Help to find model of bike to find parts
 

Before I by a TDR 300cc bike I need help please to find info about it, the seller gave me some pictures and numbers and there is one problem with it that will need a new part, from what I know the part is for the rear chain tensioner as the chain is always falling off and the problem probably stems to the rear wheel not being on right as he mentioned it is on wrong and a bit sideways plus its missing the chain guard and chain rail below the rear sprocket.

on the motor is stamped:
170FMN
9L131670

and Ive tried a free VIN number lookup but there is no info, I know from the tenth character on the VIN "L" its either a 1990 or 2020 year bike but it looks like a 2020 instead of a 1990. I will contact TDR soon but I thought I would try here first

Edit:
I now know its a 2020 TDR XVW300 with some of the green "sport" stickers removed, with this now known I am looking for a rear chain guide but not the original one because it was a flimsy single piece of metal instead ill look for a real chain guide with plastic guide rails

I haven't seen that engine model number. But the 170 part suggests about a 240cc displacement (70 is probably the bore size). Hawks, Storm, and others use a 169Fxx (69mm bore) engine, and 172Fxx engines (249cc) are in some other models.

The TDR you got seems to be closely related to the Hawk and Storm. Not sure why they named it a 300. Displacemnt is closer to 240cc.

BUT, that rear axel and swingarm design is VERY COMMON on these bikes. You should have no problem installing a universal rear axel tensioner. Here is a picture of a Hawk tensioner:

Attachment 30503

I don't know why you can't set the tension. You seem to have the parts there. Here is one from ebay. Google this description and it should find the listing:

"2X Rear Wheel Chain Adjuster Set Replacement For Hawk 250 Carb and DLX Models"
This one is from China ($16.99) plus ~$6 shipping, so it will take a week or two to get here. I saw a used rear axel tensioner on ebay for $20 (one side). But you probably have tall of tghese parts. It just needs to be set up and tensioned properly.

Attachment 30504

Be careful...
Don't attempt to secure the axel by overtightening it!!!
This will deform the swingarm box. It isn't made to withstand lots of compression!

It also looks as though the wheel spacer is incorrect for that side, it appears to be way too wide, putting the wheel too far away from proper alignment with the front sprocket.

I think that the spacing is OK. The chain is just draped on the axel near the swingarm back there.

Frankie...I think it is just out of adjustment. There is a vertical line on the angled plate that you should be able to set on the same position on each side (hash marks on the swingarm on both sides). Get them on the same position, with about 1.5-2.0 cm chain movement.

I do notice that you have inverted front forks. That is an upgrade compared to the Hawk. This might be a Bashan made bike. But that engine designation is off. Are you sure it isn't a 169FMN? 170 engines are twin cylinders (the ones I can find).

I am wrong about the engine. It has 270cc displacement. Surprising! I used the displacement calculator on Spicer webpage to verify it (https://spicerparts.com/calculators/...ent-calculator).
Here are specs on the engine (more than 18hp, stock!):

Bore & Stroke (mm): 70.2x70
Compression Ratio: 9.2:1
Cylinders: 1
Displacement (ml): 270.8
Engine Type: oil-cooled 4-stroke
Max power (kw/(r/min)): 13.5Kw/8000r/min
Max Torque (N.m/(r/min)): 19.5N.m/5500±500r/min