All over the place...Maxim/Seca build

Jeff0133 · Sep 19, 2016

So paint it Will be...i'll cure it in an oven I got for 50$...I Will pre-cook the parts for off-gasing just to make the painting easier and more durable.
But for now I am cleaning...god damn I hate this...especially the baked on gaskets like on this part...

I was able to take it off using a box-cutter blade and a lot of solvent and then steel wool...took an hour or so...
On a brighter note, I rigged up a DIY media blasting cabinet using a plastic bin, some Lexan...etc.

Works pretty good, Sand blasted a couple covers...

The sandblasting gave the aluminium a rough finish which will be good for the paint to come...
...still a lot more cleaning to do...

Jeff0133 · Sep 21, 2016

I think I might replace the starter bearing in the crankcase. Anyone know where I could get those?

rshutchinson · Sep 21, 2016

Powder the cases. You won't have a problem getting powder in to any areas there and it's so much more resilient and chip resistant than paint.

rshutchinson · Sep 21, 2016

Also, aircraft stripper on the gaskets works well. Spray it on and leave it for a while, then use a scraping blade to get them off.

Jeff0133 · Sep 22, 2016

Still washing, sandblasting,cursing...this shit takes TIME, for now I have to pull the brakes as I am looking for conrod bolt replacements and maybe, since it seem I will be blowing thee lines on any sort of budget I might set :twocents:

...be looking to replace crankcase bearings and conrod bearings as well...idk :umm:

I've posted this in other threads but anyone find a place to order bearings from that won't rip both my arms out...price/shipping wise?

Jeff0133 · Sep 22, 2016

Or maybe i'm overthinking/overdoing this...kinda OCD....

Jeff0133 · Sep 26, 2016

Still cleaning...this time pistons and valves, soaked in carb cleaner then gave them a good rub

Some valves seem a little pitted, but still seat pretty well and i've got the grinding compound and tools on hand to reseat them.

Jeff0133 · Sep 26, 2016

Waiting on a few emails for conrod bolts
ARP has a set that should fit, these guys are awesome when you contact them.

Will update when I get more info on those...

Jeff0133 · Oct 16, 2016

Conrod bolt issue resolved , boats.net had some in stock...ordered,got them in the mail, got my new starter clutch bearing also, just need to figure out how to take it out without buying a blind hole puller (100$ tool for a 10$ bearing).Also ordered the little oil gauge window thingy that I couldn't see through anymore, will be getting that this week.
Also cleaned and sandblasted all the engine parts, just need to give them a good once over with acetone,preheat in my 50$ garage oven and get on with the masking and painting...
This takes a huge amount of time and elbow grease but preparation makes or breaks a paint job so I spent the last few weeks on that.
Will post progress/pictures by the end of this week

MerlinDudley · Oct 16, 2016

Hi Jeff, did I read somewhere in one of your posts, that you were thinking of putting a six speed transmission, in yout Maxim engine? As I'm interested in trying to do the same thing! 1, Would all the extra bits fit inside the crankcase?
2, Would it need any machining, to get the transmissins swapped over?
3,Would the selector drum need any modifications?
Thanks in advance, for any relevant information, on swapping the transmissions over.

Merlin

Jeff0133 · Oct 16, 2016

I have a Maxim, I bought a Seca as a donor for 100$...Took the engine apart thinking I would put the tranny in my Maxim.
But, the Seca engine was in great shape so I decided to rebuild/paint it and simply swap the engine...then use the top end of the Maxim engine to eventually go Big bore on it...but not now.
To answer your question, yes I am going the 6 speed route but with an engine swap.
It is the same engine , the only difference being the transmission. I think if you want to go the 6 speed route also the simplest way to do that is to swap the engine for a Seca engine...also you can get a donor for less than you would pay for the tranny alone imo.

Jeff0133 · Oct 16, 2016

Remember that bearing problem....Well it ain't a problem more..
I had some steel lying around my garage so I made a "T" handle that I welded to the bearing.
Gave a couple of sharp rasps to the underside of the handle and VOILA!!...out came the bearing.
Saving money that way is really gratifying

MerlinDudley · Oct 16, 2016

Thanks for your reply Jeff, but, it will be cheaper, for me to swap over transmission, as a guy I know wants my 5 speed gearbox, in a straight swap for his 6 speed box! I have no idea why he would want to do this, but I'm not complaining!
So, you think that the 6 speed will just slot in, in place of my 5 speed, without any modification?
Thanks so much for that Info, Jeff!

Merlin

Jeff0133 · Oct 16, 2016

I have the Maxim engine in my garage, I'll check tomorrow.
My eyeball assessment is that it would fit.
Just make sure to swap everything,tranny, shift drum,shift forks....etc
Will check tomorrow and get back to you.

MerlinDudley · Oct 17, 2016

Thanks so much Jeff, that will be great! As when I'm out riding the Maxim, I am always thinking that it seems to need that "extra gear"

Merlin

Jeff0133 · Oct 17, 2016

Yep, thought the same thing, I might also play with the sprocket sizes...

16VGTIDave · Oct 17, 2016

As I understand, the Seca ends up having the same overall gear ratio in 6th as the Maxim has in 5th. Assuming one is using stock sprockets. It just takes 1 more shift to get there. If you start changing sprockets, things get interesting. I will caution you to NOT reduce the engine RPM's unless you weigh less than 100lbs on the bike. The DOHC engine does not like to be lugged. It will return better performance AND economy if the revs are kept up. Or plan on downshifting when you want to accelerate, or go up a hill.

All that said, I must be honest and admit that I'm picking up a Seca motor tonight. I hope to freshen it up a bit and swap it into my bike, if it is worthy. Otherwise it will be used for spare parts.

Jeff0133 · Oct 17, 2016

My build will be a Cafe-ish city bike. As such, I wish to make it light and peppy so the 6 speed and going maybe +1front -1-2 on rear would achieve that...or is that the other way around :umm:

.....any who....the trade off will be a buzzy bike at highway speeds but it shouldn't see highway often asI intend on getting a larger 750-1100 range bike for that, been eyeballing I-4 750 xjs lately...oh well

16VGTIDave · Oct 17, 2016

I'd suggest starting with the stock Seca gearing: 16 front / 38 rear. That should feel snappy compared to the Maxim gearing. Check out gearingcommander.com and play with the gearing to get an idea what the changes will make.

I'm sort of stuck with the 17 front to provide a bit more chain clearance from the swingers. With the Seca 38 rear sprocket my bike is revving close to stock Maxim RPM's. Though I've pondered how to make a 16 or even 15 front work. Not that I need a wheelie machine, or the ability to climb mountains...

Jeff0133 · Oct 17, 2016

MerlinDudley said:
Thanks for your reply Jeff, but, it will be cheaper, for me to swap over transmission, as a guy I know wants my 5 speed gearbox, in a straight swap for his 6 speed box! I have no idea why he would want to do this, but I'm not complaining!
So, you think that the 6 speed will just slot in, in place of my 5 speed, without any modification?
Thanks so much for that Info, Jeff!

Merlin

Went out to the garage, took measurements, compared covers, it is the same engine so your swap should be straightforward.

All over the place...Maxim/Seca build

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