Board index Flathead Power-Technical Questions, Answers, and Suggestions 45 Flatties Stroking the 45

Stroking the 45

Post Fri Jun 21, 2013 12:48 pm
DAK

Posts: 64
Location: Rancho Cucamonga, CA USA
I'm getting ready to rebuild my 45 and am contempating stroking it. I'd like to get some feedback from the guys that have done this. Was it worth it? How noticeable was the performance improvement? Are there more problems or issues as the stroke increases (clearances, necessary mods)? Any feedback would be appreciated. There are a lot of posts mentioning stroking the 45, but not many that actually give info on the performance increases. Thanks.

Post Sat Jun 22, 2013 2:52 am

Posts: 72
Location: South Australia
Best thing you can do to a 45, I have just done mine, 4&7/16 stroke .070 pistons, all done as per booklet you can get, KHK cams advance 1 tooth on the inlet, heaps of low down pull, i ride at 55mph, snap the gas on, I see the front forks rise up as I axcell off down the road, have only done about 300mile on the motor , when it is run in abit more i will see how she really goes, after ridin the stroked motor my stock 45 is boring. but cool. Lota work bit worth it.
cheers Rod
" The more I learn the less I know"

Post Mon Jun 24, 2013 12:48 pm
DAK

Posts: 64
Location: Rancho Cucamonga, CA USA
Thanks, ozihotrod. Did you go with larger intake valves? Stiffer valve springs?

Post Mon Jun 24, 2013 2:30 pm

Posts: 349
Location: Champaign-Urbana, IL
DAK,

I am guessing that you need to order this book as a starting point ...

http://tinyurl.com/n5runrp

It is one of a series of publications written by a former member of this list. For $20, I don't think that you could wrong.

Mark

Post Wed Jun 26, 2013 2:32 pm
DAK

Posts: 64
Location: Rancho Cucamonga, CA USA
Thanks Mark. I have the book. Was just looking for peoples real world experience with stroking.

Post Wed Jun 26, 2013 7:41 pm

Posts: 72
Location: South Australia
DAK, I fitted standard exhaust valve with a larger Inlet valve from KNS, standard valve springs shimmed up as per the booklets, ported and relieved the inlet, 38mm mikuni carb.
" The more I learn the less I know"

Post Thu Jun 27, 2013 12:58 pm
DAK

Posts: 64
Location: Rancho Cucamonga, CA USA
Thanks again, ozihotrod.


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