Dirt Squirt

[Garyh]

Just bought a ‘73 Dirt Squirt at the Mecum Las Vegas auction last December and was pleased to find this club and the Hodaka Parts web.
The bike I bought has been very well restored, ( looking like new), but has been on static display for several years and never run during that time.
I got it running after rebuilding the carb and gas tank, but it is blowing too much blue smoke and running rough like it is too rich.
Let it run for awhile to get the old oil out/of the pipe and elsewhere but it is still smoking and running rough.
Any ideas before I tear down the top end. (Right side crank seal leaking?)

[Bullfrog]

Clutch side crankshaft seal is a prime suspect. You'll have to split the cases for that one.

Be sure to pressure/vacuum test the engine when you are done - two strokes MUST be airtight. NOTE: I'd highly recommend a pressure test to identify EXACTLY where your leak is before starting the tear down. Odds are it is the seal . . . but it could be somewhere else, and it would be a bummer to replace the seal and get it all back together only to find the leak is still there.
Ed

[ossa95d]

It's possible that the owner had added oil to the cylinder to keep it from seizing while sitting and the crankcase is full. It can take a while to work all of that oil out of the engine and pipe (especially the pipe). A leakdown test is simple to perform and would be very helpful in locating the source of your problem.

[Bullfrog]

"Pop" is right. It is quite possible the symptoms may not relate to a leak. But we agree that the first step is a diagnostic pressure test.

Ed

[Garyh]

Thanks for the advice.
I thought the Rt. Side crank seal was the probable problem.
How do you do a pressure test? Not familiar with how to do that?

[Dale]

There are a number of posts regarding leak down testing here on the forum. Unfortunately,, the built-in search feature is not that great. Here is a link to one such post. viewtopic.php?t=2871

The best way to search the forum, in my opinion, is to go to google.com and enter your search in this format:
site:hodakaforum.com leak down test

[MTrat]

Soapy water is your friend with the leak down test. RH crank seal failure will add pressure to the trans which will exit through the vent below the carb. Again, soapy water can help you track down where the leaks are,

[ossa95d]

By plugging the exhaust port and the carb mount you can carefully pressurize the engine to no more than 6 psi. Ideally it should hold that pressure for 3 minutes, but if it leaks more than 1 psi per minute it has a leak that needs to be addressed. There are leak down pressure test kits that are available commercially, but they are pricey. They can be made yourself if you are somewhat clever.

[ossa95d]

This kit by Motion Pro comes with all the plugs to do just about any two stroke engine, including Hodakas.

[Garyh]

Thank you for help. I will give it a try.