[DucDucGrom]

A friend of mine wanted to buy a grom, I was never interested in them. I spent a weekend driving him around looking at them and trying them out, looking for a deal. After the second day, I told him I wouldn’t pay more than X amount of $$ for one. A couple days later he said found one for me and had already set up the deal. I (a man of my word) showed up, paid the $$ and had a grom before he did..and so it began.

 

[DucDucGrom]

Day 1;
A stretched, lowered, knobbied grom

 

[DucDucGrom]

Cosmetic tear down

 

[DucDucGrom]

Cosmetic play

 

[DucDucGrom]

It's better to ditch that Thailand stretch kit anyways, the chain adjusters are a known point of failure.

Stretch and lowering link were first things ditched !

 

[DucDucGrom]

let there be (OEM) light !

 

[DucDucGrom]

little hyper fender !

 

[DucDucGrom]

First tear down to see how the engine comes apart.
Installed DHM high comp piston at first.

 

[DucDucGrom]

how many miles on the piston?

The photo above is OEM coming out. The high compression piston I ran for a couple hundred miles!

 

[DucDucGrom]

DHM hi-comp piston paired with Finbro 3.0 super head and Finbro ECU

 

[DucDucGrom]

Gave the XR a little make over while waiting on grom parts

 

[DucDucGrom]

Broken… time for a full build…

 

[DucDucGrom]

That piston is tak143. Didn’t want to go any bigger on stock crank. Winter is coming. Good time to split cases

 

[DucDucGrom]

Wrist control… I was very very happy with it. And tried to keep it under 5-6k for a while. But it got the best of me. I wouldn’t hesitate to buy it again. But I have bottom end knock I need to investigate

 

[DucDucGrom]

I did not keep the engine revs under the recommended limit for the recommended time. I probably broke it in for 50-75miles it went with probably 300miles. But I did not have my oil cooler installed and no ARF read out And was hitting 9k-12k revs. Totally my own fault.

 

[DucDucGrom]

I agree, once rings set and are happy.. ride it! Yes I was hoping the finbro ECU would keep it happy enough. But it didn’t.. at least through the paces I was putting it through. I was going to stay long at 143cc just a quick project to see what it was like at that size. And didn’t feel like splitting cases just yet to do crank. Throw the hot 125cc set up back on it to see if it would start and idle and it did, small knock still there. Just got home from work and getting some other projects out of the way before the engine comes apart.
And yes.. I do have big head on
Time to research next kit and additions.. ARacer makes the cart a little pricey. But think it will be worth it if I go bigger than 170cc

 

[DucDucGrom]

update

 

[DucDucGrom]

Went well, removing engine was fine. Pretty straight forward. Tore it apart to try and see what happened… couldn’t tell what went first the crank or the piston.. maybe both at same time. My guess is (stock) crank on this one. Ran it above 10k on stock block all the time.

 

[DucDucGrom]

Rushed a bought a built engine 181 Neo kit (was in mid summer and wanted it to run again) Installed that and started mapping again with aRacer. Dress the bike up a bit.


and then.

 

[DucDucGrom]

strike two !.. still haven’t pulled this one apart. Had to leave for work… i