Let's take a look at a Team Associated Pro 21 Nitro engine Thunder Tiger 21R from a Monster GT

[@rcduck]

The low end speed needle is still adjustable from the slide side but have to remove that ball connector. great video Todd keep them coming 👍

[@speedgears1236]

Thanks for your nitro videos. I love Team Associated

[@valuerc2664]

Awesome videos, I really enjoy watching them.

[@LDizzy1]

My original Thunder Tiger Pro 21 is the race version(9474). It has the three needle carb (9210) with allen head bolts to adjust the mixture. It comes with the (AA2040) piston & sleeve set, which has extra bypass cuts put into the sleeve and also the top of the cooling head is a complete circle. The crankcase is stamped 21 pro on both sides. The Associated rebrand purple & blue pro 21's have the cross cut cooling head. They have pro 21r stamped on the crankcase. They use the two needle carb. It also uses the standard piston and sleeve set (AA0549) without the extra cuts to the sleeve. If you take off the ball end on those carbs an replace it with a standard ball link, you can have access to the third needle.

[@NitroTalkwithTodd]

I was unaware of that version of the Pro 21, very interesting.

[@nwo4life746]

Kip goin great worck i like your video

[@islandrc-duke1972]

great video and information,nice engine

[@stevelucchini87]

Hello, great video and thank you for that. I have the Schumacher 21XTR truck that came with a three speed. It came with a thunder tiger pro 21 with the purple head. I have one important question to ask. Are the motors that you’re showing pretty much the same and will accept the same carburetor,and gaskets, between them? I’m looking for parts, including that odd exhaust manifold O-ring type gasket. When I try to look for parts for my motor, nothing is in stock, but I’m beginning to think there are other motors under different part numbers that are the same. Any info would be nice so I can restore this motor. Mostly the Roto start and the gaskets for it. Thank you so much.

[@NitroTalkwithTodd]

Yes, they are the same, but there are a few variations. I have a couple of the purple headed pro 21s from Schumachers and I've never seen a rotostart backplate on one. They usually have an all metal direct drive shaft starting setup. All of mine either have those, or the associated combo pull start/direct drive shaft start. I just looked at the pro 21 exploded view, it doesn't show the exhaust gasket or a part number for it. There is a gasket set and an o-ring set, neither include the exhaust gasket. And a quick search didn't come up with much either. So you'll have to fashion your own. I have used a standard silicone o-ring, and I've also used the middle section cut out of a standard exhaust gasket. That's a fairly easy problem to solve. The starting system on the other hand may give you a bit more grief. I agree that the Schumacher parts will be harder to find and more expensive. So if you go associated, #25345 is the complete set, backplate and pull/shaft starter. This is everything you need to convert a Schumacher. I cannot find any for sale. You can buy the backplate and pull starter separately, the backplate is available, the pull starter is not. Might have better luck keeping your eyes open on eBay for a complete pro 21 for parts. Have you thought about bump starting? I'm not sure if the XTR has flywheel access but it might be possible. Quick question, is your current starting issue a stripped out hex where you insert the starting shaft, or are you missing parts?

[@stevelucchini87]

@@NitroTalkwithTodd Thank you for the reply and info. The hex for the E-Start is ok, but I would like to replace the one-way bearing and shaft in it. I am just restoring an Schumacher XTR 3E Nitro Truck three speed which has this stock 21 pro R nitro engine in it. Looking to restore it with original OEM parts which is hard to find as you said. The hardest part to find for these engines is the Circlips that go on each side of the ristpin in the piston. I guess I will have to reuse the old ones. Do you know where to find these Circlips for these engines? Sorry for the late reply. Thank You ..... Steve

[@Rod-we6he]

What motor tooth ? did you use?

[@rcaddictgarage]

👍

[@jayp9299]

I have intigy shocks on my T-max