Stroking a Dolmar 7900

[Fruecrue]

Grab your popcorn boys and girls.
Hold on to your underwear, we’re headed for destruction!

 

[Fruecrue]

Started here:

 

[Fruecrue]

Then here:
http://opeforum.com/threads/dolmar-7900-crank.14381/

 

[Fruecrue]

Now I’m here.
Which is nowhere really, waiting on the crank.
I’m sure the whole process will take time, if I can even do it.
I’ve not done anything like this before so I’m open to any and all feedback and suggestions.

The Solo crank uses different bearings, but the ID is the same, so I’m hoping to get it to fit with standard 6202 and 6203 bearings without work to the bearing pockets.

1mm more stroke isn’t huge, so clearancing the cases should be fine.

 

[Tractorsaw1]

I picked up a solo crank, new bearings & seals also but never made time to tear mine down. Now I am in hunting mode & the wood pile is thin. - will be watching

 

[Deets066]

 

[huskihl]

Anybody here ever compared the insides of the dolmar and solo? Geez, as much as they look alike on the outside, you think the cases would be the same or at least very similar

 

[Fruecrue]

Anybody here ever compared the insides of the dolmar and solo? Geez, as much as they look alike on the outside, you think the cases would be the same or at least very similar

I’m hoping for many similarities.
I’ve read that Solo uses 6302 and 6303 vs. 6202 and 6203 bearings.
63xx are wider and have a larger O.D. Don’t know if the crank is longer overall to make up for the wider bearings. That may present some challenges.

 

[mettee]

This is gonna be good

I was thinking the same thing. The dolmar crank is better than the solo, so I'm wondering if that one company can simply weld and offset grind the dolmar crank. If that is the correct process that is. The rod journal is pressed in so...

 

[Fruecrue]

This is gonna be good

I was thinking the same thing. The dolmar crank is better than the solo, so I'm wondering if that one company can simply weld and offset grind the dolmar crank. If that is the correct process that is. The rod journal is pressed in so...

It’s about $125 to have it trued and welded.

 

[Deets066]

Could the Dolmar crank be taken apart and put back with just the solo rod, then trued and welded?

 

[Deets066]

If need be

 

[Fruecrue]

I’m sure anything could be done at a price.

The Solo crank has a longer stroke which is what I’m after.

Would there be a benefit to changing rod length? I don’t even know at this point what either rod length is.

 

[Fruecrue]

Bearings came of the old crank this morning.

 

[mettee]

Gosh what is the name of that shop that does this work?

Are they able to repair that crank? Or does it need a new rod?

I dont think replacing the dolmar rod with the solo will accomplish the stroke. The stroke is in the swing of the crank. There is a whole case on ebay that has a complete crank inside, I think 150.

 

[Fruecrue]

Falicon is the name of the shop.
Repair would cost more than replacement.
A new crank can be had around $150, but where’s the fun in that?

 

[mettee]

Falicon!

Can you achieve the stroke mod within the repair? Seems like they have to do a new rod and repair the journal. Then they could offset grind... Not sure a small machine exists for this step...but that's how the big stuff goes.

Falicon, stroke and balance is =700 sheep skins

 

[mettee]

Need to get a solo and dolmar crank side by side don't we

 

[Tractorsaw1]

Sooner or later it will happen

 

[Fruecrue]

Sooner or later it will happen

Overall length measurement? From fly thread end to clutch stub?