015 and required some additional clearance. I didn't do the boring (never have actually) but it appears the iron cylinders need more clearance than aluminum ones. I guess I'm not versed enough to give an opinion on this but it appears to be the case. Maybe Danny or others are watching and can give us a better opinion.

Max

PS--Gold? Silver?

PS,PS--even AZ (Greg) via E-mail has requested that I ship it to him.

Re: Next Mod for the 94A?

Posted: Sat Mar 04, 2017 4:33 pm
by dcooke007
Max /Clarence,
The new production Wiseco piston box lists the recommended piston to bore clearance just under .002 inch. My experience with aluminum Hodaka cylinders says it should be .0025 to .003 inch. Cast iron cylinders .003 to .0035 inch. Also keep in mind when checking piston to bore clearance extremes in your shops air temp can affect your measurements / results. This past winter I was double checking the piston measurements I had taken on a prior much warmer day. You would be surprised how much some aluminum pistons can shrink when 30 degrees colder. I spoke with one of my better machinist friends and he stated that is why the temp in his shop is maintained year round at about 70 degrees. So if the factory specs the piston to bore clearance at an assumed temperature close to 70 degrees and you are taking your measurements at say 35 degrees....well might not work out to well. Something to think about.

Danny

Re: Next Mod for the 94A?

Posted: Tue Mar 07, 2017 1:37 am
by Bill2001
Jog my memory so I don't need to dig. Upgrading a Wombat 94 to a reed-valved 94A needs cylinder-piston-reed valve msnifold-and 28mm carb on top of the 94-c'case. Seeking to add some low end.

Re: Next Mod for the 94A?

Posted: Tue Mar 07, 2017 4:43 am
by hodakamax
Hey Bill. The The "A" upgrade was mostly just just a change of the exhaust system. All the mods that you mention have been done to my 94A along with a Circle F pipe and Combat Wombat head. You could use your iron cylinder with porting. This all worked out to be a great combo for power, torque and drivability. The pipe is too loud for street and even requires ear protection to race is something to be noted. It's hard to remember how they ran 40 years ago, :? , but I was impressed with the performance of this combo in the last Cross Country race of nearly 40 miles. Wish you were closer, you could try it out!

Max

PS--I really am torn about whether to change to the aluminum cylinder. It all should work and it would really put the final touches on this bike but then again you hate to fix something that's not broken and is actually working really well. :roll:

Re: Next Mod for the 94A?

Posted: Tue Mar 07, 2017 5:26 am
by Bill2001
Good. I'm not ready to mods yet, I want to RIDE!! I've spent most of this first year with the joys of tinkering and puttering, and I'm ready for some seat time.
But on a small-bore dirt bike, low end is always appreciated and I'll do that eventually. I can start collecting bits and pieces now. Since I'm not in a hurry I csn be on the lookout for "deals".
Deals are good and always apprrciated.