Found a piston crack
Thread Starter
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Road Warrior
Joined: Mar 2013
Posts: 1,897
Likes: 1,416
From: Lost
I'm really debating on what to do next. I always wanted to ride this bike as long as possible without assaulting it. I thought I would at least get 150k plus on stock engine. Guess my luck ran out. @702 said I lug it, not sure if that is correct. I'm always between 2000 to 3200 RPM. I try not to be below 2k for sure.
At 70,000 miles not sure if crank is good. Don't mind doing Stage II or big bore from Fuelmoto but I'm afraid with bike this old will it cause further problems.
Other aspect is.....How much is all this going to COST ? Is it worth it or just get a new one.
In the mean time....is it ok if I keep riding on a piston that has a crack in it ? Mostly short rides...less than 100 miles...
Seasoned HDF Member
Joined: May 2018
Posts: 5,814
Likes: 7,142
From: Las Vegas
2k rpm in second gear is fine, 2k in 4th isn't.
If you ride with a known cracked piston, it will break in half at some point. That does not end well.
These guys recommending all this hot rod stuff aren't listening to you. If you're happy with the stock 103 keep it that way. Replacing both cylinders and pistons isn't a big deal, and will last a long time of you're taking care of it. (and not lugging it
)
If you ride with a known cracked piston, it will break in half at some point. That does not end well.
These guys recommending all this hot rod stuff aren't listening to you. If you're happy with the stock 103 keep it that way. Replacing both cylinders and pistons isn't a big deal, and will last a long time of you're taking care of it. (and not lugging it
)
Stellar HDF Member
Joined: Aug 2011
Posts: 2,737
Likes: 1,786
From: Newnan, GA
What???? 
NO! If you continue to operate your bike with a cracked piston, the next thing that you will do is pay for a new engine or perhaps you like the idea of an 850 pound paper wait.
Try to understand the pressures and hostile environment that is inside the cylinder.
At the very minimum, swap out the cylinders and pistons. At that same time a binding test should be done to see if you will need a new fly wheel.
Once the repair is done, Under stand what causes detonation, use better gas with higher octane, down shift to prevent lugging, get a quality dyno tune to improve the gas/air ratio and improve performance and reduce operating temperature..
Detonation
Last edited by Mongo1958; Jul 27, 2024 at 04:33 PM.
Seasoned HDF Member
Joined: Dec 2005
Posts: 19,830
Likes: 7,968
From: poway
Man I would love to but I'm happy with stock 103. Only thing I wish is that it is more responsive. I guess that will happen with Stage I. Is that correct ?
I'm really debating on what to do next. I always wanted to ride this bike as long as possible without assaulting it. I thought I would at least get 150k plus on stock engine. Guess my luck ran out. @702 said I lug it, not sure if that is correct. I'm always between 2000 to 3200 RPM. I try not to be below 2k for sure.
At 70,000 miles not sure if crank is good. Don't mind doing Stage II or big bore from Fuelmoto but I'm afraid with bike this old will it cause further problems.
Other aspect is.....How much is all this going to COST ? Is it worth it or just get a new one.
In the mean time....is it ok if I keep riding on a piston that has a crack in it ? Mostly short rides...less than 100 miles...
I'm really debating on what to do next. I always wanted to ride this bike as long as possible without assaulting it. I thought I would at least get 150k plus on stock engine. Guess my luck ran out. @702 said I lug it, not sure if that is correct. I'm always between 2000 to 3200 RPM. I try not to be below 2k for sure.
At 70,000 miles not sure if crank is good. Don't mind doing Stage II or big bore from Fuelmoto but I'm afraid with bike this old will it cause further problems.
Other aspect is.....How much is all this going to COST ? Is it worth it or just get a new one.
In the mean time....is it ok if I keep riding on a piston that has a crack in it ? Mostly short rides...less than 100 miles...
Thread Starter
|
Road Warrior
Joined: Mar 2013
Posts: 1,897
Likes: 1,416
From: Lost
Fuel moto has a cylinder/piston set up for less than $1000. I may look into that. At 70k don't know how good bottom end is. That's what I'm afraid of. If that is out of spec how much more $$$ am I looking at, hat point better to get a new bike. But won't know until I open it.
Thread Starter
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Road Warrior
Joined: Mar 2013
Posts: 1,897
Likes: 1,416
From: Lost
FWIW I was only referencing the cost between a 107 and 110.. I remember you wanting to stay stock.. Nothing wrong with that.. I did take a 96 2007 egc bored to 103 stage 4 with 80000 miles on it and bore it to 107 and bumped the compression up to 10.5. That was 43000 miles ago.. It still runs like a top... Motor has had over 150 dyno pulls and 4 different cams when it was a 103.
Supporter
Joined: Oct 2022
Posts: 912
Likes: 826
From: Texas
A local machine shop might help you. One here will bore and hone Harley cylinders for $100 each. That's just boring them enough to clean up the cylinder walls. Big bore takes more time and costs more. They sell pistons and will set ring gap for you also.
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Thread Starter
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Road Warrior
Joined: Mar 2013
Posts: 1,897
Likes: 1,416
From: Lost
Ok just talked with fuel Moto, looks like their 107 kit is not a bolt on, I'll have to do Stage II if I want to do that. And given the age of the bike and miles I'm not interested to dump more $$ into this thing.
Given this info now I just plan to replace stock cylinder and piston from Harley.
I was also recommended to change cam chain tensioners ( there are 2 per the guy on the phone). He also recommends cam plate, oil pump and lifers (not necessary but just in case if they are bad).
I was also thinking of fuel injectors, fuel filter and engine mounts while they are there. Do you guys recommend anything else to upgrade while this is done ? TIA.
Given this info now I just plan to replace stock cylinder and piston from Harley.
I was also recommended to change cam chain tensioners ( there are 2 per the guy on the phone). He also recommends cam plate, oil pump and lifers (not necessary but just in case if they are bad).
I was also thinking of fuel injectors, fuel filter and engine mounts while they are there. Do you guys recommend anything else to upgrade while this is done ? TIA.
HDF Community Team
Joined: Jan 2022
Posts: 1,112
Likes: 855
From: B.C.
Ok just talked with fuel Moto, looks like their 107 kit is not a bolt on, I'll have to do Stage II if I want to do that. And given the age of the bike and miles I'm not interested to dump more $$ into this thing.
Given this info now I just plan to replace stock cylinder and piston from Harley.
I was also recommended to change cam chain tensioners ( there are 2 per the guy on the phone). He also recommends cam plate, oil pump and lifers (not necessary but just in case if they are bad).
I was also thinking of fuel injectors, fuel filter and engine mounts while they are there. Do you guys recommend anything else to upgrade while this is done ? TIA.
Given this info now I just plan to replace stock cylinder and piston from Harley.
I was also recommended to change cam chain tensioners ( there are 2 per the guy on the phone). He also recommends cam plate, oil pump and lifers (not necessary but just in case if they are bad).
I was also thinking of fuel injectors, fuel filter and engine mounts while they are there. Do you guys recommend anything else to upgrade while this is done ? TIA.
If you are going that route with nothing to loose, why not buy a gently used piston from someone who upsized, maybe even reuse the rings. Maybe even the cylinder with the piston for a perfect match. Cam chain tensioners should be replaced along with inner cam bearings and lifters. And of course gaskets.
This is the lowest cost way, not the best way.
Last edited by Highway Handler; Aug 8, 2024 at 06:06 PM.